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(2010) Abudalo, R.A., Ryan, J.N., Harvey, R.W., Metge, D.W. and Landkamer, L. Influence of organic matter on the transport of Cryptosporidium parvum oocysts in a ferric oxyhydroxide-coated quartz sand saturated porous medium. Water Research 44(4), 1104-1113.

 

ABSTRACT
To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using micro-electrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter had no significant effect on the zeta potential of the oocysts. Low concentrations of dissolved organic matter were responsible for reversing the charge of the ferric oxyhydroxide-coated sand surface from positive to negative. The charge reversal and accumulation of negative charge on the ferric oxyhydroxide-coated sand led to increases in oocyst breakthrough and decreases in oocyst collision efficiency with increasing dissolved organic matter concentration. The increase in dissolved organic matter concentration from 0 to 20 mg L-1 resulted in a two-fold decrease in the collision efficiency.
KEYWORDS:
Cryptosporidium parvum; Oocyst; Transport; Organic matter; Ferric oxyhydroxide; Zeta potential humic-acid adsorption; point flow cell; escherichia-coli; colloid transport; bank filtration; iron-oxide; mineral surfaces; ionic-strength; physicochemical filtration; electrophoretic mobility

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(2010) Ahn, M.C., Kim, B., Holsen, T.M., Yi, S.M. and Han, Y.J. Factors influencing concentrations of dissolved gaseous mercury (DGM) and total mercury (TM) in an artificial reservoir. Environmental Pollution 158(2), 347-355.

 

ABSTRACT
The effects of various factors including turbidity, pH, DOC, temperature, and solar radiation on the concentrations of total mercury (TM) and dissolved gaseous mercury (DGM) were investigated in an artificial reservoir in Korea. Episodic total mercury accumulation events occurred during the rainy season as turbidity increased, indicating that the TM concentration was not controlled by direct atmospheric deposition. The DGM concentration in surface water ranged from 3.6 to 160 pg/L, having a maximum in summer and minimum in winter. While in most previous studies DGM was controlled primarily by a photo-reduction process, DGM concentrations tracked the amount of solar radiation only in winter when the water temperature was fairly low in this study. During the other seasons microbial transformation seemed to play an important role in reducing Hg(II) to Hg(0). DGM increased as dissolved organic carbon (DOC) concentration increased (p-value < 0.01) while it increased with a decrease of pH (p-value < 0.01).
KEYWORDS:
TM (total mercury); DGM (dissolved gaseous mercury); Reduction; pH; DOC (dissolved organic carbon) fresh-water lakes; st-lawrence-river; humic substances; atmospheric mercury; solar-radiation; aquatic environments; florida everglades; seasonal-variation; elemental mercury; divalent mercury

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(2010) Altunkaynak, A. and Wang, K.H. Triple diagram models for prediction of suspended solid concentration in Lake Okeechobee, Florida. Journal of Hydrology 387(3-4), 165-175.

 

ABSTRACT
Lake Okeechobee in Florida is a major component of the greater Everglades hydrologic system and provides a number of valuable uses to society and nature, such as water supply, navigation, wildlife habitat, and fishery. Suspended solid concentration (SSC) affects directly the lake's conditions for some of these applications. Therefore, accurate prediction of SSC can enhance the management of the water quality and the long-term protection of Lake Okeechobee. Extensive data, including wind speed, flow velocity, flow direction and SSC, have been collected. Models for predicting suspended solid concentration based on 10 different scenarios are developed using these measurements. Data are divided into two groups as training and testing for the construction of the models. SSC is predicted by the Kriging interpolation technique. Criterions of mean relative error, root mean squared error and coefficient of efficiency (CE) are used to determine the prediction errors of the developed models. In general, mean relative error is below 7% and coefficient of efficiency stays above 0.92 for the models presented. Graphs, results, and interpretations are given in detail in this paper.
KEYWORDS:
Contour map; Prediction; Kriging optimum interpolation technique; Lake Okeechobee; Sediment/water interaction; Model wave height

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(2010) Bao, K.S., Yu, X.F., Jia, L. and Wang, G.P. Recent Carbon Accumulation in Changbai Mountain Peatlands, Northeast China. Mountain Research and Development 30(1), 33-41.

 

ABSTRACT
The Changbai Mountain range is a well-known and important mountain chain in northeast China, bordering the Korean Peninsula in the south. It is also one of the areas most sensitive to global change. Massive peatlands that play a key role in the global carbon (C) cycle are found in this region. Estimating and assessing C dynamics in Changbai Mountain peatlands is of great importance to local sustainable development. Dry bulk density and C content analyses based on 8 selected peat cores dated by Pb-210 were used to estimate recent rates of carbon accumulation (RERCA, g C m(-2) yr(-1)) in Changbai Mountain peatlands. RERCA ranged from 124.2 to 292.8 g C m(-2) yr(-1) (average 199.6 +/- 60.9 g C m(-2) yr(-1)). Obvious increasing trends in RERCA were observed in all peat cores. The C pool for 200 years was 38.5-52.1 kg C m(-2), which can supplement the database of C pools for Changbai Mountain ecosystems. The Pb-210 radiometric technique was tested and found to be a useful study method for recent terrestrial carbon sequestration. This study could contribute to a better understanding of rarely studied mountain peatlands in China and may be useful to global mountain and climate change research.
KEYWORDS:
Peatlands; carbon pool; recent rate of carbon accumulation (RERCA); Pb-210 dating; climate change research; Changbai Mountains; northeast China organic-matter accumulation; term nutrient accumulation; ombrotrophic peat bogs; climate-change; rates; ecosystem; holocene; finland; mires; everglades

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(2010) Barr, J.G., Engel, V., Fuentes, J.D., Zieman, J.C., O'Halloran, T.L., Smith, T.J. and Anderson, G.H. Controls on mangrove forest-atmosphere carbon dioxide exchanges in western Everglades National Park. Journal of Geophysical Research-Biogeosciences 115(

 

ABSTRACT
We report on net ecosystem production (NEP) and key environmental controls on net ecosystem exchange (NEE) of carbon dioxide (CO2) between a mangrove forest and the atmosphere in the coastal Florida Everglades. An eddy covariance system deployed above the canopy was used to determine NEE during January 2004 through August 2005. Maximum daytime NEE ranged from -20 to -25 mu mol (CO2) m(-2) s(-1) between March and May. Respiration (R-d) was highly variable (2.81 +/- 2.41 mu mol (CO2) m(-2) s(-1)), reaching peak values during the summer wet season. During the winter dry season, forest CO2 assimilation increased with the proportion of diffuse solar irradiance in response to greater radiative transfer in the forest canopy. Surface water salinity and tidal activity were also important controls on NEE. Daily light use efficiency was reduced at high (>34 parts per thousand (ppt)) compared to low (<17 ppt) salinity by 46%. Tidal inundation lowered daytime R-d by similar to 0.9 mu mol (CO2) m(-2) s(-1) and nighttime R-d by similar to 0.5 mmol (CO2) m(-2) s(-1). The forest was a sink for atmospheric CO2, with an annual NEP of 1170 +/- 127 g C m(-2) during 2004. This unusually high NEP was attributed to year-round productivity and low ecosystem respiration which reached a maximum of only 3 g C m(-2) d(-1). Tidal export of dissolved inorganic carbon derived from belowground respiration likely lowered the estimates of mangrove forest respiration. These results suggest that carbon balance in mangrove coastal systems will change in response to variable salinity and inundation patterns, possibly resulting from secular sea level rise and climate change.
KEYWORDS:
florida coastal everglades; rhizophora-mangle l.; gas-exchange; physiological processes; avicennia-germinans; spatial variability; soil respiration; deciduous forest; organic-matter; water-vapor

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(2010) Barringer, J.L., Riskin, M.L., Szabo, Z., Reilly, P.A., Rosman, R., Bonin, J.L., Fischer, J.M. and Heckathorn, H.A. Mercury and methylmercury dynamics in a coastal plain watershed, New Jersey, USA. Water Air and Soil Pollution 212(1-4), 251-273.

 

ABSTRACT
The upper Great Egg Harbor River watershed in New Jersey's Coastal Plain is urbanized but extensive freshwater wetlands are present downstream. In 2006-2007, studies to assess levels of total mercury (THg) found concentrations in unfiltered streamwater to range as high as 187 ng/L in urbanized areas. THg concentrations were < 20 ng/L in streamwater in forested/wetlands areas where both THg and dissolved organic carbon concentrations tended to increase while pH and concentrations of dissolved oxygen and nitrate decreased with flushing of soils after rain. Most of the river's flow comes from groundwater seepage; unfiltered groundwater samples contained up to 177 ng/L of THg in urban areas where there is a history of well water with THg that exceeds the drinking water standard (2,000 ng/L). THg concentrations were lower (< 25 ng/L) in unfiltered groundwater from downstream wetland areas. In addition to higher THg concentrations (mostly particulate), concentrations of chloride were higher in streamwater and groundwater from urban areas than in those from downstream wetland areas. Methylmercury (MeHg) concentrations in unfiltered streamwater ranged from 0.17 ng/L at a forest/wetlands site to 2.94 ng/L at an urban site. The percentage of THg present as MeHg increased as the percentage of forest + wetlands increased, but also was high in some urban areas. MeHg was detected only in groundwater < 1 m below the water/sediment interface. Atmospheric deposition is presumed to be the main source of Hg to the wetlands and also may be a source to groundwater, where wastewater inputs in urban areas are hypothesized to mobilize Hg deposited to soils.
KEYWORDS:
Mercury; Methylmercury; Wetlands; Streamwater; Groundwater; Land use dissolved organic-carbon; southern new-jersey; in-ground water; northern wisconsin; florida everglades; humic substances; transport; matter; deposition; chemistry

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(2010) Bellinger, B.J., Gretz, M.R., Domozych, D.S., Kiemle, S.N. and Hagerthey, S.E. Composition of Extracellular Polymeric Substances from Periphyton Assemblages in the Florida Everglades. Journal of Phycology 46(3), 484-496.

 

ABSTRACT
In wetland habitats, periphyton is a common component of open-water areas with species assemblage determined by local water quality. Extracellular polymeric substances (EPS) secreted by algae and bacteria give structure to periphyton, and differences in EPS chemistry affect the functional roles of these polymers. The Florida Everglades provide a unique opportunity to study compositional differences of EPS from distinctive algal assemblages that characterize areas of differing water chemistry. Water conservation area (WCA)-1 is a soft-water impoundment; periphyton was loosely associated with Utricularia stems and amorphous in structure, with a diverse desmid and diatom assemblage, and varying cyanobacterial abundance. Extracellular polymers were abundant and were loosely cell-associated sheaths and slime layers in addition to tightly cell-associated capsules. The EPS were complex heteropolysaccharides with significant saccharide residues of glucose, xylose, arabinose, and fucose. Carboxylic acids were also prominent, while ester sulfates and proteins were small components. Structured, cohesive cyanobacteria-dominated periphyton was observed in WCA-2A, a minerotrophic impoundment, and filaments were heavily encrusted with calcium carbonate and detrital matter. EPS were primarily cell-associated sheaths, and polymer residues were dominated by glucose, xylose, fucose, and galactose, with uronic acids also a significant component of the polymers. Principal components analysis revealed that periphyton community assemblage determined the monosaccharide composition of EPS, which ultimately determines a range of biogeochemical processes within the periphyton.
KEYWORDS:
cyanobacteria; desmids; EPS; minerotrophy; periphyton; polysaccharides different colony morphologies; marine stromatolites bahamas; benthic diatoms; intracellular chrysolaminaran; biochemical-characterization; microbial-degradation; nostoc cyanobacteria; intertidal sediments; chemical-composition; northern everglades

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(2010) Bellinger, B.J. and Hagerthey, S.E. Presence and Diversity of Algal Toxins in Subtropical Peatland Periphyton: The Florida Everglades, Usa1.
Journal of Phycology 46(4), 674-678.

 

ABSTRACT
Production of toxic secondary metabolites by cyanobacteria, collectively referred to as cyanotoxins, has been well described for eutrophied water bodies around the world. However, cohesive cyanobacterial mats also comprise a significant amount of biomass in subtropical oligotrophic wetlands. As these habitats generally do not support much secondary production, cyanotoxins, coupled with other physiological attributes of cyanobacteria, may be contributing to the minimized consumer biomass. Periphyton from the Florida Everglades has a diverse and abundant cyanobacterial assemblage whose species produce toxic metabolites; therefore, by screening periphyton representative of the greater Everglades ecosystem, six different cyanotoxins and one toxin (domoic acid) produced by diatoms were identified, ranging in content from 3 x 10-9 to 1.3 x 10-6 (g center dot g-1), with saxitoxin, microcystin, and anatoxin-a being the most common. While content of toxins were generally low, when coupled with the tremendous periphyton biomass (3-3,000 g center dot m-2), a significant amount of cyanotoxins may be present. While the direct effects of the toxins identified here on the local grazing community need to be determined, the screening process utilized proved effective in showing the broad potential of periphyton to produce a variety of toxins.
KEYWORDS:
cyanotoxins; Everglades; grazing; periphyton; secondary production benthic cyanobacterium phormidium; community structure; protein expression; microcystin-lr; lyngbya-wollei; water; patterns; microalgae; australia; fish

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(2010) Bennett, B.C. An Everglades Providence: Marjory Stoneman Douglas and the American Environmental Century.
Agricultural History
84(4), 560-561.

 

ABSTRACT (none)
KEYWORDS:
Marjory Stoneman Douglas, Florida Everglades, Environmental history

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(2010) Bhadha, J.H. and Jawitz, J.W. Characterizing deep soils from an impacted subtropical isolated wetland: implications for phosphorus storage.
Journal of Soils and Sediments 10(3), 514-525.

 

ABSTRACT
Soils within the Lake Okeechobee drainage basin, FL, USA, have been impacted by beef cattle and dairy operations and the landscape ditched and drained to facilitate stocking and grazing pastures. Restoring wetlands located on pastures has been proposed to reduce overland loss of phosphorus (P) by retaining it within the soils. However, soil properties of deeper horizons within impacted wetlands are rarely investigated due to the assumption that most dominant biogeochemical interactions occur at the soil-water interface. In this paper, we investigate soil properties up to 160 cm below the surface from an impacted isolated wetland and its surrounding upland pasture. Four intact soil cores were collected using the vibracoring technique, sectioned at 2-cm intervals, and analyzed for organic matter content by loss on ignition, total P by acid persulfate digestion, and water-soluble P using 0.01-M KCl solution. Bulk density and digital imaging were conducted using a multisensor core logger. Clay-sized phyllosilicates were identified using a computer-controlled X-ray diffractometer. Saturated hydraulic conductivity was measured using the slug-out technique, and the Hvorslev method was used to evaluate results. Unobliterated stratification was observed within the wetland in contrast to the pedologically formed A, E, and B horizons within the upland. The presence of clay horizons composed of smectite and kaolinite was dominant below 120 cm, posing potential hydrological and chemical implications, such as low conductivity and higher P sorption capacity. Saturated hydraulic conductivity of the soils was 1.22 m day(-1) (+/- 0.4). Diagnostic features such as increase in bulk density due to compaction, and the "red-edge effect" were useful in correlating the effect of cattle activity and hydrology on soil profiles. Soil organic matter content (38-48%) and total P (100-600 mg kg(-1)) concentrations were highest and well-correlated (r (2) = 0.81) at the surface. However, a significant amount of P was also present in the deeper horizons associated with clay. The deeper clay horizons account for up to 25% of P per hectare of the entire soil profile. These estimates are nontrivial and need to be accounted for while dealing with belowground P budgets, especially because subsurface lateral flows are dominant within the region.
KEYWORDS:
Impacted soils; Isolated wetlands; Lake Okeechobee; Phosphorus florida everglades; organic-matter; waste-water; sediments; nutrient; retention; pasture; release; marsh; decomposition

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(2010) Bostic, E.M., White, J.R., Corstanje, R. and Reddy, K.R. Redistribution of Wetland Soil Phosphorus Ten Years after the Conclusion of Nutrient Loading. Soil Science Society of America Journal 74(5), 1808-1815.

 

ABSTRACT
There is considerable concern about ecological recovery in wetlands that have been enriched with P; however, there are few long-term studies tracking the distribution of the soil P after the termination of P loading. The Blue Cypress Marsh Conservation Area in Florida contains areas with elevated soil P levels from historical loading. The local spatial variation of soil P was determined in a 750- by 150-m area proximal to the historic surface water inflow point and a second area of the same size located in the center of the marsh with no record of historical P impacts. The average soil total P was estimated at 847 mg kg(-1) in the P-enriched area and 643 mg kg-1 in the marsh interior (unenriched). When compared with previously determined historical data, it was estimated that soil P has decreased in the P-enriched area by about 61%. Meanwhile, there was an increase of 82% in P within the unenriched area during this same time period. These results suggest that P has been mobilized from the impacted areas toward the unimpacted marsh along the water flow patterns in the wetland. These observations have implications for restoration of high-P wetland systems. Remobilization from P-impacted to unimpacted areas can expand the area of increased nutrients despite termination of P inputs into the marsh. If remobilization predominates over burial, then it is also unlikely that the overall nutrient status of the system will return to pre-impact levels within a reasonable management time frame (<25 yr).
KEYWORDS:
water treatment wetland; subtropical wetland; florida everglades; microbial biomass; alum application; marsh; enrichment; vegetation; retention; phosphate

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(2010) Brix, H., Lorenzen, B., Mendelssohn, I.A., McKee, K.L. and Miao, S.L. Can differences in phosphorus uptake kinetics explain the distribution of cattail and sawgrass in the Florida Everglades ? Bmc Plant Biology 10(

 

ABSTRACT
Background: Cattail (Typha domingensis) has been spreading in phosphorus (P) enriched areas of the oligotrophic Florida Everglades at the expense of sawgrass (Cladium mariscus spp. jamaicense). Abundant evidence in the literature explains how the opportunistic features of Typha might lead to a complete dominance in P-enriched areas. Less clear is how Typha can grow and acquire P at extremely low P levels, which prevail in the unimpacted areas of the Everglades. Results: Apparent P uptake kinetics were measured for intact plants of Cladium and Typha acclimated to low and high P at two levels of oxygen in hydroponic culture. The saturated rate of P uptake was higher in Typha than in Cladium and higher in low-P acclimated plants than in high-P acclimated plants. The affinity for P uptake was twofold higher in Typha than in Cladium, and two- to three-fold higher for low-P acclimated plants compared to high-P acclimated plants. As Cladium had a greater proportion of its biomass allocated to roots, the overall uptake capacity of the two species at high P did not differ. At low P availability, Typha increased biomass allocation to roots more than Cladium. Both species also adjusted their P uptake kinetics, but Typha more so than Cladium. The adjustment of the P uptake system and increased biomass allocation to roots resulted in a five-fold higher uptake per plant for Cladium and a ten-fold higher uptake for Typha. Conclusions: Both Cladium and Typha adjust P uptake kinetics in relation to plant demand when P availability is high. When P concentrations are low, however, Typha adjusts P uptake kinetics and also increases allocation to roots more so than Cladium, thereby improving both efficiency and capacity of P uptake. Cladium has less need to adjust P uptake kinetics because it is already efficient at acquiring P from peat soils (e.g., through secretion of phosphatases, symbiosis with arbuscular mycorrhizal fungi, nutrient conservation growth traits). Thus, although Cladium and Typha have qualitatively similar strategies to improve P-uptake efficiency and capacity under low P-conditions, Typha shows a quantitatively greater response, possibly due to a lesser expression of these mechanisms than Cladium. This difference between the two species helps to explain why an opportunistic species such as Typha is able to grow side by side with Cladium in the P-deficient Everglades.
KEYWORDS:
typha-latifolia l; cladium-jamaicense cyperaceae; eutrophic swamp habitats; internal gas-transport; soil-phosphorus; convective throughflow; phosphate availability; phragmites-australis; northern everglades; redox intensity

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(2010) Brooks, W.R. and Jordan, R.C. Enhanced interspecific territoriality and the invasion success of the spotted tilapia (Tilapia mariae) in South Florida. Biological Invasions 12(4), 865-874.

 

ABSTRACT
South Florida's freshwaters are amongst the most invaded in the world with 34 naturalized fish species. How these non-natives affect the local native fish populations, however, is largely unknown. Native sunfish of the genus Lepomis are important as predators in structuring fish and invertebrate assemblages in the swamps and seasonal wet prairies of the Big Cypress Swamp and Florida Everglades. The spotted tilapia, Tilapia mariae, is a successful West African invader that exhibits territorial and spawning behavior that closely matches that of native Lepomis sunfishes. We tested the hypothesis that Lepomis sunfishes and T. mariae would compete when space was limiting. Additionally, we predicted that T. mariae, because of their aggressiveness, would be more successful in acquiring space. We collected juveniles of both groups from Big Cypress National Preserve, Everglades National Park, and the South Florida Water Management District canal system for laboratory trials in which likely competitive interactions were staged and observed. T. mariae were bolder and more aggressive than Lepomis sunfishes. T. mariae residents resisted all intruders whereas 30% of Lepomis sunfish residents were ejected. We surmise that these enhanced behaviors of T. mariae are an important component of their success in South Florida. The continued spread of T. mariae populations throughout South Florida into natural habitats suggests an increasing potential to affect the quality of spawning habitat available for Lepomis sunfishes and warrants a renewed focus on T. mariae as a non-native species of special concern.
KEYWORDS:
Big cypress swamp; Competitive interactions; Fish invasions; Florida Everglades; Interspecific competition; Lepomis sunfish; South Florida; Spotted tilapia; Territorial behavior fresh-water fishes; everglades; california; boulenger; cichlidae; patterns; biology; wetland; impact

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(2010) Brown, J.L. Federal Funding Advances Everglades Restoration. Civil Engineering 80(4), 16.

 

ABSTRACT (none)
KEYWORDS:
Everglades, federal funding, Everglades restoration

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(2010) Campbell, J.W., Waters, M.N., Tarter, A. and Jackson, J. Heavy Metal and Selenium Concentrations in Liver Tissue from Wild American Alligator (Alligator Mississippiensis) Livers near Charleston, South Carolina. Journal of Wildlife Diseases 46(4), 1234-1241.

 

ABSTRACT
Liver samples from 3.3 wild American alligators (Alligator mississippiensis) livers from the Charleston, South Carolina, area were analyzed for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb), and selenium (Se) concentrations. Alligators are top predators and are considered a good biomonitoring species for various toxins, including heavy metals. Alligators from other areas in the US have shown high concentrations of mercury and other heavy metals, but the Charleston area, which is highly industrialized, has not been investigated. We found wide variation in hepatic heavy metal and selenium concentrations among alligators. Length and sex did not show a strong relationship with any metal based on statistical analysis. However, cluster analysis revealed three groupings of alligators based on liver metal concentrations. Alligators with low Se:Hg ratios also had high concentrations of Fig. Due to the wide variation in metal concentrations among individual alligators, we postulate that individual diet and microhabitat usage could be the cause for this variation.
KEYWORDS:
Alligator mississippiensis; American alligator; heavy metals; lead; mercury; selenium; South Carolina fresh-water fish; florida everglades; mercury concentrations; lead; contaminants; lakes

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(2010) Cardel, Y.J. and Koptur, S. Effects of Florivory on the Pollination of Flowers: An Experimental Field Study with a Perennial Plant.
International Journal of Plant Sciences 171(3), 283-292.

 

ABSTRACT
Plants experience damage to both their vegetative and their reproductive parts. Loss of leaf area can affect subsequent photosynthesis and resources available for growth and reproduction; damage to flowers can result in loss of ovules and seeds by consumption, but herbivory may also disfigure flowers, interfering with their functions of attracting and rewarding pollinators. We examined natural populations of the butterfly pea, Centrosema virginianum, in pine rockland habitat in Everglades National Park (intact habitat) and a pine rockland fragment in suburban Miami-Dade County to answer the following questions: (1) What is the breeding system of C. virginianum? (2) What are the pollinators of this species in southern Florida pine rocklands? And (3) how are flower herbivores affecting pollinator visitation and subsequent fruit set? Controlled hand-pollination experiments revealed this species to be self-compatible but requiring visitation/pollination for fruit set. Cross-pollinated flowers and open-pollinated flowers set substantially more seed per fruit than did self-pollinated flowers. Flowers are visited by a variety of bees (Bombus pensylvanicus, Xylocopa micans, Megachile spp., and Melissodes spp.), which serve as pollinators. Flowers were produced abundantly in areas that had experienced recent fires, and roughly half of the flowers were damaged by one of two florivore guilds (blister beetles that ate the flowers and petal-sucking flies in the family Agromyzidae). Damaged flowers were visited much less frequently by pollinators than were undamaged flowers, and, consequently, they set many fewer fruit and much less seed. We conclude that florivory is a major impediment to successful pollination and plant sexual reproduction of C. virginianum in areas where the species naturally occurs.
KEYWORDS:
florivory; pollination; bees; blister beetles; Agromyzidae; flies; breeding system pollen-ovule ratios; floral herbivory; breeding systems; mating system; wild radish; patch size; fitness; consequences; evolution; ecology

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(2010) Carriger, J.F., Hoang, T.C. and Rand, G.M. Survival Time Analysis of Least Killifish (Heterandria formosa) and Mosquitofish (Gambusia affinis) in Acute Exposures to Endosulfan Sulfate. Archives of Environmental Contamination and Toxicology 58(4), 1015-1022.

 

ABSTRACT
Single-species flow-through toxicity tests were conducted to determine the times-to-death of two indigenous fish to South Florida-least killifish (Heterandria formosa) and mosquitofish (Gambusia affinis)-from acute exposure to endosulfan sulfate. Mortalities were recorded within 8-h periods from test initiation to termination at 96 h. The 96-h LC(50)s for least killifish and mosquitofish estimated using the trimmed-Spearman-Karber method were 2.0 and 2.3 mu g/l, respectively. An accelerated failure time model was used to estimate times to death at selected concentrations. Data were fit to log-normal, log-logistic, and Weibull distributions. Acute toxicity data fit to the Weibull distribution produced a better relative fit than log-normal or log-logistic distributions for both toxicity tests. The survival-time profiles and associated statistics illustrate the benefit of considering exposure duration as well as concentration when predicting acute risk to species' populations. Both toxicity tests had similar outcomes from exposure to endosulfan sulfate, with least killifish being slightly more likely to die at lower concentrations and shorter time periods than mosquitofish. From the models generated by the toxicity tests, times-to-death for least killifish and mosquitofish were estimated for environmentally relevant concentrations of total endosulfan at a site of concern in South Florida. When the results from the current toxicity tests were compared to environmental concentrations from previous screening-level ecological risk assessments, the durations necessary to potentially kill 10% or more of the populations of the two native south Florida fish species were estimated to be 77 and 96 h for least killifish and mosquitofish, respectively. However, the exposure values included the alpha and beta isomers as well as endosulfan sulfate; therefore, an understanding of their toxicity might be important in understanding the survival dynamics of fish species in endosulfan sulfate-contaminated sites
KEYWORDS:
south Florida; pesticides; sediment; everglades; mortality; canals

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(2010) Castaneda-Moya, E., Twilley, R.R., Rivera-Monroy, V.H., Zhang, K.Q., Davis, S.E. and Ross, M. Sediment and Nutrient Deposition Associated with Hurricane Wilma in Mangroves of the Florida Coastal Everglades. Estuaries and Coasts 33(1), 45-58.

 

ABSTRACT
The distribution of mangrove biomass and forest structure along Shark River estuary in the Florida Coastal Everglades (FCE) has been correlated with elevated total phosphorus concentration in soils thought to be associated with storm events. The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to quantify sediment deposition and nutrient inputs in FCE mangrove forests associated with this storm event and to evaluate whether these pulsing events are sufficient to regulate nutrient biogeochemistry in mangrove forests of south Florida. We sampled the spatial pattern of sediment deposits and their chemical properties in mangrove forests along FCE sites in December 2005 and October 2006. The thickness (0.5 to 4.5 cm) of hurricane sediment deposits decreased with distance inland at each site. Bulk density, organic matter content, total nitrogen (N) and phosphorus (P) concentrations, and inorganic and organic P pools of hurricane sediment deposits differed from surface (0-10 cm) mangrove soils at each site. Vertical accretion resulting from this hurricane event was eight to 17 times greater than the annual accretion rate (0.30+/- 0.03 cm year(-1)) averaged over the last 50 years. Total P inputs from storm-derived sediments were equivalent to twice the average surface soil nutrient P density (0.19 mg cm(-3)). In contrast, total N inputs contributed 0.8 times the average soil nutrient N density (2.8 mg cm(-3)). Allochthonous mineral inputs from Hurricane Wilma represent a significant source of sediment to soil vertical accretion rates and nutrient resources in mangroves of southwestern Everglades. The gradient in total P deposition to mangrove soils from west to east direction across the FCE associated with this storm event is particularly significant to forest development due to the P-limited condition of this carbonate ecosystem. This source of P may be an important adaptation of mangrove forests in the Caribbean region to projected impacts of sea-level rise.
KEYWORDS:
Hurricane Wilma; Sediment deposition; Mangroves; Accretion; Nutrient biogeochemistry; Florida Everglades seagrass thalassia-testudinum; rising sea-level; climate-change; caribbean hurricanes; lightning strikes; soil-phosphorus; organic-matter; south florida; wetland soils; national-park

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(2010) Ceyhun, O. and Yalcin, A. Remote sensing of water depths in shallow waters via artificial neural networks.
Estuarine Coastal and Shelf Science 89(1), 89-96.

 

ABSTRACT
Determination of the water depths in coastal zones is a common requirement for the majority of coastal engineering and coastal science applications. However, production of high quality bathymetric maps requires expensive field survey, high technology equipment and expert personnel. Remotely sensed images can be conveniently used to reduce the cost and labor needed for bathymetric measurements and to overcome the difficulties in spatial and temporal depth provision. An Artificial Neural Network (ANN) methodology is introduced in this study to derive bathymetric maps in shallow waters via remote sensing images and sample depth measurements. This methodology provides fast and practical solution for depth estimation in shallow waters, coupling temporal and spatial capabilities of remote sensing imagery with modeling flexibility of ANN. Its main advantage in practice is that it enables to directly use image reflectance values in depth estimations, without refining depth-caused scatterings from other environmental factors (e.g. bottom material and vegetation). Its function-free structure allows evaluating nonlinear relationships between multi-band images and in-situ depth measurements, therefore leads more reliable depth estimations than classical regressive approaches. The west coast of the Foca, Izmir/Turkey was used as a test bed. Aster first three band images and Quickbird pan-sharpened images were used to derive ANN based bathymetric maps of this study area. In-situ depth measurements were supplied from the General Command of Mapping, Turkey (HGK). Two models were set, one for Aster and one for Quickbird image inputs. Bathymetric maps relying solely on in-situ depth measurements were used to evaluate resultant derived bathymetric maps. The efficiency of the methodology was discussed at the end of the paper. It is concluded that the proposed methodology could decrease spatial and repetitive depth measurement requirements in bathymetric mapping especially for preliminary engineering application.
KEYWORDS:

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(2010) Chen, C.S. Abundance trends of two neon flying squid (Ommastrephes bartramii) stocks in the North Pacific. Ices Journal of Marine Science 67(7), 1336-1345.

 

ABSTRACT
Two stocks of neon flying squid (Ommastrephes bartramii) have been identified in the North Pacific, with differing life- history traits and geographic distributions, one in the Northeast Pacific and the other in the Northwest Pacific, each with seasonal cohorts. Both stocks are targeted by commercial fishing fleets from China, Japan, and Taiwan. The variability in abundance for each stock has been studied independently, but a comparable analysis between the two stocks is lacking. The abundance trends for the two stocks were examined using catch data from the Taiwanese squid fishery between 1986 and 2006. A time- series of monthly catch per unit effort and three explanatory variables, sea surface temperature in the presumed hatching grounds, the Southern Oscillation Index, and the number of vessels, were analysed using dynamic factor analysis to quantify squid abundance. The optimal model contained one common trend and all three explanatory variables. The Northwest Pacific and Northeast Pacific stocks exhibited opposing trends in abundance, and the results suggest that large- scale environmental factors, rather than regional factors, are more critical in influencing the abundance of oceanic squid species.
KEYWORDS:
abundance; dynamic factor analysis; North Pacific; Ommastrephes bartramii; squid fishery dynamic factor-analysis; winter-spring cohort; sensed mesoscale oceanography; illex-argentinus cephalopoda; agricultural area adjacent; everglades-national-park; short-finned squid; time-series; environmental-influences; common trends

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(2010) Chen, M.L., Price, R.M., Yamashita, Y. and Jaffe, R. Comparative study of dissolved organic matter from groundwater and surface water in the Florida coastal Everglades using multi-dimensional spectrofluorometry combined with multivariate statistics. Applied Geochemistry 25(6), 872-880.

 

ABSTRACT
Dissolved organic matter (DOM) in groundwater and surface water samples from the Florida coastal Everglades were studied using excitation-emission matrix fluorescence modeled through parallel factor analysis (EEM-PARAFAC). DOM in both surface and groundwater from the eastern Everglades S332 basin reflected a terrestrial-derived fingerprint through dominantly higher abundances of humic-like PARAFAC components. In contrast, surface water DOM from northeastern Florida Bay featured a microbial-derived DOM signature based on the higher abundance of microbial humic-like and protein-like components consistent with its marine source. Surprisingly, groundwater DOM from northeastern Florida Bay reflected a terrestrial-derived source except for samples from central Florida Bay well, which mirrored a combination of terrestrial and marine end-member origin. Furthermore, surface water and groundwater displayed effects of different degradation pathways such as photodegradation and biodegradation as exemplified by two PARAFAC components seemingly indicative of such degradation processes. Finally, Principal Component Analysis of the EEM-PARAFAC data was able to distinguish and classify most of the samples according to DOM origins and degradation processes experienced, except for a small overlap of S332 surface water and groundwater, implying rather active surface-to-ground water interaction in some sites particularly during the rainy season. This study highlights that EEM-PARAFAC could be used successfully to trace and differentiate DOM from diverse sources across both horizontal and vertical flow profiles, and as such could be a convenient and useful tool for the better understanding of hydrological interactions and carbon biogeochemical cycling.
KEYWORDS:
excitation-emission matrix; parallel factor-analysis; fluorescence spectroscopy; chemical characteristics; humic substances; south florida; bay; mangrove; carbon; usa

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(2010) Dadone, L.I., Klaphake, E., Garner, M.M., Schwahn, D., Sigler, L., Trupkiewicz, J.G., Myers, G. and Barrie, M.T. Pituitary Cystadenoma, Enterolipidosis, and Cutaneous Mycosis in an Everglades Ratsnake (Elaphe Obsoleta Rossalleni). Journal of Zoo and Wildlife Medicine 41(3), 538-541.

 

ABSTRACT
An 11-yr-old captive-born male Everglades ratsnake (Elaphe obsoleta rosalleni) presented with dysecdysis, hyperkeratosis, and inappetance. Two skin biopsies demonstrated a diffuse hyperkeratosis with both a bacterial and fungal epidermitis. Fusarium oxysporum was cultured from both biopsies and considered an opportunistic infection rather than a primary pathogen. Medical management was unsuccessful, and the snake was euthanized. Histologic findings included a pituitary cystadenoma arising from the pars intermedia, severe intestinal lipidosis, generalized epidermal hyperkeratosis, and lesions consistent with sepsis. It is hypothesized that endocrine derangements from the pituitary tumor may have caused the skin and intestinal lesions.
KEYWORDS:
Cutaneous mycosis; Everglades ratsnake (Elaphe obsolete rossalleni); Fusarium oxysporum; intestinal lipidosis; pituitary cystadenoma

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(2010) Danalatos, N.G. and Archontoulis, S.V. Growth and biomass productivity of kenaf (Hibiscus cannabinus, L.) under different agricultural inputs and management practices in central Greece. Industrial Crops and Products 32(3), 231-240.

 

ABSTRACT
The growth and biomass productivity of kenaf (Hibiscus cannabinus, L.) cultivars Tainung 2 and Everglades 41 were determined under three irrigation applications (low: 25%, moderate: 50% and fully: 100% of maximum evapotranspiration; ETm), four nitrogen dressings (0, 50, 100 and 150 kg hat), two sowing dates, and two plant densities (20 and 30 pl m(-2)) in two field experiments carried out on an representative aquic soil of western Thessaly plain (central Greece), in the period 2003-2005. The results demonstrated a paramount effect of sowing time (and thus the availability of the vegetative growing period) on crop growth and biomass productivity; delayed sowings (after mid-May) may reduce biomass production by 38%. Irrigation water had a significant effect (P < 0.05) on growth indices and biomass productivity fluctuating upon flowering from 15.1 to 18.5 and to 20.3 t ha(-1) (3-year average values) for the low, moderate and fully irrigated plants, respectively. Stems are the economic yield comprising about 87% of the total biomass in all cases. The relatively small effect of 50% irrigation to biomass production was attributed to the increased soil moisture status of the studied (aquic) soil. Contrarily, N-fertilization in the studied range did not affect significantly growth and productivity due the high fertility status of the soil, while plant population in the study range had a minor effect (P > 0.05) on biomass accumulation. Cultivars performed similar growth rates (no significant differences), which under full water and nitrogen inputs reached maximum growth rates of 180-220 kg ha(-1) day(-1) which may serve as reference for the assessment of crop performance under production situations at hierarchically lower input and management levels for central Greek conditions.
KEYWORDS:
Kenaf; Sowing; Irrigation; Fertilization; Growth rates; Biomass production northern australia; simulation-model; tropical australia; sowing date; yield; nitrogen; cultivation; irrigation; water; crop

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(2010) de Andres, E.F., Tenorio, J.L. and Walter, I. Biomass production and nutrient concentration of kenaf grown on sewage sludge-amended soil. Spanish Journal of Agricultural Research 8(2), 472-480.

 

ABSTRACT
Due to increasingly strict control of wastewater treatment, the production of sewage sludge is surging and the problem of its disposal is therefore also growing. Recycling this waste as a fertilizer is an economically and environmentally attractive option. Determining the availability of macro- and micronutrients in these sludges is important if such wastes are to provide sufficient nutrients to crops while causing minimal environmental damage. A greenhouse study with two kenaf cultivars ('Everglades 41' and 'Tainung 2') was designed to evaluate the effects of sewage sludge processing mode on plant development, biomass yield, and nutrient availability. Two different processing modes of sludges (digested dewatered and pelletized-heat dried) applied at two rates, 10 and 20 Mg ha(-1) were compared with inorganic N and a zero-N control. Plant height, basal stems diameter and biomass production increased slightly with the sewage sludge treatments but in different manners depending on the kenaf cultivar in question. Both sludges were similar in their ability to supply N to the plants. Apparent N recovery and N fertilizer equivalent value were greater in the low dosage treatments. Of the two cultivars, 'Everglades 41' showed greater mean values for all the variables studied. No differences were found in leaf P, K, Ca, Mg contents among treatments. The Zn and Cu concentrations were the only trace elements that increased in the leaf tissues with sludge application, although the values recorded were well below critical environmental thresholds.
KEYWORDS:
biomass yield; digested dewatered sewage sludge; dried-pelletized sewage sludge; fertilizer value; Hibiscus cannabinus; nutrients; trace elements available nitrogen; trace-elements; dairy compost; tall fescue; biosolids; yield; recovery; accumulation; 1st-year; columns

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(2010) DeAngelis, D.L., Trexler, J.C., Cosner, C., Obaza, A. and Jopp, F. Fish population dynamics in a seasonally varying wetland.
Ecological Modelling 221(8), 1131-1137.

 

ABSTRACT
Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the 'reaction-diffusion' mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first-the 'refuge mechanism'-hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.
KEYWORDS:
Fish functional group; Wetland; Diffusion-reaction model; Ideal free distribution; Fish refugia ideal-free distribution; habitat structure; wading birds; stream fish; model; movement; everglades; patterns; availability; assemblages

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(2010) Deng, Y., Solo-Gabriele, H.M., Laas, M., Leonard, L., Childers, D.L., He, G.Q. and Engel, V. Impacts of hurricanes on surface water flow within a wetland. Journal of Hydrology 392(3-4), 164-173.

 

ABSTRACT
Between 2001 and 2005, seven category 3 or higher major hurricanes made landfall within the US. The hydrologic impacts of these distinct climatic phenomena frequently occurring in wetland watersheds, however, are not well understood. The focus of this study was to evaluate the impacts of hurricane wind and rainfall conditions on water velocity and water elevations within the study wetland, the Florida Ever-glades. Specifically water velocity data was measured near two tree islands (Gumbo Limbo (GL) and Satin Leaf (SL)) and wind speed, water elevation, and rainfall were obtained from nearby wind observation stations. During the direct impacts of the hurricanes (Hurricanes Katrina and Wilma), water speed, flow direction, and hydraulic gradients were altered, and the extent of variation was positively related to wind characteristics, with significant alterations in flow direction at depth during Hurricane Wilma due to higher wind speeds. After the direct impacts, the longer lasting effect of hurricanes (time scale of a few days) resulted in altered flow speeds that changed by 50% or less. These longer lasting changes in flow speeds may be due to the redistribution of emergent vegetation.
KEYWORDS:
Hurricane; Wetland; Water velocity; Wind velocity everglades national-park; subtropical wetland; coastal wetlands; lake okeechobee; florida; landscape; sediments; forest; mexico; storm

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(2010) Dobbs, G.R. Raising Cane in the 'Glades: The Global Sugar Trade and the Transformation of Florida - Book Review.
Geographical Research 48(4), 440-441.

 

ABSTRACT (none)
KEYWORDS:
early-20th-century; Everglades

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(2010) Duncan, B.W., Adrian, F.W. and Stolen, E.D. Isolating the lightning ignition regime from a contemporary background fire regime in east-central Florida, USA. Canadian Journal of Forest Research-Revue Canadienne De Recherche Forestiere 40(2), 286-297.

 

ABSTRACT
Anthropogenic influences have altered most lire regimes Fire management programs often try to mimic natural fire regimes to maintain fuels and sustain native fire-dependent species Lightning is the natural ignition source in Florida. substantiating the need for understanding lightning fire incidence Sixteen years of lightning data (1986-2003, excluding 1987 and 2002 due to missing data) from the NASA Cloud to Ground Lightning Surveillance System and fire ignition records were used to quantify the relationship between lightning incidence and ignitions on Kennedy Space Center, Merritt Island National Wildlife Refuge, and Cape Canaveral Air Force Station There were 230 lightning fires with an average of 14 ignitions per year, primarily in July. and only one winter ignition Precipitation Influenced the efficiency of lightning ignitions, particularly July precipitation We found that negative polarity strikes caused the majority of ignitions. Pine flat-woods was Ignited more frequently than expected given equal chance of ignition among landcover types About half (51%) of detected tires were instantaneous ignitions and the other 49% were delayed an average of 2 days This information is useful for paramaterizing fire regime models and for mimicking the natural fire regime through fire prescriptions on these properties and throughout the southeastern United States These methods may be useful in fire-maintained systems globally.
KEYWORDS:
contiguous united-states; forest-fires; availability data; landscape change; vegetation type; scrub; population; everglades; management; wildfire

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(2010) FDEP - Florida Department of Environmental Protection, Appendix 3A-1: Summary of Water Year 2009 Water Quality Monitoring Results. 4.

 

ABSTRACT (none)
https://my.sfwmd.gov/portal/page/portal/pg_grp_sfwmd_sfer/portlet_sfer/tab2236037/2010%20report/v1/appendices/v1_app3A-1.pdf

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(2010) Fisher, M.M. and Reddy, K.R. Estimating the Stability of Organic Phosphorus in Wetland Soils.
Soil Science Society of America Journal 74(4), 1398-1405.

 

ABSTRACT
The distribution of soil P among labile and nonlabile forms can be a major determinant of agricultural and natural ecosystem productivity. Determination of soil P pools is typically performed using operationally defined chemical fractionation methods. Most of the current fractionation techniques were developed for predominately mineral soils, thus they provide only limited information on organic P (P-o), particularly with respect to stability,. We hypothesized that the extent to which P could be extracted from organic soils, after exposure to hear, may be related to environmental recalcitrance. We investigated two thermal methods for characterizing P-o stability in organic wetland soils, an autoclave-based and a dry heat technique. Soils from two subtropical wetlands were collected to a depth of approximately 1 m. Autoclave-extractable P was determined by subjecting soils to 128 degrees C and 170 kPa for 90 min in an autoclave. A second set of samples was exposed to dry heat at temperatures of 160, 200, 260, 300, 360, and 550 degrees C. The results were compared with data from a conventional chemical P fractionation scheme. Phosphorus that could be extracted using the hot water technique declined with soil depth, representing 10 to 50% of total Pin surficial soils, to 5 to 10% at a depth of 60 cm. Microbial biomass P was correlated with hot water extractable P. and represented approximately 50% of the hot water extract. In the dry heat technique, increasing the extraction temperature resulted in significantly greater extraction of P-o. The 360 degrees C treatment was best able to distinguish between recalcitrant and labile P-o.
KEYWORDS:
nutrient accumulation; lake sediments; fractionation; everglades; phosphate; florida; rates

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(2010a) Florea, L.J. and McGee, D.K. Stable isotopic and geochemical variability within shallow groundwater beneath a hardwood hammock and surface water in an adjoining slough (Everglades National Park, Florida, USA). Isotopes in Environmental and Health Studies 46(2), 190-209.

 

ABSTRACT
CORRIGENDUM: Portions of the data used in this study were presented at the 14th Symposium of the Geology of the Bahamas and other Carbonate Terranes and the Geological Society of America Annual Meeting in 2008 and 2009, respectively. The authors prepared an extended paper for their conference proceedings volume. That paper was submitted in September of 2009 and published in June 2010. In early 2010, the authors prepared and submitted a more thorough treatment of their work to Isotopes in Environment and Health Studies (GIEH) for peer-review and distribution among the larger hydrologic and isotope communities. Subsequent review and revision resulted in the finalised manuscript. Although similar language is reflected in both articles, the authors intended the GIEH paper to be more international in scope. The Bahamas Proceedings article is structured more as a report of data collected from the Everglades ecosystem, whereas the GIEH article focusses more upon the theoretical and applied usage of stable isotopes in hydrologic and climate studies. The authors would like to acknowledge and cite the earlier version of the article published in the Proceedings of the 14th Symposium on the Geology of the Bahamas and other Carbonate Regions.
KEYWORDS:
isotopes, variability

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(2010b) Florea, L.J. and McGee, D.K. Stable isotopic and geochemical variability within shallow groundwater beneath a hardwood hammock and surface water in an adjoining slough (Everglades National Park, Florida, USA) (vol 46/2, pg 190, 2010). Isotopes in Environmental and Health Studies 46(3), 405-405.

 

ABSTRACT
Data from a 10-month monitoring study during 2007 in the Everglades ecosystem provide insight into the variation of delta O-18, delta D, and ion chemistry in surface water and shallow groundwater. Surface waters are sensitive to dilution from rainfall and input from external sources. Shallow groundwater, on the other hand, remains geochemically stable during the year. Surface water input from canals derived from draining agricultural areas to the north and east of the Everglades is evident in the ion data. delta O-18 and delta D values in shallow groundwater remain near the mean of -2.4 and -12%, respectively. O-18 and D values are enriched in surface water compared with shallow groundwater and fluctuate in sync with those measured in rainfall. The local meteoric water line (LMWL) for precipitation is in close agreement with the global meteoric water line; however, the local evaporation line (LEL) for surface water and shallow groundwater is delta D = 5.6 delta O-18 + 1.5, a sign that these waters have experienced evaporation. The intercept of the LMWL and LEL indicates that the primary recharge to the Everglades is tropical cyclones or fronts. delta deuterium to delta O-18 excess (D-ex values) generally reveal two moisture sources for precipitation, a maritime source during the fall and winter (D-ex > 10%) and a continental-influenced source (D-ex < 10%) in the spring and summer.
KEYWORDS:
isotope ecology; hydrogen-2; oxygen-18; Everglades National Park; USA; delta D to delta O-18 excess; Everglades agricultural area; mid-summer drought geiger climate classification; caribbean midsummer drought; interannual variability; eastern pacific; central-america; amazon basin; world map; precipitation; deuterium; rainfall

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(2010) Fujisaki, I., Pearlstine, L.G. and Mazzotti, F.J. Validation of daily surface water depth model of the Greater Everglades based on real-time stage monitoring and aerial ground elevation survey. Wetlands Ecology and Management 18(1), 17-26.

 

ABSTRACT
As part of the Everglades Depth Estimation Network (EDEN) project, this paper describes validation of raster-based daily surface water depth models of the Greater Everglades in Florida developed using real-time stage data and elevation data obtained from a survey with an aerial height finder. Daily median stage data obtained at over 200 locations were interpolated using the multiquadric radial basis function. Surface water depth was obtained by subtracting a digital elevation model from the interpolated stage raster. The model was validated with 751 independent field measurements of surface water depth between 1999 and 2004. Correlations between prediction error and both density of the monitoring gages and distance from a major linear geographic feature, such as a canal, were weak, suggesting that the error does not depend on these features. South Florida has distinct dry and wet seasons and the study area is dominated by sawgrass and wet prairie. Seasonality and ground vegetation type significantly affect prediction error. Correlation between observed and predicted water depth was high for all combination of season and vegetation type (0.83-0.96). Model validation using an equivalence test provided evidence of equivalence between predicted and observed water depths in dry season prairie-dominated and wet season sawgrass-dominated areas with the strict test and in dry season sawgrass-dominated areas with the liberal test, but not in wet season prairie-dominated areas. Equivalence between observed and predicted water depth for both dry season sawgrass- and wet season prairie-dominated areas were confirmed with the strict test after further model calibrations using linear regressions.
KEYWORDS:
Everglades; Digital elevation model; Multiquadric; Radial basis function; Vegetation map florida-everglades; equivalence tests; interpolation; management; equations; flow

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(2010) Gardner, L.M. and White, J.R. Denitrification Enzyme Activity as an Indicator of Nitrate Movement through a Diversion Wetland.
Soil Science Society of America Journal 74(3), 1037-1047.

 

ABSTRACT
The Davis Pond freshwater diversion is intended to help restore Louisiana's coastal wetlands by reintroducing Mississippi River water to Barataria Basin. We hypothesized that the high NO3- concentration (2.0 mg NO3-NL-1) of the Mississippi River water would control the rate of denitrification in the receiving marsh given that the soils are saturated, anaerobic, and contain high C. Therefore, areas of high denitrification enzyme activity (DEA) in the marsh would represent soils exposed to river NO3- and actively involved in denitrification. Data from 88 soil samples (0-10 cm) collected throughout the marsh revealed significantly higher rates of DEA in a 715-ha area adjacent to the diversion inflow. This area of generally high DEA contained >80% of all DEA observed while representing only 19% of the total marsh area at the low discharge rate of 39.5 m(3) s(-1). The area of high DEA coincided with the highest surface water NO3- and indicated that the marsh has a greater aerial capacity for NO3- removal than is utilized. A laboratory experiment suggested that soils loaded with external NO3- typically had higher DEA rates than soils receiving no added NO3-. The DEA was strongly dependent on soil depth (92% of DEA occurred at 0-5 cm) and internal N cycling was substantial in this wetland soils. This study demonstrates the applicability of using soil DEA to map where denitrification activity is greatest, the aerial extent of soils involved in denitrification, and the general flow path of introduced nutrients in large wetlands where NO3- is the limiting factor for denitrification.
KEYWORDS:
gulf-of-mexico; organic nitrogen mineralization; mississippi river water; sea-level rise; fresh-water; extraction method; chloroform fumigation; everglades soils; louisiana; sediments

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(2010) Giebel, B.M., Swart, P.K. and Riemer, D.D. delta C-13 Stable Isotope Analysis of Atmospheric Oxygenated Volatile Organic Compounds by Gas Chromatography-Isotope Ratio Mass Spectrometry. Analytical Chemistry 82(16), 6797-6806.

 

ABSTRACT
We present a new method for analyzing the delta C-13 isotopic composition of several oxygenated volatile organic compounds (OVOCs) from direct sources and ambient atmospheric samples. Guided by the requirements for analysis of trace components in air, a gas chromatograph isotope ratio mass spectrometer (GC-IRMS) system was developed with the goal of increasing sensitivity, reducing dead-volume and peak band broadening, optimizing combustion and water removal, and decreasing the split ratio to the isotope ratio mass spectrometer (IRMS). The technique relies on a two-stage preconcentration system, a low-volume capillary reactor and water trap, and a balanced reference gas delivery system. The instrument's measurement precision is 0.6 to 2.9 parts per thousand (1 sigma), and results indicate that negligible sample fractionation occurs during gas sampling. Measured delta C-13 values have a minor dependence on sample size; linearity for acetone was 0.06 parts per thousand ng C-1 and was best over 1-10 ng C. Sensitivity is similar to 10 times greater than similar instrumentation designs, incorporates the use of a diluted working reference gas (0.1% CO2), and requires collection of >0.7 ng C to produce accurate and precise results. With this detection limit, a 1.0 L sample of ambient air provides sufficient carbon for isotopic analysis. Emissions from vegetation and vehicle exhaust are compared and show clear differences in isotopic signatures. Ambient samples collected in metropolitan Miami and the Everglades National Park can be differentiated and reflect multiple sources and sinks affecting a single sampling location. Vehicle exhaust emissions of ethanol, and those collected in metropolitan Miami, have anomalously enriched delta C-13 values ranging from -5.0 to -17.2 parts per thousand; we attribute this result to ethanol's origin from corn and use as an additive in automotive fuels.
KEYWORDS:
nonmethane hydrocarbons; acetone; acetaldehyde; troposphere; emissions; pacific; budget; air; derivatization; formaldehyde

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(2010) Glaz, B. and Morris, D.R. Sugarcane Responses to Water-Table Depth and Periodic Flood. Agronomy Journal 102(2), 372-380.

 

ABSTRACT
Sugarcane (Saccharum spp.) is exposed to periodic floods and shallow water tables in Florida due to practices that reduce P discharge to the Everglades. This study examined the yields and juice quality of four sugarcane cultivars (CP 88-1762, Cl 89-2143, CP 89-2376, and CP 96-1252) maintained at constant water-table depths near 20 (20CWT) and 45 cm (45CWT) and with periodic summer flooding. Prescribed lysimeters were flooded for the first 7 d of five, five, and four 21-d cycles in 2005 (plant-cane crop), 2006 (first-ratoon crop), and 2007 (second-ratoon crop), respectively. These treatments generally remained flooded during the next 7 d while they received no irrigation or drainage, and were drained to 20 (20FWT) or 45 cm (45FWT) for the final 7 d of each cycle. Water treatment affected CRS only in the plant-cane crop, where 45CWT had lower CRS than 20CWT, 20FWT, and 45FWT. Yields of cane and sucrose of CP 89-2143 were least affected by water treatments. Reductions in cane and sucrose yields at a 20 compared with a 45 cm water-table depth were common for the other three cultivars, but yields under the 20CWT vs. 20FWT or 45CWT vs. 45FWT treatments were generally similar. These results suggest that sugarcane roots function well in flood for up to 14 d, but do not grow well into saturated soil. This provides new options for sustaining high yields of sugarcane exposed to shallow water tables and floods; verification of root responses could enhance strategies to sustain yields while reducing P discharge.
KEYWORDS:
everglades agricultural area; gas-transport; registration; hypoxia

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(2010) Gondwe, B.R.N., Hong, S.H., Wdowinski, S. and Bauer-Gottwein, P. Hydrologic Dynamics of the Ground-Water-Dependent Sian Ka'an Wetlands, Mexico, Derived from InSAR and SAR Data. Wetlands 30(1), 1-13.

 

ABSTRACT
The 5,280 km(2) Sian Ka'an Biosphere Reserve includes pristine wetlands fed by ground water from the karst aquifer of the Yucatan Peninsula, Mexico. The inflow through underground karst structures is hard to observe making it difficult to understand, quantify, and predict the wetland dynamics. Remotely sensed Synthetic Aperture Radar (SAR) amplitude and phase observations offer new opportunities to obtain information on hydrologic dynamics useful for wetland management. Backscatter amplitude of SAR data can be used to map flooding extent. Interferometric processing of the backscattered SAR phase data (InSAR) produces temporal phase-changes that can be related to relative water level changes in vegetated wetlands. We used 56 RADARSAT-1 SAR acquisitions to calculate 38 interferograms and 13 flooding maps with 24 day and 48 day time intervals covering July 2006 to March 2008. Flooding extent varied between 1,067 km2 and 2,588 km(2) during the study period, and main water input was seen to take place in sloughs during October December. We propose that main water input areas are associated with water-filled faults that transport ground water from the catchment to the wetlands. InSAR and Landsat data revealed local-scale water divides and surface water flow directions within the wetlands.
KEYWORDS:
Hydrology; Remote sensing; Surface water; Synthetic aperture radar interferometry; Yucatan Peninsula synthetic-aperture radar; everglades national-park; level changes; yucatan peninsula; biosphere-reserve; quintana-roo; interferometry; surface; inundation; vegetation

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(2010) Hackley, P.C., SanFilipo, J.R., Azizi, G.P., Davis, P.A. and Starratt, S.W. Organic petrology of subbituminous carbonaceous shale samples from Chalaw, Kabul Province, Afghanistan: Considerations for paleoenvironment and energy resource potential. International Journal of Coal Geology 81(4), 269-280.

 

ABSTRACT
Neogene (?) subbituminous carbonaceous shale deposits from Chalaw, Afghanistan, were investigated through organic petrology techniques and standard coal analyses to determine paleoenvironment and potential for resource utilization. The Chalaw deposit, approximately 30 km southeast of Kabul, currently is exploited for brick making and domestic heating and cooking. Three multiple-bench channel samples of the mined bed at Chalaw were collected and evaluated. The presence of significant huminite (ranging from 0.2 to 59.0 vol.%, mineral-inclusive basis) is suggestive of a terrestrial lignin-rich precursor plant material. Measured reflectance values of 0.38-0.55% indicate subbituminous rank. This rank suggests burial depths of approximately 1500 m and maximum temperatures of approximately 50 C. Structured liptinite macerals generally are absent except for some fluorescing morphologies interpreted to be poorly-preserved root cork suberinite. Sponge spicule bioliths including gemmoscleres and megascleres are common. These petrographic observations, in addition to high mineral matter content (33 to >95 vol.%), medium to high sulfur content (2.1-11.5 wt.%, dry basis; db), and the presence of common gastropod? shell fragments and an aragonite-needle chalk bed are consistent with, but not directly indicative of, a marginal marine or estuarine mangrove depositional environment. However, additional data are necessary to confirm this hypothesis and deposition in a freshwater environment cannot be ruled out at this time. Commercial-scale development and utilization of the Chalaw deposit as a thermal fuel resource may be possible using a fluidized bed combustion system which could accept the low-quality mine product currently produced. Samples examined herein contain high-ash yield (45-90 wt.%, db), high total moisture content (1739 wt.%), low calorific value (980-6860 Btu/lb, m.mmf), and have poor agglomerating properties (FSI = 0), consistent with fuels utilized in fluidized bed combustors. However, delineation of the extent of the deposit through field investigation will be necessary to make a quantified resource estimate for mine planning.
KEYWORDS:
Afghanistan; Coal utilization; Carbonaceous shale; Organic petrology; Paleoenvironment; Subbituminous rank florida everglades; peat; coal; swamp; degradation; environment; ophiolites; california; paleocene; mangroves

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(2010a) Hagerthey, S.E., Cole, J.J. and Kilbane, D. Aquatic metabolism in the Everglades: Dominance of water column heterotrophy.
Limnology and Oceanography 55(2), 653-666.

 

ABSTRACT
Using high-frequency measurements of free water dissolved oxygen (O-2), we assessed gross primary production (GPP), respiration (R), and net aquatic production (NAP) in the shallow-water Everglades peatland between 1996 and 2005. We distinguish NAP from net ecosystem production since the boundary for shallow aquatic ecosystems may include aboveground GPP of wetland biota. Metabolism was estimated for 68 sites distributed among nine habitats and yielded 1085 5-d deployments or 5425 site-days. Habitats differed in vegetation composition, trophic status, and hydrology. Systemwide O-2 averaged 3.8 +/- 2.2 mg L-1 (mean +/- SD), or 49% +/- 30% of atmospheric saturation. GPP, R, and NAP averaged 103 +/- 76, 220 +/- 79, and 2117 +/- 65 mmol O-2 m(-2) d(-1), respectively. Metabolism was greater during the summer-wet season when greater irradiance, temperature, and material flux stimulate primary production and decomposition. Paradoxically, GPP was inversely related to total phosphorus (TP), with oligotrophic (TP < 7 mg L-1) open-water habitats dominated by periphyton having the highest and eutrophic (TP > 35 mg L-1) habitats with dense emergent macrophytes the lowest rates. R was greatest for moderately enriched (TP = 15 mg L-1) open-water habitats with floating macrophytes. The prevalence of net heterotrophy, 96% of the 1085 NAP estimates, reveals the importance of aboveground biota in regulating aquatic metabolism and O-2 dynamics in shallow ecosystems. R is not only regulated by the influx of aboveground autochthonous carbon but also by aquatic GPP. Carbon turnover is greater in habitats where O-2 production by aquatic vegetation enables aerobic respiration. Conversely, water-column GPP is suppressed by dense emergent macrophytes, which limits O-2 availability, favors anaerobic respiration, and reduces carbon turnover.
KEYWORDS:
dissolved organic-carbon; florida everglades; northern everglades; community metabolism; spatial-distribution; soil properties; nutrient; wetland; oxygen; ecosystem

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(2010b) Hagerthey, S.E., Newman, S. and Gottlieb, A. Freshwater salinity and algal ecology: linking Everglades periphyton responses to physiological mechanisms. Journal of Phycology

 

ABSTRACT (none)
KEYWORDS:

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(2010) Haitjema, H., Gusyev, M. and Wilsnack, M. Truncating Cross-Sectional Groundwater Models under Wetlands.
Journal of Hydrologic Engineering 15(7), 537-543.

 

ABSTRACT
Cross-sectional models, which represent two-dimensional flow in the vertical plane, tend to have problematic aspect ratios since the aquifer thickness is often small compared to the lateral extent of the flow domain. For that reason, the model domain is usually limited to the immediate area of interest, for instance the aquifer section underneath a dam. We propose a Cauchy boundary condition to represent flow from remote wetlands that are left out of the truncated model. The resistance to flow inherent to such a boundary depends on the aquifer properties and the resistance to flow through the wetland bottom. While the Cauchy boundary condition is based on the Dupuit-Forchheimer approximation to flow underneath the remote wetlands, the error appears to be negligible (less than 0.6%) for most practical cases, including flow in stratified aquifers. For the case of multiple aquifers underneath the wetlands, the total flow in the truncated model can be a few percent in error, which is typically acceptable for most engineering applications. The approach is illustrated with an application near a levee-borrow canal setting in the Florida Everglades.
KEYWORDS:
Groundwater flow modeling; Two-dimensional flow; Flow in the vertical plane; Wetlands

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(2010) Hall, S.J. and Zedler, J.B. Constraints on Sedge Meadow Self-Restoration in Urban Wetlands. Restoration Ecology 18(5), 671-680.

 

ABSTRACT
Invasive plants and urban run-off constrain efforts to restore sedge meadow wetlands. We asked if native graminoids can self-restore following the removal of Typha x glauca (hybrid cattail), and if not, what limits their recovery? After we harvested Typha and depleted its rhizome starch reserves, Carex spp. expanded vegetatively (approximately 1 m over 2 years) but not by recruiting seedlings. A seedling emergence experiment showed that seed banks were depleted where Typha had eliminated the sedge meadow over a decade ago (based on aerial photo analysis). Carex seedling emergence was 75-90% lower where Carex was absent than where it remained in the plant community, and at least 17 species that were abundant 30 years ago were absent from the seed bank and extant vegetation. By varying hydroperiod, we showed that prolonged flooding prevented emergence of Carex seedlings and that a fluctuating hydroperiod reduced emergence and ultimately killed all Carex seedlings. In contrast, Typha seedlings emerged and survived regardless of hydroperiod. Thus, slow vegetative expansion by Carex, depauperate seed banks, and altered hydroperiods all constrain self-restoration. To compensate for multiple constraints on self-restoration, we recommend a long-term management approach that capitalizes on flooding and the capacity of Carex spp. to regrow vegetatively. We suggest annually harvesting swaths of Typha at the edges of clones, before or during flood events, to allow gradual, vegetative self-restoration of Carex spp.
KEYWORDS:
Carex; hydroperiod; seed bank; self-design; Typha x glauca typha-x-glauca; fresh-water wetland; seed banks; vegetation; carex; germination; latifolia; marsh; everglades; dominance

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(2010) Han, Y., Wang, Y.Q. and Zhao, Y.S. Estimating Soil Moisture Conditions of the Greater Changbai Mountains by Land Surface Temperature and NDVI. IEEE Transactions on Geoscience and Remote Sensing 48(6), 2509-2515.

 

ABSTRACT
Soil moisture is an important indicator of the land surface environment. The combination of land surface temperature (LST) and normalized difference vegetation index (NDVI) could enhance the ability of extracting information on soil moisture conditions. In this study, we employed multitemporal Moderate Resolution Imaging Spectroradiometer (MODIS) data products of LST, NDVI, and land cover types to obtain the information about soil moisture for the greater Changbai Mountains. We selected nine time periods in 2007 for inversion of the soil moisture conditions and focused the analysis on four critical time periods. According to the spatial pattern of the LST and NDVI, we established the "wet-edge" and "dry-edge" equations and determined the relative parameters. We obtained the temperature-vegetation dryness index (TVDI) using the wet-edge and dry-edge relationships to reveal temporal changes of the land surface soil moisture conditions of the study area. We also analyzed the relationship between different land cover types in five TVDI classes. This paper demonstrates that TVDI is an effective indicator to detect soil moisture status in the greater Changbai Mountains region.
KEYWORDS:

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(2010) Hanan, E.J. and Ross, M.S. Across-scale patterning of plant-soil-water interactions surrounding tree islands in Southern Everglades landscapes. Landscape Ecology 25(3), 463-476.

 

ABSTRACT
The freshwater Everglades is a complex system containing thousands of tree islands embedded within a marsh-grassland matrix. The tree island-marsh mosaic is shaped and maintained by hydrologic, edaphic and biological mechanisms that interact across multiple scales. Preserving tree islands requires a more integrated understanding of how scale-dependent phenomena interact in the larger freshwater system. The hierarchical patch dynamics paradigm provides a conceptual framework for exploring multi-scale interactions within complex systems. We used a three-tiered approach to examine the spatial variability and patterning of nutrients in relation to site parameters within and between two hydrologically defined Everglades landscapes: the freshwater Marl Prairie and the Ridge and Slough. Results were scale-dependent and complexly interrelated. Total carbon and nitrogen patterning were correlated with organic matter accumulation, driven by hydrologic conditions at the system scale. Total and bioavailable phosphorus were most strongly related to woody plant patterning within landscapes, and were found to be 3 to 11 times more concentrated in tree island soils compared to surrounding marshes. Below canopy resource islands in the slough were elongated in a downstream direction, indicating soil resource directional drift. Combined multi-scale results suggest that hydrology plays a significant role in landscape patterning and also the development and maintenance of tree islands. Once developed, tree islands appear to exert influence over the spatial distribution of nutrients, which can reciprocally affect other ecological processes.
KEYWORDS:
Hierarchical patch dynamics paradigm; Hierarchy theory; Soil heterogeneity; Resource islands; Peat accumulation; Phosphorus redistribution; Ridge and Slough; Freshwater marl prairies; Florida wetlands; Hydrologic management hierarchical patch dynamics; florida everglades; nutrient dynamics; phosphorus; vegetation; floodplain; carbonate; botswana; fan

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(2010) Hanan, E.J., Ross, M.S., Ruiz, P.L. and Sah, J.P. Multi-Scaled Grassland-Woody Plant Dynamics in the Heterogeneous Marl Prairies of the Southern Everglades. Ecosystems 13(8), 1256-1274.

 

ABSTRACT
The Everglades freshwater marl prairie is a dynamic and spatially heterogeneous landscape, containing thousands of tree islands nested within a marsh matrix. Spatial processes underlie population and community dynamics across the mosaic, especially the balance between woody and graminoid components, and landscape patterns reflect interactions among multiple biotic and abiotic drivers. To better understand these complex, multi-scaled relationships we employed a three-tiered hierarchical design to investigate the effects of seed source, hydrology, and more indirectly fire on the establishment of new woody recruits in the marsh, and to assess current tree island patterning across the landscape. Our analyses were conducted at the ground level at two scales, which we term the micro- and meso-scapes, and results were related to remotely detected tree island distributions assessed in the broader landscape, that is, the macro-scape. Seed source and hydrologic effects on recruitment in the micro- and meso-scapes were analyzed via logistic regression, and spatial aggregation in the macro-scape was evaluated using a grid-based univariate O-ring function. Results varied among regions and scales but several general trends were observed. The patterning of adult populations was the strongest driver of recruitment in the micro- and meso-scape prairies, with recruits frequently aggregating around adults or tree islands. However in the macro-scape biologically associated (second order) aggregation was rare, suggesting that emergent woody patches are heavily controlled by underlying physical and environmental factors such as topography, hydrology, and fire.
KEYWORDS:
woody plant invasion; recruitment; dispersal; hierarchical patch dynamics; univariate grid-based O-ring function; spatial patterning; community and landscape structure; shifting boundaries; tree islands; Cape Sable seaside sparrow habitat sable seaside-sparrow; point pattern-analysis; seed dispersal; patch-dynamics; tree islands; fire; recruitment; landscape; ecology; forest

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(2010) Hanlon, E.A., Fan, X.H., Gu, B., Migliaccio, K.W., Li, Y.C. and Dreschel, T.W. Water Quality Trends at Inflows to Everglades National Park, 1977-2005. Journal of Environmental Quality 39(5), 1724-1733.

 

ABSTRACT
Restoration of the Florida Everglades is important for the health of the natural system, including both the "River of Grass" and its downstream estuaries. Water quality improvement is one indicator of successful restoration in this complex ecosystem. Using the period of record of 1977 through 2005, we evaluated data from seven inflow sites to the Everglades National Park (ENP) for temporal trends of various forms of phosphorus (P) and nitrogen (N) and analyzed them using principal component analysis and factor analysis without flow adjustments. Locally estimated scatter plot smoothing (LOESS) trend lines identified two inflection points (three time periods) of changing trend in total P (TP) concentration at the seven sites. Results indicated that overall water quality in ENP inflow improved from 1977 to 2005, with significant downward trends in TP concentration. The overall trend of TP is probably mediated by hydrology, which is evident by a negative relationship between flow and annual average TP concentration at the majority of stations within the available data, although additional changes in vegetation due to hydroperiod may have some effects. Total N (TN), total Kjeldahl N, and total organic N concentrations also generally decreased at inflow sites. Water quality standards for TP, TN, and NH4+-N were exceeded at selected sites during the study period. Principle component analysis and factor analysis detected a grouping of sampling sites related to the water delivery system that could be used as indicators to better manage monitoring resources. Study results suggest that water quality data analyses could provide additional insight into the success of a restoration management plan and on how monitoring may be modified for more efficient use of resources.
KEYWORDS:
river; restoration; management; florida

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(2010) Harris, W.G., Chrysostome, M., Obreza, T.A. and Nair, V.D. Soil Properties Pertinent to Horticulture in Florida. Horttechnology 20(1), 10-18.

 

ABSTRACT
Horticulture is an important industry in Florida despite formidable soil limitations. Favorable climate often makes the expense of overcoming these limitations economically feasible. Challenges arise from high water tables and/or sandy textures, both of which limit plant-available water and nutrient retention. High water tables of flatwoods (Spodosols) and marshes (Everglades Histosols) restrict root proliferation and commonly require artificial drainage. Upper zones of these soils are dominated by uncoated sand (Spodosols) or organic matter (Histosols) that has minimal sorption capacity for phosphorus (P) such that its transport poses an environmental risk without careful management. Nitrogen can be lost via denitrification under prolonged near-surface water saturation. At the other extreme but also prevalent in Florida are excessively well-drained sandy "sandhills" soils with limited water and nutrient retention. Nitrogen leaching from the latter soils can result in nitrate contamination in groundwater. Soil morphology is an important consideration in gauging nutrient and moisture retention. For example, each is enhanced by the presence of sand-grain coatings. Some amendments show promise in reducing P and moisture loss from sandy soils. Precarious balance between horticultural production and environmental risks for Florida soils has spurred development of approaches providing for a more accurate determination of the safe soil P storage capacity. Testing and refinement of these approaches are needed.
KEYWORDS:
nutrients; water; nitrogen; phosphorus water-treatment residuals; phosphorus retention capacity; management-practices; leaching loss; sandy soils; table; irrigation; everglades; spodosols; manure

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(2010) Hayes-Conroy, A. Raising Cane in the 'Glades: The Global Sugar Trade and the Transformation of Florida.
Annals of the Association of American Geographers
100(2), 483-485.

 

ABSTRACT
KEYWORDS:
Everglades; Florida; historical geography; political economy; sugar cane; REVIEW

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(2010) He, G., Engel, V., Leonard, L., Croft, A., Childers, D., Laas, M., Deng, Y. and Solo-Gabriele, H.M. Factors Controlling Surface Water Flow in a Low-gradient Subtropical Wetland. Wetlands 30(2), 275-286.

 

ABSTRACT
Surface water flow patterns in wetlands play a role in shaping substrates, biogeochemical cycling, and ecosystem characteristics. This paper focuses on the factors controlling flow across a large, shallow gradient subtropical wetland (Shark River Slough in Everglades National Park, USA), which displays vegetative patterning indicative of overland flow. Between July 2003 and December 2007, flow speeds at five sites were very low (<3 cm s(-1)), and exhibited seasonal fluctuations that were correlated with seasonal changes in water depth but also showed distinctive deviations. Stepwise linear regression showed that upstream gate discharges, local stage gradients, and stage together explained 50 to 90% of the variance in flow speed at four of the five sites and only 10% at one site located close to a levee-canal combination. Two non-linear, semi-empirical expressions relating flow speeds to the local hydraulic gradient, water depths, and vegetative resistance accounted for 70% of the variance in our measured speed. The data suggest local-scale factors such as channel morphology, vegetation density, and groundwater exchanges must be considered along with landscape position and basin-scale geomorphology when examining the interactions between flow and community characteristics in low-gradient wetlands such as the Everglades.
KEYWORDS:
Florida Everglades; Flow resistance; Restoration; Water speed; Water velocity through emergent vegetation; everglades national-park; phosphorus retention; submerged vegetation; florida everglades; landscape models; resistance; slough; coefficients; patterns

top    VID (2010) Hearn, P.P., Strong, D., Swain, E., Pearlstine, L., Claggett, and Donato, D. The IMMAGE Project - Internet-based Modeling, Mapping, and Analysis for the Greater Everglades. GEER'10 Conference, Naples, FL, July 2010 (slide show and audio - VID).
ABSTRACT
Recent analyses using current projections of sea level rise and LiDAR data for the eastern portions of Miami-Dade County suggest that coastal areas in South Florida will be subjected to the degradation of coastal habitats, contamination of municipal water supplies by the intrusion of salt water into coastal aquifers, alteration of ground water flow patterns, and increased risk of surgerelated flooding and wind damage from coastal storms. It is critical that water resource planners, park managers and municipal authorities have the best tools to assess the societal risks and economic impacts that these adverse environmental changes could have on coastal communities, protected lands, and the region as a whole. In evaluating and preparing for possible outcomes, alternative climate and land use scenarios are needed to evaluate the impacts of sea level rise and severe storms on existing and future land portfolios and social infrastructure. It is critical that these scenarios be based upon the best-available monitoring data and numerical flow models, rather than relying solely on static representations of sea level rise based on elevation data. An impressive body of work has been generated in the last several years with numerical models to forecast the impact of sea level rise on salt water intrusion, inland flooding, surge from coastal storms, and the resulting impact on the suitability of habitat for key species in the Greater Everglades. However, the usefulness of many models is constrained by the need to run them offline on dedicated workstations, lengthy run times, and the need for post-run processing and integration of results with other data.
The IMMAGE project is intended to enhance the usability of and broaden the user community of four key models by creating a GIS-based web interface for each model capable of serving model output to, and consuming output from other web-based applications. By running computationallyintensive models in advance and storing output in a server-side database, users are able to select from broad range of input parameters and obtain results online without excessive wait times. IMMAGE will develop interfaces for the following four models: 1) The BIscayne SouthEastern Coastal Transport (BISECT) model, a coupled ground and surface water model developed by Eric Swain and others at the U.S. Geological Survey's Florida Water Science Center, 2) Selected habitat distribution models, which utilize output from BISECT, developed by Leonard Pearlstine and others at the Everglades National Park, 3) The National Land Change Community Model, being developed by modelers within and outside the USGS, with contributions from Peter Claggett and David Donato of the USGS Eastern Geographic Science Center, and 4) the Sea, Lake and Overland Surges from Hurricanes (SLOSH) model developed by the National Oceanic and Atmospheric Administration' National Hurricane Center.
Contact Information: Paul P. Hearn, Eastern Geographic Science Center, U.S. Geological Survey, Reston, VA 20192, Phone: 703-648-6287, Fax: 703-648-4603, Email: phearn@usgs.gov

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(2010a) Herring, G., Ackerman, J.T. and Eagles-Smith, C.A. Embryo Malposition as a Potential Mechanism for Mercury-Induced Hatching Failure in Bird Eggs. Environmental Toxicology and Chemistry 29(8), 1788-1794.

 

ABSTRACT
We examined the prevalence of embryo malpositions and deformities in relation to total mercury (THg) and selenium (Se) concentrations in American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster's tern (Sterna forsteri) eggs in San Francisco Bay (CA, USA) during 2005 to 2007. Overall, 11% of embryos were malpositioned in eggs >= 18 d of age (n = 282) and 2% of embryos were deformed in eggs >= 13 d of age (n = 470). Considering only those eggs that failed to hatch (n = 62), malpositions occurred in 24% of eggs >= 18 d of age and deformities occurred in 7% of eggs >= 13 d of age. The probability of an embryo being malpositioned increased with egg THg concentrations in Forster's terns, but not in avocets or stilts. The probability of embryo deformity was not related to egg THg concentrations in any species. Using a reduced dataset with both Se and THg concentrations measured in eggs (n = 87), we found no interaction between Se and THg on the probability of an embryo being malpositioned or deformed. Results of the present study indicate that embryo malpositions were prevalent in waterbird eggs that failed to hatch and the likelihood of an embryo being malpositioned increased with egg THg concentrations in Forster's terns. We hypothesize that malpositioning of avian embryos may be one reason for mercury-related hatching failure that occurs late in incubation, but further research is needed to elucidate this potential mechanism. Environ. Toxicol. Chem. 2010;29:1788-1794. (C) 2010 SETAC
KEYWORDS:
Embryo deformity; Embryo malposition; Mercury; San Francisco Bay; Selenium san-francisco bay; double-crested cormorants; ibises eudocimus-albus; phalacrocorax-auritus; methyl mercury; great-lakes; dietary methylmercury; florida everglades; forsters terns; aquatic birds

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(2010b) Herring, G., Gawlik, D.E., Cook, M.I. and Beerens, J.M. Sensitivity of Nesting Great Egrets (Ardea Alba) and White Ibises (Eudocimus albus) to Reduced Prey Availability. Auk 127(3), 660-670.

 

ABSTRACT
Life-history theory suggests that long-lived bird species will adjust their nesting effort according to current conditions to balance the costs and benefits of current reproduction with their long-term needs for survival and future reproduction. However, responses to the same habitat conditions may differ between species, even within the same ecosystem, to produce different nesting and population patterns. We examined differences in the nesting ecology of two sympatric wading species, Great Egret (Ardea alba) and White Ibis (Eudocimus albus), between years with high (2006) and below-average (2007) prey availability in the Florida Everglades. Clutch size of White Ibises decreased by similar to 19% from 2006 to 2007, whereas Great Egret clutch size remained constant. Model selection identified rain, water depth, Julian date, year, and prey biomass as parameters that most influenced daily survival rates (DSR) of White Ibis nests, whereas nest stage, region, Julian date, water depth, and the quadratic form of water recession rate most influenced Great Egret nest DSR. Daily survival for both Great Egret and Whites Ibis nests was higher in 2006 (DSR = 0.992 and 0.999, respectively) than in 2007 (DSR = 0.981 and 0.979). Our results support the hypothesis that prey availability and hydrological factors play crucial roles in regulating populations of wading birds in the Florida Everglades. Results also demonstrated that White Ibis reproduction was more sensitive to changes in hydrological conditions and prey availability than Great Egret reproduction.
KEYWORDS:
Ardea alba; clutch size; Eudocimus albus; Florida Everglades; Great Egret; nesting ecology; nest survival; White Ibis wading birds; florida everglades; reproductive phases; brood reduction; breeding birds; food; population; patterns; history; success

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(2010) Hickey, T.D., Hine, A.C., Shinn, E.A., Kruse, S.E. and Poore, R.Z. Pleistocene Carbonate Stratigraphy of South Florida: Evidence for High-Frequency Sea-Level Cyclicity. Journal of Coastal Research 26(4), 605-614.

 

ABSTRACT
Pleistocene carbonates of south Florida and islands of the Florida Keys are currently divided into five marine sequences designated, from oldest to youngest, the Q1-Q5 units. The units include a mosaic of freshwater and shallow marine deposits that accumulated on the Florida platform during high sea-level stands. The units are separated by regional-scale subaerial-exposure surfaces that formed during glacioeustatic lowstands. Analyses of cores recovered at Grossman Ridge Rock Reef and Joe Rae Rock Reef in the Florida Everglades reveal additional subaerial-exposure surfaces that are used to delineate subdivisions within units Q1 (Q1a-Q1b), Q2 (Q2a-Q2d), and Q4 (Q4a-Q4b). Units Q1-Q5 preserve evidence of at least 10 separate sea-level highstands, rather than 5 as indicated by previous studies. Compilation of available uranium-series dates on corals recovered from the Florida Keys indicates that the Q4 unit accreted during sea-level maxima associated with marine oxygen-isotope Stage 9 (Q4a) and isotope Stage 7 (Q4b). The Q5 unit formed during isotope Stage 5. No reliable dates are available for units Q1-Q3. We infer that unit Q3 was formed during the extended sea-level highstand of isotope Stage 11 and that units Q2 and Q1 predate isotope Stage 11
KEYWORDS:
South Florida chronostratigraphy; South Florida lithostratigraphy; paleodepositional environments; carbonate accumulation; soilstone crusts; sea-level cyclicity; Pleistocene accumulation chronology key largo limestone; corals; reefs; bermuda; geology; oolites; crusts; margin; origin; shelf

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(2010a) Hong, S.H., Wdowinski, S. and Kim, S.W. Evaluation of TerraSAR-X Observations for Wetland InSAR Application.
IEEE Transactions on Geoscience and Remote Sensing 48(2), 864-873.

 

ABSTRACT
This paper assesses the potential of using space-borne X-band synthetic aperture radar (SAR) data for monitoring water-level changes over wetlands. Our analysis is based on three sets of TerraSAR-X (TSX) observations acquired over South Florida's Everglades wetlands during an eight-month period in 2008. The first set was acquired in single HH polarization stripmap mode over our northern study area, consisting of managed wetlands and urban environments. The second set was acquired in dual-polarization stripmap mode over the western half of the same area, consisting mostly of managed wetlands. The third set was also acquired with dual-polarization stripmap mode over our southern study area, consisting of natural flow fresh-and salt-water wetlands in the southern Everglades. The first data set was used for a proof-of-concept study to verify that X-band data can generate coherent interferograms in wetland areas. Interferometric processing of this data set shows a high level of coherence (> 0.35) over both wetland and urban regions, maintaining interferometric phase in all three interferograms spanning 11 days. Surprisingly, phase is maintained over some of the wetlands even for interferograms spanning 33 days. The other two data sets were used to evaluate interferometric coherence of all four polarization modes and to determine dominant scattering mechanism in each wetland environment. Our results show high coherence values (> 0.4) in all polarization modes, with highest values in HH, then VV, and lowest in HV or VH. Interferograms calculated from multipolarization data show very similar fringe patterns regardless of the polarization type, suggesting that the phase information in all polarization data reflects water-level changes in wetlands and that volume scattering may be less important than commonly believed. We also used the two multipolarization data sets to conduct the Pauli decomposition, finding a strong dependence of scattering mechanism on vegetation type. The high interferometric coherence level of all polarization data suggests that a significant part of the X-band scattered signal interacts with lower sections of the vegetation (trunks and branches), because scattering from wind-affected canopies cannot support such a high coherence level. The high spatial resolution of TSX, combined with its 11-day repeat orbit, makes this X-band sensor surprisingly suitable for wetland interferometric SAR applications.
KEYWORDS:
Coherence; interferometric SAR; TerraSAR-X; the Evergaldes; wetlands; X-band water-level changes; radar; interferometry; forests

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(2010b) Hong, S.H., Wdowinski, S., Kim, S.W. and Won, J.S. Multi-temporal monitoring of wetland water levels in the Florida Everglades using interferometric synthetic aperture radar (InSAR). Remote Sensing of Environment 114(11), 2436-2447.

 

ABSTRACT
Interferometric synthetic aperture radar (InSAR) techniques can successfully detect phase variations related to the water level changes in wetlands and produce spatially detailed high-resolution maps of water level changes. Despite the vast details, the usefulness of the wetland InSAR observations is rather limited, because hydrologists and water resources managers need information on absolute water level values and not on relative water level changes. We present an InSAR technique called Small Temporal Baseline Subset (STBAS) for monitoring absolute water level time series using radar interferograms acquired successively over wetlands. The method uses stage (water level) observation for calibrating the relative InSAR observations and tying them to the stage's vertical datum. We tested the STBAS technique with two-year long Radarsat-1 data acquired during 2006-2008 over the Water Conservation Area 1 (WCA1) in the Everglades wetlands, south Florida (USA). The InSAR-derived water level data were calibrated using 13 stage stations located in the study area to generate 28 successive high spatial resolution maps (50 m pixel resolution) of absolute water levels. We evaluate the quality of the STBAS technique using a root mean square error (RMSE) criterion of the difference between InSAR observations and stage measurements. The average RMSE is 6.6 cm, which provides an uncertainty estimation of the STBAS technique to monitor absolute water levels. About half of the uncertainties are attributed to the accuracy of the InSAR technique to detect relative water levels. The other half reflects uncertainties derived from tying the relative levels to the stage stations' datum.
KEYWORDS:
Wetlands; Everglades; Interferometric synthetic aperture radar (InSAR); Small baseline subset (SBAS); Small temporal baseline subset (STBAS); Absolute water levels differential sar interferograms; permanent scatterers; forests

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(2010) Hutchinson, J.T., Langeland, K.A., MacDonald, G.E. and Querns, R. Absorption and Translocation of Glyphosate, Metsulfuron, and Triclopyr in Old World Climbing Fern (Lygodium microphyllum). Weed Science 58(2), 118-125.

 

ABSTRACT
Old World climbing fern is one of the most invasive plants in natural areas of central and southern Florida. The fern spreads across the landscape by wind-blown spores and invades isolated and undisturbed habitats such as interior portions of the Florida Everglades. Land managers in Florida have reported that multiple herbicide treatments are required to control the fern, which could indicate that herbicides do not translocate throughout the plant in long-established populations. We conducted a greenhouse study to determine the absorption and translocation patterns in Old World climbing fern using the three herbicides most commonly used for management of this plant by land managers in Florida. Using C-14-labeled herbicides, we evaluated absorption and translocation of glyphosate (2.25 kg ai ha(-1)), metsulfuron (0.10 kg ai ha(-1)), and triclopyr (1.68 kg ai ha(-1)) in Old World climbing fern using five different application scenarios (cut-and-spray, basal spray, 25% foliar spray, 50% foliar spray, and 100% foliar spray). Triclopyr was absorbed to the greatest extent (60.3%) of applied radioactive compounds compared to glyphosate (31.2%) and metsulfuron (19.8%). The majority of radioactivity remained in treated leaves for all herbicides with only small percentages of the absorbed radioactivity being detected in other plant parts. All three herbicides translocated acropetally and basipitally to some extent. Radioactivity, for the most part, translocated evenly throughout the plants but the greatest amount of radioactivity derived from triclopyr occurred in rhizomes when the cut-and-spray and basal applications were used. The radioactivity in rhizomes derived from glyphosate was greater in those treated using cut-and-spray. Based on autoradiographs, there was limited horizontal movement of any herbicide in the rhizomes of Old World climbing fern which could explain why resprouts are observed several weeks following treatment.
KEYWORDS:
Absorption; translocation; invasive ferns; natural areas; Florida great-britain; florida; herbicide; weed; schizaeaceae; management; efficacy; invasion; methyl; plants

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(2010) Ikenaga, M., Guevara, R., Dean, A.L., Pisani, C. and Boyer, J.N. Changes in Community Structure of Sediment Bacteria Along the Florida Coastal Everglades Marsh-Mangrove-Seagrass Salinity Gradient. Microbial Ecology 59(2), 284-295.

 

ABSTRACT
Community structure of sediment bacteria in the Everglades freshwater marsh, fringing mangrove forest, and Florida Bay seagrass meadows were described based on polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) patterns of 16S rRNA gene fragments and by sequencing analysis of DGGE bands. The DGGE patterns were correlated with the environmental variables by means of canonical correspondence analysis. There was no significant trend in the Shannon-Weiner index among the sediment samples along the salinity gradient. However, cluster analysis based on DGGE patterns revealed that the bacterial community structure differed according to sites. Not only were these salinity/vegetation regions distinct but the sediment bacteria communities were consistently different along the gradient from freshwater marsh, mangrove forest, eastern-central Florida Bay, and western Florida Bay. Actinobacteria- and Bacteroidetes/Chlorobi-like DNA sequences were amplified throughout all sampling sites. More Chloroflexi and members of candidate division WS3 were found in freshwater marsh and mangrove forest sites than in seagrass sites. The appearance of candidate division OP8-like DNA sequences in mangrove sites distinguished these communities from those of freshwater marsh. The seagrass sites were characterized by reduced presence of bands belonging to Chloroflexi with increased presence of those bands related to Cyanobacteria, gamma-Proteobacteria, Spirochetes, and Planctomycetes. This included the sulfate-reducing bacteria, which are prevalent in marine environments. Clearly, bacterial communities in the sediment were different along the gradient, which can be explained mainly by the differences in salinity and total phosphorus.
KEYWORDS:
16s ribosomal-rna; sulfate-reducing bacteria; in-situ hybridization; marine-sediments; gel-electrophoresis; gene analysis; water column; diversity; river; sequence

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(2010) Iricanin, N. Rebuttal Report of Nenad Iricanin, PhD. Case No. 88-1886-Civ-Moreno. South Florida Water Management District, West Palm Beach, FL, 21.

 

ABSTRACT (none)
KEYWORDS:

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(2010) Janardhanan, L. and Daroub, S.H. Phosphorus Sorption in Organic Soils in South Florida. Soil Science Society of America Journal 74(5), 1597-1606.

 

ABSTRACT
The Everglades Agricultural Area (EAA), downstream of Lake Okeechobee in South Florida, was initially drained in the early 20th century for agriculture and flood protection. Drainage water from the EAA, enriched with P, has impacted the downstream Everglades ecosystem. The organic soils in the EAA have become shallower as a result of continuing oxidation. Mixing of the organic soils with the underlying limestone bedrock may have resulted in increased CaCO3. Our objectives were to determine the P sorption capacity of selected Histosols in the EAA with various soil depths and its relationships with selected physicochemical properties of the soils. Sorption experiments were performed on field-moist soils representing three series. These soils are taxonomically similar and differ in 0 horizon depth to bedrock. Both Langmuir and Freundlich sorption models fit the data well. Langmuir P sorption maxima (S-max) on a mass basis ranged from 733 to 6767 mg kg(-1) and are comparable to mineral soils on a volume basis. In general, P sorption variables were not different among the soils investigated except for the Freundlich sorption coefficient K-P which was lowest in the Pahokee soil, indicating lower P sorption capacity. Langmuir S-max was positively correlated with pH and oxalate-extractable Fe and Al, but not with CaCO3 content. The S-max was inversely correlated with organic matter and water-extractable P. Phosphorus sorption in these organic soils is affected by an increased mineral content, mainly poorly crystalline Fe and Al oxides, but we found no evidence that shallower soils had higher sorption capacities due to increased CaCO3 as hypothesized.
KEYWORDS:
everglades agricultural area; calcareous soils; wetland soils; sediments; water; matter; capacities; subsidence; retention; aluminum

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(2010) Jones, T.J., Luton, C.D., Santiago, L.S. and Goldstein, G. Hydraulic constraints on photosynthesis in subtropical evergreen broad leaf forest and pine woodland trees of the Florida Everglades. Trees-Structure and Function 24(3), 471-478.

 

ABSTRACT
The relationship between water transport and photosynthesis represents the trade-off between carbon gain and water loss and was used to evaluate potential differences in water resource utilization among two dominant vegetation types of south Florida: subtropical evergreen broad leaf forests (hardwood hammocks) and pine woodlands (pine rocklands). We found consistent linear positive relationships between the quantum yield of photosystem II (I center dot (PSII)), an index of photosynthetic capacity, and hydraulic conductivity per sapwood area (k (S)) and per leaf area (k (L)) across all species. The slope of the I center dot (PSII)-k (S) relationship was steeper for hardwood hammock than for pine rockland species. Mean I center dot (PSII) was greater in pine rockland species and was greater for a given k (L) than in hardwood hammock species. These results are consistent with previous observations demonstrating that pine rocklands tend to have better access to stable water sources than hardwood hammocks. We also found greater photosynthetic carbon isotope discrimination with increasing k (S) and k (L) in pine rockland species, but not in hardwood hammock species, suggesting increased stomatal conductance with increasing k (S) and k (L), consistent with greater water availability in pine rockland habitats. Our study thus utilizes relationships between water transport and photosynthesis to evaluate hydraulic constraints on physiological function between two contrasting vegetation types with contrasting stability of water sources.
KEYWORDS:
Carbon stable isotope; Chlorophyll fluorescence; South Florida; Hydraulic conductivity; Photosynthetic capacity chlorophyll fluorescence analysis; water transport-properties; stomatal conductance; trait relationships; electron-transport; functional traits; co2 assimilation; woody-plants; coordination; architecture

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(2010) Jopp, F., DeAngelis, D.L. and Trexler, J.C. Modeling seasonal dynamics of small fish cohorts in fluctuating freshwater marsh landscapes.
Landscape Ecology 25(7), 1041-1054.

 

ABSTRACT
Small-bodied fishes constitute an important assemblage in many wetlands. In wetlands that dry periodically except for small permanent waterbodies, these fishes are quick to respond to change and can undergo large fluctuations in numbers and biomasses. An important aspect of landscapes that are mixtures of marsh and permanent waterbodies is that high rates of biomass production occur in the marshes during flooding phases, while the permanent waterbodies serve as refuges for many biotic components during the dry phases. The temporal and spatial dynamics of the small fishes are ecologically important, as these fishes provide a crucial food base for higher trophic levels, such as wading birds. We develop a simple model that is analytically tractable, describing the main processes of the spatio-temporal dynamics of a population of small-bodied fish in a seasonal wetland environment, consisting of marsh and permanent waterbodies. The population expands into newly flooded areas during the wet season and contracts during declining water levels in the dry season. If the marsh dries completely during these times (a drydown), the fish need refuge in permanent waterbodies. At least three new and general conclusions arise from the model: (1) there is an optimal rate at which fish should expand into a newly flooding area to maximize population production; (2) there is also a fluctuation amplitude of water level that maximizes fish production, and (3) there is an upper limit on the number of fish that can reach a permanent waterbody during a drydown, no matter how large the marsh surface area is that drains into the waterbody. Because water levels can be manipulated in many wetlands, it is useful to have an understanding of the role of these fluctuations.
KEYWORDS:
Wetlands; Transient and permanent waterbodies; Aquatic food web; Trophic cascades; Water level fluctuations; Wetland management; Maximum biomass production; Everglades community structure; trophic interactions; everglades; disturbance; population; wetland; florida; management; predators; movement

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(2010) Ju, S. and DeAngelis, D.L. Nutrient fluxes at the landscape level and the R* rule. Ecological Modelling 221(2), 141-146.

 

ABSTRACT
Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.
KEYWORDS:
Nutrient cycling; Tree growth; Vegetation modeling; Wetlands; Tree islands everglades; enrichment

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(2010) Kaplan, D., Munoz-Carpena, R. and Ritter, A. Untangling complex shallow groundwater dynamics in the floodplain wetlands of a southeastern US coastal river. Water Resources Research 46

 

ABSTRACT
Understanding the hydrological functioning of tidally influenced floodplain forests is essential for advancing ecosystem protection and restoration goals in impacted systems. However, finding direct relationships between basic hydrological inputs and floodplain hydrology is hindered by complex interactions between surface water, groundwater, and atmospheric fluxes in a variably saturated matrix with heterogeneous soils, vegetation, and topography. Thus, an explanatory method for identifying common trends and causal factors is required. Dynamic factor analysis (DFA), a time series dimension reduction technique, models temporal variation in observed data as linear combinations of common trends, which represent unidentified common factors, and explanatory variables. In this work, DFA was applied to model water table elevation (WTE) in the floodplain of the Loxahatchee River (Florida, USA), where altered watershed hydrology has led to changing hydroperiod and salinity regimes and undesired vegetative changes in the floodplain forest. The technique proved to be a powerful tool for the study of interactions among 29 long-term, nonstationary hydrological time series (12 WTE series and 17 candidate explanatory variables). Regional groundwater circulation, surface water elevations, and spatially variable net local recharge (cumulative rainfall - cumulative evapotranspiration) were found to be the main factors explaining groundwater profiles. The relative importance of these factors was spatially related to floodplain elevation, distance from the river channel, and distance upstream from the river mouth. The resulting dynamic factor model (DFM) simulated the WTE time series well (overall coefficient of efficiency, C-eff = 0.91) and is useful for assessing management scenarios for ecosystem restoration and predicted sea level rise.
KEYWORDS:
agricultural area adjacent; everglades-national-park; common trends; time-series; saltwater intrusion; loxahatchee river; south florida; state-park; model; estuarine

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(2010) Key, P.B., Chung, K.W., Venturella, J.J., Shaddrick, B. and Fulton, M.H. Acute toxic effects of endosulfan sulfate on three life stages of grass shrimp, Palaemonetes pugio. Journal of Environmental Science and Health Part B-Pesticides Food Contaminants and Agricultural Wastes 45(1), 53-57.

 

ABSTRACT
In this study, the toxicity of endosulfan sulfate, the primary degradation product of the insecticide endosulfan, was determined in three life stages of the grass shrimp (Palaemonetes pugio). After 96 h exposure to endosulfan sulfate, the grass shrimp adult LC50 was 0.86 mu g/L (95% CI 0.56-1.31), the grass shrimp larvae LC50 was 1.64 mu g/L (95% CI 1.09-2.47) and the grass shrimp embryo LC50 was 45.85 mu g/L (95% CI 23.72-88.61 mu g/L). This was compared to the previously published grass shrimp 96-h LC50s for endosulfan. The toxicity of the two compounds was similar for the grass shrimp life stages with adults more sensitive than larvae and embryos. The presence of sediment in 24h endosulfan sulfate-exposures raised LC50s for both adult and larval grass shrimp but not significantly. The USEPA expected environmental concentrations (EEC) for total endosulfan and endosulfan sulfate and the calculations of risk quotients (RQ) based on the more sensitive adult grass shrimp 96-h LC50 clearly show that environmental concentrations equal to acute EECs would prove detrimental to grass shrimp or other similarly sensitive aquatic organisms. These results indicate that given the persistence and toxicity of endosulfan sulfate, future risk assessments should consider the toxicity potential of the parent compound as well as this degradation product.
KEYWORDS:
Endosulfan sulfate; endosulfan; Palaemonetes pugio; insecticide agricultural pesticide-residues; surface-water; bay; everglades

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(2010) Khalil, A.F., Kwon, H.H., Lall, U. and Kaheil, Y.H. Predictive downscaling based on non-homogeneous hidden Markov models.
Hydrological Sciences Journal-Journal Des Sciences Hydrologiques 55(3), 333-350.

 

ABSTRACT
Weather-state models have been shown to be effective in downscaling the synoptic atmospheric information to local daily precipitation patterns. We explore the ability of non-homogeneous hidden Markov models (NHMM) to downscale regional seasonal climate data to daily rainfall at a collection of gauging sites. The predictors used are: ensemble means of seasonal rainfall as forecast by the DEMETER and ECHAM models, and the preceding seasonal outgoing long-wave radiation (OLR). As the downscaling of seasonal GCM-based predictions lacks the ability to capture the intra-seasonal variability, we augment the seasonal GCM-driven inputs with statistically-driven predictions of the monthly rainfall amounts. The pooling effect of combining seasonal and monthly estimates of the regional rainfall enhances the capacity of the NHMM to simulate the stochastic characteristics of rainfall fields. The monthly rainfall prediction is derived from a wide range of climate precursors such as the El Nino-Southern Oscillation, local sea-level pressure, and sea-surface temperature. Application of the methodology to data from the Everglades National Park region in South Florida, USA is presented for the seasons May-July and August-September using a 22-year sequence of seasonal data from eight rainfall stations. The model skill in capturing the seasonal and intra-seasonal rainfall attributes at each station is demonstrated graphically and using simple statistical measures of efficiency. The hidden states derived from NHMM are qualitatively analysed and shown to correspond to the dominant synoptic-scale features of rainfall generating mechanisms, which reinforces the argument that physical processes are appropriately captured.
KEYWORDS:
downscaling; weather generator; precipitation; Markov models synoptic atmospheric patterns; relevance vector machine; climate-change scenarios; precipitation

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(2010) King, R.S. and Baker, M.E. Considerations for analyzing ecological community thresholds in response to anthropogenic environmental gradients. Journal of the North American Benthological Society 29(3), 998-1008.

 

ABSTRACT
The goal of this paper is to help managers better understand implications of using aggregate community metrics, such as taxon richness or Indices of Biotic Integrity (IBI), for detecting threshold responses to anthropogenic environmental gradients. To illustrate, we offer an alternative analytical approach, Threshold Indicator Taxa ANalysis (TITAN), geared toward identifying synchronous changes in the distribution of multiple taxa as evidence of an ecological community threshold. Our approach underscores the fundamental reality that which taxa are affected by stressors is important, both from a conservation standpoint and because taxon-specific life-history traits help us understand relevant mechanisms. First, we examine macroinvertebrate community response to an impervious cover gradient using a well-studied biomonitoring data set to show that representative community metrics are relatively insensitive to synchronous threshold declines of numerous individual taxa. We then reproduce these response relationships using a simulated community data set with similar properties to demonstrate that linear or wedge-shaped responses of community metrics to anthropogenic gradients can occur as an artifact of aggregating multiple taxa into a single value per sampling unit, despite strong nonlinearity in community response. Our findings do not repudiate the use of community metrics or multimetric indices, but they challenge assumptions that such metrics are capable of accurately reflecting community thresholds across a broad range of anthropogenic gradients. We recommend an alternative analysis framework that begins with characterization of the responses of individual taxa and uses aggregation only after distinguishing the magnitude, direction, and uncertainty in the responses of individual members of the community.
KEYWORDS:
bioassessment; biodiversity; biological integrity; conservation; streams; water quality water-quality criteria; coastal urbanization; urban catchments; regime shifts; management; stream; biodiversity; everglades; phosphorus; identification

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(2010) Kuo, Y.M. and Lin, H.J. Dynamic factor analysis of long-term growth trends of the intertidal seagrass Thalassia hemprichii in southern Taiwan.
Estuarine Coastal and Shelf Science 86(2), 225-236.

 

ABSTRACT
We examined environmental factors which are most responsible for the 8-year temporal dynamics of the intertidal seagrass Thalassia hemprichii in southern Taiwan. A dynamic factor analysis (DFA), a dimension-reduction technique, was applied to identify common trends in a multivariate time series and the relationships between this series and interacting environmental variables. The results of dynamic factor models (DFMs) showed that the leaf growth rate of the seagrass was mainly influenced by salinity (Sal), tidal range (TR), turbidity (K), and a common trend representing an unexplained variability in the observed time series. Sal was the primary variable that explained the temporal dynamics of the leaf growth rate compared to TR and K. K and TR had larger influences on the leaf growth rate in low- than in high-elevation beds. In addition to K, TR, and Sal, UV-B radiation (UV-B), sediment depth (SD), and a common trend accounted for long-term temporal variations of the above-ground biomass. Thus, K, TR, Sal, UV-B, and SD are the predominant environmental variables that described temporal growth variations of the intertidal seagrass T hemprichii in southern Taiwan. In addition to environmental variables, human activities may be contributing to negative impacts on the seagrass beds: this human interference may have been responsible for the unexplained common trend in the DFMs. Due to successfully applying the DFA to analyze complicated ecological and environmental data in this study, important environmental variables and impacts of human activities along the coast should be taken into account when managing a coastal environment for the conservation of intertidal seagrass beds.
KEYWORDS:
above-ground biomass; leaf growth rate; salinity; tidal range; turbidity; human activity zostera-marina l; agricultural area adjacent; everglades-national-park; uv-b radiation; climate-change; common trends; carbon budget; water-quality; time-series; coral-reefs

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(2010) Kwon, H.Y., Grunwald, S., Beck, H.W., Jung, Y.C., Daroub, S.H., Lang, T.A. and Morgan, K.T. Modeling of Phosphorus Loads in Sugarcane in a Low-Relief Landscape Using Ontology-based Simulation. Journal of Environmental Quality 39(5), 1751-1761.

 

ABSTRACT
Water flow and P dynamics in a low-relief landscape manipulated by extensive canal and ditch drainage systems were modeled utilizing an ontology-based simulation model. In the model, soil water flux and processes between three soil inorganic P pools (labile, active, and stable) and organic P are represented as database objects. And user-defined relationships among objects are used to automatically generate computer code (Java) for running the simulation of discharge and P loads. Our objectives were to develop ontology-based descriptions of soil P dynamics within sugarcane- (Saccharum officinarum L.) grown farm basins of the Everglades Agricultural Area (EAA) and to calibrate and validate such processes with water quality monitoring data collected at one farm basin (1244 ha). In the calibration phase (water year [WY] 99-00), observed discharge totaled 11,114 m(3) ha(-1) and dissolved P 0.23 kg P ha(-1); and in the validation phase (WY 02-03), discharge was 10,397 m(3) ha(-1) and dissolved P 0.11 kg P ha(-1) During WY 99-00 the root mean square error (RMSE) for monthly discharge was 188 m(3) ha(-1) and for monthly dissolved P 0.0077 kg P ha(-1); whereas during WY 02-03 the RMSE for monthly discharge was 195 m(3) ha(-1) and monthly dissolved P 0.0022 kg P ha(-1). These results were confirmed by Nash-Sutcliffe Coefficient of 0.69 (calibration) and 0.81 (validation) comparing measured and simulated P loads. The good model performance suggests that our model has promise to simulate P dynamics, which may be useful as a management tool to reduce P loads in other similar low-relief areas.
KEYWORDS:
everglades agricultural area; gulf-of-mexico; management-practices; light interception; simplified soil; drainage water; south florida; river-basin; nitrogen; systems

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(2010) Lago, M.E., Miralles-Wilhelm, F., Mahmoudi, M. and Engel, V. Numerical modeling of the effects of water flow, sediment transport and vegetation growth on the spatiotemporal patterning of the ridge and slough landscape of the Everglades wetland. Advances in Water Resources 33(10), 1268-1278.

 

ABSTRACT
A numerical model has been developed to simulate the spatiotemporal patterning of the ridge and slough landscape in wetlands, characterized by crests (ridges) and valleys (sloughs) that are elongated parallel to the direction of water flow. The model formulation consists of governing equations for integrated surface water and groundwater flow, sediment transport, and soil accretion, as well as litter production by vegetation growth. The model simulations show how the spatial pattern self-organizes over time with the generation of ridges and sloughs through sediment deposition and erosion driven by the water flow field. The spatial and temporal distributions of the water depth, flow rates and sediment transport processes are caused by differential flow due to vegetation and topography heterogeneities. The model was parameterized with values that are representative of the Everglades wetland in the southern portion of the Florida peninsula in the USA. Model simulation sensitivity was tested with respect to numerical grid size, lateral vegetation growth and the rate of litter production. The characteristic wavelengths of the pattern in the directions along and perpendicular to flow that are simulated with this model develop over time into ridge and slough shapes that resemble field observations. Also, the simulated elevation differences between the ridges and sloughs are of the same order of those typically found in the field. The width of ridges and sloughs was found to be controlled by a lateral vegetation growth distance parameter in a simplified formulation of vegetation growth, which complements earlier modeling results in which a differential peat accretion mechanism alone did not reproduce observations of ridge and slough lateral wavelengths. The results of this work suggest that ridge and slough patterning occurs as a result of vegetation's ability to grow laterally, enhancing sediment deposition in ridge areas, balanced by increased sediment erosion in slough areas to satisfy flow continuity. The interplay between sediment transport, water flow and vegetation and soil dynamic processes needs to be explored further through detailed field experiments, using a model formulation such as the one developed in this work to guide data collection and interpretation. This should be one of the focus areas of future investigations of pattern formation and stability in ridge and slough areas.
KEYWORDS:
Modeling; Ridge and slough; Patterning; Everglades national-park; florida; hydrology; dynamics; botswana; stress; origin; forest; space; trees

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(2010) Lang, T.A., Oladeji, O., Josan, M. and Daroub, S. Environmental and management factors that influence drainage water P loads from Everglades Agricultural Area farms of South Florida. Agriculture Ecosystems & Environment 138(3-4), 170-180.

 

ABSTRACT
Environmental impacts from drainage water phosphorus (P) loads from Everglades Agricultural Area (EAA) farms in South Florida led to the adoption of best management practices (BMPs). The BMPs have been very successful at reducing EAA farm drainage water P loads. However, analytical investigation into how environmental and management factors affect farm P loading may allow additional improvements in BMP performance. Sixteen variables that included cropping systems, water management, and farm specific constants were hypothesized to affect farm P loads. Data collected from ten farms between 1992 and 2002 were analyzed using Spearman correlation, Principal Component Analysis, and stepwise multivariate regression. Monthly farm P load on a unit area basis (UAL) showed stronger correlation with drainage unit area volume (UAV) than with flow weighted total P concentration (FWTP). The UAL was negatively correlated with irrigation demand and positively correlated with irrigation P concentration, rainfall, preceding month's rain, drainage pumping to rainfall ratio, and percent fallow plus flooded field acreage (PFFA). A positive correlation between soil depth and FWTP was significant Stepwise regression analysis identified canal water level management, percent sugarcane acreage, PFFA, and irrigation water P concentration as explanatory variables that impact farm P loads; PCA revealed similar results. The study suggests that lower pumping to rainfall ratio and increased sugarcane acreage lead to lower farm P loads; that irrigation water P concentration impacts farm P loads; and that shallower soils export less P than deeper soils.
KEYWORDS:
Agricultural runoff; Best management practice; Histosol; Multiple linear regression; Phosphorus load; Principal Component Analysis inorganic phosphorus; principal components; mississippi river; stopping rules; quality; table; groundwater; subsidence; landscape; number

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(2010) Lantz, S.M., Gawlik, D.E. and Cook, M.I. The Effects of Water Depth and Submerged Aquatic Vegetation on the Selection of Foraging Habitat and Foraging Success of Wading Birds. Condor 112(3), 460-469.

 

ABSTRACT
Successful foraging by avian predators is influenced largely by prey availability, which encompasses not only the density of prey but also its vulnerability to capture. For wading birds (Ciconiiformes), habitat features such as water depth and density of vegetation are thought to affect the vulnerability of their aquatic prey. In January and April 2007 we experimentally manipulated the depth of water and density of submerged aquatic vegetation (SAV) in enclosures (10 x 10 m) with equal densities of fish to determine their effects on wading birds' selection of foraging habitat and foraging success. Analysis of the results with Manly's selection index showed that wading birds preferred habitat with shallow water and SAV. The two habitat components had little effect on the birds' foraging success, however, as capture rate did not vary with water depth or SAV density. Capture efficiency did not vary by SAV density and was actually lower in shallow water, contrary to our expectations. Our results suggest that birds selected habitat on the basis of environmental cues such as water depth and SAV but that these factors did not affect foraging success strongly. We hypothesize that wading birds were selecting habitat with shallow water and SAV because of an anticipated benefit to foraging through elevated density and vulnerability of prey, but the relatively high and uniform density of prey stocked in the enclosures, as well as the scale of the enclosures, effectively equalized the vulnerability of prey across treatments.
KEYWORDS:
foraging; prey availability; Everglades; foraging-habitat selection; foraging success jersey salt-marsh; florida everglades; breeding-season; ardea-herodias; predation risk; patch use; behavior; herons; food; egrets

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(2010) Larsen, L.G., Aiken, G.R., Harvey, J.W., Noe, G.B. and Crimaldi, J.P. Using fluorescence spectroscopy to trace seasonal DOM dynamics, disturbance effects, and hydrologic transport in the Florida Everglades. Journal of Geophysical Research-Biogeosciences 115(

 

ABSTRACT
Dissolved organic matter (DOM) quality reflects numerous environmental processes, including primary production and decomposition, redox gradients, hydrologic transport, and photochemistry. Fluorescence spectroscopy can detect groups of DOM compounds sensitive to these processes. However, different environmental gradients (e. g., redox, DOM provenance) can have confounding effects on DOM fluorescence spectra. This study shows how these confounding effects can be removed through discriminant analyses on parallel factor modeling results. Using statistically distinct end-members, we resolve spatiotemporal trends in redox potential and DOM provenance within and between adjacent vegetation communities in the patterned ridge and slough landscape of the Everglades, where biogeochemical differences between vegetation communities affect net peat accretion rates and persistence of landscape structure. Source discrimination of DOM in whole-water samples and peat leachates reveals strong temporal variability associated with seasonality and passage of a hurricane and indicates that hurricane effects on marsh biogeochemistry persist for longer periods of time (>1 year) than previously recognized. Using the DOM source signal as a hydrologic tracer, we show that the system is hydrologically well mixed when surface water is present, and that limited transport of flocculent detritus occurs in surface flows. Redox potential discrimination shows that vertical redox gradients are shallower on ridges than in sloughs, creating an environment more favorable to decomposition and diagenesis. The sensitivity, high resolution, rapidity, and precision of these statistical analyses of DOM fluorescence spectra establish the technique as a promising performance measure for restoration or indicator of carbon cycle processes in the Everglades and aquatic ecosystems worldwide.
KEYWORDS:
dissolved organic-matter; humic substances; fulvic-acid; chemical characteristics; multivariate-analysis; electron-acceptors; ground-water; redox state; carbon; wetland

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(2010) Larsen, L.G. and Harvey, J.W. How Vegetation and Sediment Transport Feedbacks Drive Landscape Change in the Everglades and Wetlands Worldwide. American Naturalist 176(3), E66-E79.

 

ABSTRACT
Mechanisms reported to promote landscape self-organization cannot explain vegetation patterning oriented parallel to flow. Recent catastrophic shifts in Everglades landscape pattern and ecological function highlight the need to understand the feedbacks governing these ecosystems. We modeled feedback between vegetation, hydrology, and sediment transport on the basis of a decade of experimentation. Results from more than 100 simulations showed that flows just sufficient to redistribute sediment from sparsely vegetated sloughs to dense ridges were needed for an equilibrium patterned landscape oriented parallel to flow. Surprisingly, although vegetation heterogeneity typically conveys resilience, in wetlands governed by flow/sediment feedbacks it indicates metastability, whereby the landscape is prone to catastrophic shifts. Substantial increases or decreases in flow relative to the equilibrium condition caused an expansion of emergent vegetation and loss of open-water areas that was unlikely to revert upon restoration of the equilibrium hydrology. Understanding these feedbacks is critical in forecasting wetland responses to changing conditions and designing management strategies that optimize ecosystem services, such as carbon sequestration or habitat provision. Our model and new sensitivity analysis techniques address these issues and make it newly apparent that simply returning flow to predrainage conditions in the Everglades may not be sufficient to restore historic landscape patterns and processes.
KEYWORDS:
Everglades; wetlands; alternate stable states; modeling; patterned landscapes; sediment transport catastrophic shifts; spatial complexity; pattern-formation; slough landscape; national-park; ecosystems; models; ridge; eutrophication; restoration

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(2010) Lehman, P.W., Mayr, S., Mecum, L. and Enright, C. The freshwater tidal wetland Liberty Island, CA was both a source and sink of inorganic and organic material to the San Francisco Estuary. Aquatic Ecology 44(2), 359-372.

 

ABSTRACT
It is hypothesized that perennial freshwater tidal wetland habitat exports inorganic and organic material needed to support the estuarine food web and to create favorable habitat for aquatic organisms in San Francisco Estuary. It is also hypothesized that most of the material flux in this river-dominated region is controlled by river flow. The production and export of material by Liberty Island were measured and compared using discrete monthly and continuous (15 min) measurements of a suite of inorganic and organic materials and flow between 2004 and 2005. Seasonal material flux was estimated from monthly discrete data for inorganic nutrients, suspended solids and salts, organic carbon and nitrogen and phytoplankton and zooplankton group carbon and chlorophyll a and pheophytin pigment. Estimates of material flux from monthly values were compared with measured daily material flux values for chlorophyll a concentration, salt and suspended solids obtained from continuous measurements (15 min) using YSI water quality sondes. Phytoplankton carbon produced within the wetland was estimated by in situ primary productivity. Most inorganic and organic materials were exported from the wetland on an annual basis, but the magnitude and direction varied seasonally. Dissolved inorganic nutrients such as nitrate, soluble phosphorus, total phosphorus and silica as well as total suspended solids were exported in the summer while total and dissolved organic carbon were exported in the winter. Salts like chloride and bromide were exported in the fall. Chlorophyll a and pheophytin were exported in the fall and associated with diatom and cyanobacteria carbon. Mesozooplankton carbon was dominated by calanoid copepods and exported most of the year except summer. Continuous sampling revealed high hourly and daily variation in chlorophyll a, salt and total suspended solids flux due to high frequency changes in concentration and tidal flow. In fact, tidal flow rather than river discharge was responsible for 90% or more of the material flux of the wetland. These studies indicate that freshwater tidal wetlands can be a source of inorganic and organic material but the export of material is highly variable spatially and temporally, varies most closely with tidal flow and requires high frequency measurements of both tidal flow and material concentration for accurate estimates.
KEYWORDS:
Freshwater tidal wetland; Material flux; Phytoplankton; Zooplankton; Tide; Estuary floodplain system; bay estuary; river; nutrient; phytoplankton; everglades; nitrogen; usa; retention; biomass

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(2010) Lewis, D.E., White, J.R., Wafula, D., Athar, R., Dickerson, T., Williams, H.N. and Chauhan, A. Soil Functional Diversity Analysis of a Bauxite-Mined Restoration hronosequence. Microbial Ecology 59(4), 710-723.

 

ABSTRACT
Soil microorganisms are sensitive to environmental perturbations such that changes in microbial community structure and function can provide early signs of anthropogenic disturbances and even predict restoration success. We evaluated the bacterial functional diversity of un-mined and three chronosequence sites at various stages of rehabilitation (0, 10, and 20 years old) located in the Mocho Mountains of Jamaica. Samples were collected during the dry and wet seasons and analyzed for metal concentrations, microbial biomass carbon, bacterial numbers, and functional responses of soil microbiota using community-level physiological profile (CLPP) assays. Regardless of the season, un-mined soils consisted of higher microbial biomass and numbers than any of the rehabilitated sites. Additionally, the number and rate of substrates utilized and substrate evenness (the distribution of color development between the substrates) were significantly greater in the un-mined soils with carbohydrates being preferentially utilized than amino acids, polymers, carboxylic acids, and esters. To some extent, functional responses varied with the seasons but the least physiological activity was shown by the site rehabilitated in 1987 indicating long-term perturbation to this ecosystem. Small subunit ribosomal DNA (SSUrDNA)-denaturing gradient-gel electrophoresis analyses on the microbiota collected from the most preferred CLPP substrates followed by taxonomic analyses showed Proteobacteria, specifically the gamma-proteobacteria, as the most functionally active phyla, indicating a propensity of this phyla to out-compete other groups under the prevailing conditions. Additionally, multivariate statistical analyses, Shannon's diversity, and evenness indices, principal component analysis, biplot and un-weighted-pair-group method with arithmetic averages dendrograms further confirmed that un-mined sites were distinctly different from the rehabilitated soils.
KEYWORDS:
level physiological profiles; microbial communities; management-practices; florida everglades; reclamation; classification; associations; ecosystem; patterns; gradient

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(2010) Li, S.W., Lissner, J., Mendelssohn, I.A., Brix, H., Lorenzen, B., McKee, K.L. and Miao, S.L. Nutrient and growth responses of cattail (Typha domingensis) to redox intensity and phosphate availability. Annals of Botany 105(1), 175-184.

 

ABSTRACT
In the Florida Everglades, the expansion of cattail (Typha domingensis) into areas once dominated by sawgrass (Cladium jamaicense) has been attributed to altered hydrology and phosphorus (P) enrichment. The objective of this study was to quantify the interactive effects of P availability and soil redox potential (Eh) on the growth and nutrient responses of Typha, which may help to explain its expansion. The study examined the growth and nutrient responses of Typha to the interactive effects of P availability (10, 80 and 500 mu g P L-1) and Eh level (-150, +150 and +600 mV). Plants were grown hydroponically in a factorial experiment using titanium (Ti3+) citrate as a redox buffer. Relative growth rate, elongation, root-supported tissue/root ratio, leaf length, lateral root length and biomass, as well as tissue nutrient concentrations, were all adversely affected by low Eh conditions. P availability compensated for the negative effect of low Eh for all these variables except that low P stimulated root length and nutrient use efficiency. The most growth-promoting treatment combination was 500 mu g P L-1/ + 600 mV. These results, plus previous data on Cladium responses to P/Eh combinations, document that high P availability and low Eh should benefit Typha more than Cladium as the growth and tissue nutrients of the former species responded more to excess P, even under highly reduced conditions. Therefore, the interactive effects of P enrichment and Eh appear to be linked to the expansion of Typha in the Everglades Water Conservation Area 2A, where both low Eh and enhanced phosphate availability have co-occurred during recent decades.
KEYWORDS:
Everglades; growth; nutrient; phosphorus; redox potential; Typha domingensis cladium-jamaicense cyperaceae; everglades plant-communities; root oxygen stress; florida everglades; northern everglades; eutrophication gradient; phosphorus deficiency; rhynchospora-tracyi; soil; sawgrass

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(2010) Li, X., Nour, M.H., Smith, D.W. and Prepas, E.E. Neural networks modelling of nitrogen export: model development and application to unmonitored boreal forest watersheds. Environmental Technology 31(5), 495-510.

 

ABSTRACT
In remotely located boreal forest watersheds, monitoring nitrogen (N) export in stream discharge often is not feasible because of high costs and site inaccessibility. Therefore, modelling tools that can predict N export in unmonitored watersheds are urgently needed to support management decisions for these watersheds. The hydrological and biogeochemical processes that regulate N export in streams draining watersheds are complex and not fully understood, which makes artificial neural network (ANN) modelling suitable for such an application. This study developed ANN models to predict N export from watersheds relying only on easily accessible climate data and remote sensing (RS) data from the public domain. The models were able to predict the daily N export (g/km(2)/d) in five watersheds ranging in size from 5-130 km(2) with reasonable accuracy. Similarity indices were developed between any two studied watersheds to quantify watershed similarity and guide the transferability of models from monitored watersheds to unmonitored ones. To demonstrate the applicability of the ANN models to unmonitored watersheds, the calibrated ANN models were used to predict N export in different watersheds (unmonitored watersheds in this perspective) without further calibration. The similarity index based upon a rainfall index, a peatland index and a RS normalized difference water index showed the best correlation with the transferability of the models. This study represents an important first step towards transferring ANN models developed for one watershed to unmonitored watersheds using similarity indices that rely on freely available climate and RS data.
KEYWORDS:

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(2010) Li, Y.B., Mao, Y.X., Liu, G.L., Tachiev, G., Roelant, D., Feng, X.B. and Cai, Y. Degradation of Methylmercury and Its Effects on Mercury Distribution and Cycling in the Florida Everglades. Environmental Science & Technology 44(17), 6661-6666.

 

ABSTRACT
Methylmercury (MeHg) is recognized as one of the major water quality concerns in the Florida Everglades. Degradation of MeHg in the water is thought to be one of the most important processes to the cycling of MeHg, but there is a lack of quantitative estimations of its effect on the distribution and cycling of MeHg in this ecosystem. Stable isotope (MealFlg) addition method was implemented to investigate the degradation of MeHg in the Everglades. By combining these results with the field monitoring data, effects of photodegradation on MeHg distribution and its contribution to MeHg cycling were estimated. The results indicate that degradation of MeHg in Everglades water is mediated by sunlight and that UV-A and UV-B radiations are the principal driver. The spatial pattern of MeHg photodegradation potential (Pm) generally illustrated an increasing trend from north to south in the Everglades, which was opposite to the distribution of MeHg in water column. Correlation analysis shows that MeHg concentration in the water had a significant negative relation to PpD, suggesting that photodegradation could play an important role in controlling the distribution of MeHg in Everglades water. Furthermore, about 31.4% of MeHg input into the water body was removed by photodegradation, indicating its importance in the biogeochemical cycling of MeHg in the Everglades. This percent reduction is much lower than that reported for other ecosystems, which could be caused by the higher concentration of DOG in the Everglades. The relatively slower degradation of MeHg could be one of the main reasons for the high ratio of MeHg to total mercury (THg) in this ecosystem.
KEYWORDS:
natural-waters; ultraviolet-radiation; lakes; monomethylmercury; methylation; chloride; demethylation; rates; sea

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(2010) Liu, D.Y. and Song, C.C. Effects of inorganic nitrogen and phosphorus enrichment on the emission of N2O from a freshwater marsh soil in Northeast China. Environmental Earth Sciences 60(4), 799-807.

 

ABSTRACT
The freshwater marshes in northern China are heavily impacted by anthropogenic disturbances such as cultivation and fertilization and increased levels of nutrients (especially N and P) through atmospheric deposition and agricultural surface runoff. These disturbances have affected the emission of N2O from these systems. This laboratory study was conducted to determine the effects of increased inputs of inorganic N and P on N2O emission from marsh soil in response to different soil moisture conditions. The results showed that the emission of N2O increased with the enhancement of N inputs when the soil was submerged, but that the highest N treatment suppressed the emission of N2O when the soil was at 60% water holding capacity (WHC), which may have occurred due to an inadequate amount of available C. Furthermore, the results of this study indicated that a small amount of N fertilizer induced much more N2O evolution from freshwater wetland soil, while P fertilizer inputs appeared to stimulate the emission of N2O only during the first few days of the experiment. Additionally, soil that was treated with P appeared to absorb N2O when it was at 60% WHC after around 6 weeks of the incubation, which indicates that the input of P fertilizer might serve as a shift of source or N2O sink in wetland soils under non-flooded conditions. When compared to soil at 60% WHC, submerged soil had significantly higher N2O emissions, except when subjected to the medial N treatment. These findings indicate that the soil moisture condition had a significant effect on N2O emissions when the same amount of N or P was applied. Therefore, the effects of N and P fertilization in the northern temperate wetlands cannot be neglected from regional or national emissions of N2O.
KEYWORDS:
N fertilizer; P fertilizer; N2O emission; Soil moisture condition; Wetland everglades wetland soils; sanjiang plain; forest soils; florida everglades; methane emission; enzyme-activity; oxide emission; carbon-dioxide; denitrification; fertilizer

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(2010) Liu, G.D., Gu, B., Miao, S.L., Li, Y.C., Migliaccio, K.W. and Qian, Y. Phosphorus Release from Ash and Remaining Tissues of Two Wetland Species after a Prescribed Fire. Journal of Environmental Quality 39(5), 1585-1593.

 

ABSTRACT
Dead plant tissues and ash from a prescribed fire play an important role in nutrient balance and cycling in the Florida Everglades ecosystem. The objective of this study was to assess the dynamic changes in total phosphorus release (TPr) from ash or tissues of either cattail (Typha domingensis Pers.) or sawgrass (Canon jamaicense Crantz) to water. Natural-dead (senesced-dead) and burning-dead (standing-dead due to a prescribed fire) cattail and sawgrass were collected from highly (H) and moderately (M) impacted zones in the Florida Everglades. This experiment was conducted by incubation and water-extraction of the materials in plastic bottles for 65 d at room temperature (24 +/- 1 degrees C). Results showed that 63 to 88%, 17 to 48%, 9 to 20%, and 13 to 28% of total P (TPp) were released as TPr from cattail and sawgrass ash, cattail tissues from the H zone, cattail tissues, and sawgrass tissues from the M zone, respectively. TPp means total P of plant tissues, whereas TPr is total P release from the tissues or ash. Most of the TPr was released within 24 h after burning. The quick release of TPr observed in this experiment may help explain the P surge in the surface water immediately following a fire in the marsh. These findings suggest that prescribed burning accelerates P release from cattail and sawgrass. They also imply that it is very important to keep the water stagnant in the first 24 h to maximize the benefits of a prescribed fire in the Everglades.
KEYWORDS:
cattail typha-domingensis; florida everglades; cladium-jamaicense; soil

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"Everglades" literature for year 2010 CONTINUED on a separate page

   

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