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(2010) Mao, Y.X., Yin, Y.G., Li, Y.B., Liu, G.L., Feng, X.B., Jiang, G.B. and Cai, Y. Occurrence of monoethylmercury in the Florida Everglades: Identification and verification. Environmental Pollution 158(11), 3378-3384.

 

ABSTRACT
A few studies have reported the occurrence of monoethylmercury (CH3CH2Hg+) in the natural environment. but further verification is needed due to the lack of direct evidence and/or uncertainty in analytical procedures. Various analytical techniques were employed to verify the occurrence of CH3CH2Hg+ in soil of the Florida Everglades The identity of CH3CH2Hg+ in Everglades soil was clarified, for the first time, by GC/MS. The employment of the recently developed aqueous phenylanon-purge-and-trap-GC coupled with ICPMS confirmed that the detected CH3CH2Hg+ was not a misidentification of CH3SHg+. Stable Isotope-tracer experiments further indicated that the detected CH3CH2Hg+ indeed originated from Everglades soil and was not an analytical artifact All these evidence clearly confirmed the occurrence of CH3CH2Hg+ in Everglades soil, presumably as a consequence of ethylation occurring in this wetland The prevalence of CH3CH2Hg+ in Everglades soil suggests that ethylation could play an important role in the biogeochemical cycling of Hg
KEYWORDS:
Monoethylmercury; Occurrence; Soil; Everglades; Isotope tracer atomic fluorescence spectrometry; unintentional abiotic methylation; capillary gas-chromatography; solid-phase extraction; organomercury compounds; liquid-chromatography; inorganic mercury; isotope addition; icp-ms; methylmercury

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(2010) Mares, J. Anabaena fuscovaginata (Nostocales), a new cyanobacterial species from periphyton of the freshwater alkaline marsh of Everglades, South Florida, USA. Fottea 10(2), 235-243.

 

ABSTRACT
A new species of the nostocalean genus Anabaena was discovered in periphytic cyanobacterial mats of the Everglades marsh, South Florida, USA. In some of the 10 samples where it occurred, the species dominated the cyanobacterial community, however, it was always part of a rich assemblage of microbiota, including many types characteristic for alkaline herbaceous wetlands of Caribbean America or freshwater tropical marshes. On the basis of typical morphological traits and occurrence in a periphytic habitat, I suggest that the species is a member of the genus Anabaena in its original sense, valid after recent separation of planktic taxa. As the most distinctive morphological feature, it has firm, coloured sheaths that have never been reported for this genus before.
KEYWORDS:
alkaline marshes; Anabaena; cyanobacteria; Everglades; morphology; periphyton; taxonomy cyanophytes cyanobacteria; subg. dolichospermum; taxonomic evaluation; genera anabaena; genus anabaena; cuba; aphanizomenon; phosphorus; microflora; diversity

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(2010) Martin, M.R., Tipping, P.W., Reddy, K.R., Daroub, S.H. and Roberts, K.M. Interactions of biological and herbicidal management of Melaleuca quinquenervia with fire: Consequences for ecosystem services. Biological Control 54(3), 307-315.

 

ABSTRACT
Exotic plant species invasion can alter ecosystem nutrient dynamics and natural disturbance patterns. The Australian tree Melaleuca quinquenervia has extensively invaded the Florida Everglades and is currently being suppressed using mechanical, herbicidal, and biological control management strategies. While these methods have been evaluated based on reductions in density and abundance of the target weed, other factors should be considered including consequences for ecosystem nutrient storages and interactions with natural disturbances such as fire. We hypothesized that the choice of management tactics, namely herbicidal or biological control, would differentially influence the quantity and availability of soil nutrients before and after a seasonal fire. The management of M. quinquenervia with a herbicide reduced the above-and belowground storage of nutrients both before and after a fire compared to a non-invaded area, while biological control increased storage. There were no differences in nitrogen availability between sites (non-invaded, herbicide, biological control) in the 0-5 cm or 5-15 cm soil depths before or after the fire. Pre-fire phosphorus availability was highest in the non-invaded site in the 05 cm soil depth and in the biological control site in the 5-15 cm soil depth. However, phosphorus availability was highest at both depths in the herbicide site post-fire. Biological control of M. quinquenervia using insect herbivores has proven to be effective at controlling plant growth and reproduction. The results of this study suggest that this method may have less of an impact on nutrient storage and cycling than herbicides.
KEYWORDS:
Fire; Invasion; Exotic; Nutrient; Melaleuca quinquenervia oxyops-vitiosa coleoptera; control agent; plant invasion; introduced insects; microbial biomass; australian weevil; cav. blake,s.t.; host-range; nitrogen; dynamics

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(2010a) McCray, J.M., Ji, S., Powell, G., Montes, G. and Perdomo, R. Sugarcane Response to DRIS-Based Fertilizer Supplements in Florida.
Journal of Agronomy and Crop Science 196(1), 66-75.

  ABSTRACT
Soil testing is the primary basis for fertilizer recommendations in Florida sugarcane (Saccharum spp.), but it has the limitations of generally being performed only before the plant cane crop and not providing information for nitrogen or micronutrient availability. Leaf analysis is a useful diagnostic tool that can complement soil testing and may allow more cost-effective fertilizer applications for each crop. The Diagnosis and Recommendation Integrated System (DRIS) was used to determine leaf nutrient status in a study evaluating the effectiveness of a summer fertilizer supplement. There were 19, 24 and 26 paired commercial field comparisons in 2004/05, 2005/06 and 2006/07 respectively. Each field of each test pair received normally recommended fertilizer applications based on pre-plant soil tests, with one field of each pair receiving a June/July fertilizer supplement based on DRIS indices of leaf samples collected in April/May. There was no response in tonnes of sugarcane ha) 1 or sugar tonne cane) 1 to the fertilizer supplements for organic or mineral soils or for plant or first ratoon crops. A more cost-effective use of leaf analysis appears to be with the adjustment of the next amendment or fertilizer application, generally for next year's crop or at the next sugarcane planting, rather than adding an additional fertilizer supplement to the current crop.
KEYWORDS:
DRIS; fertilizer; leaf analysis; nutrient management; Saccharum spp.; tissue analysis; nutritional equilibrium integrated-system dris; nutritional diagnosis; grassland swards; nutrient status; norms; establishment; calibration; everglades; validation; histosols

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(2010b) McCray, J.M., Rice, R.W., Luo, Y.G. and Ji, S.N. Sugarcane Response to Phosphorus Fertilizer on Everglades Histosols.
Agronomy Journal 102(5), 1468-1477.

 

ABSTRACT
Determining sugarcane (Saccharum spp.) yield response to P fertilizer supports the development of agricultural best management practices consistent with Everglades restoration efforts. Field studies were conducted on organic soils to determine sugarcane yield responses to P fertilizer. Four test sites were established on Florida Histosols (water-extractable P = 1.3, 1.7, 2.1, and 9.0 g P m(-3)) with annual banded rates of 0, 9, 18, 36, 72, and 144 kg P ha(-1). There were a total of 13 crop years with duration of each test ranging from 2 to 4 yr. Linear and quadratic regression and single degree of freedom contrasts were used to determine P fertilizer requirements. There were responses in t cane ha(-1) (TCH) and t sucrose ha(-1) (TSH) to P fertilizer application at four and three sites, respectively. Annual fertilizer P requirement at the four sites ranged from 18 to 33 kg P ha(-1), with no consistent change in P requirement across crop years. Based on measured response (95% of maximum yield) in TCH and TSH up to 33 kg P ha(-1), the maximum P recommendation for sugarcane grown on Florida Histosols should be maintained at 36 kg P ha(-1). Minimal reductions in sucrose concentration (kg sucrose t(-1) cane) were measured at P rates <= 36 kg P ha(-1). Water-extractable P did not predict the measured yield response at all sites, demonstrating the need for an updated soil test calibration that should be applicable over a wide pH range and include both quickly available and reserve soil P.
KEYWORDS:
management-practices; florida everglades; agricultural area; soil; enrichment

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(2010) McIvor, C.C. and Silverman, N.L. Modifications to the bottomless lift net for sampling nekton in tidal mangrove forests.
Wetlands Ecology and Management 18(6), 627-635.

 

ABSTRACT
Sampling fishes in vegetated intertidal wetlands is logistically challenging. We modified the 2 x 3-m(2) bottomless lift net developed for sampling nekton (fish and decapod crustaceans) on the surface of salt marshes for use in tidal mangrove forests with a woody (as opposed to herbaceous) underground root system. As originally designed (Rozas, Mar Ecol Prog Ser 89:287-292, 1992), the lift net was buried directly in the marsh substrate. The net was raised at slack high tide thereby encircling nekton within the enclosed area. A chain-line on the net bottom prevented escape under the net once deployed. However, when we used this same design in tidal mangrove forests, the extensive woody roots and occasional slumping sediments resulted in uneven trenches that could not be cleared effectively during sample recovery. We made 3 modifications to the original net design: (i) lined the peat trenches with aluminum channels of uniform width and depth; (ii) replaced the previous chain-line with Velcro closures that directly attached the net to the inner face of the outer wall of the aluminum channel; and (iii) removed the subtidal pan previously used for concentrating the enclosed nekton at low tide, and filled in those depressions with on-site peat. In the modified version, the aluminum trench became the only subtidal refuge available to nekton, and it was from here that we collected the sample after the forest drained. These modifications permitted high clearing efficiency (93-100%) of fin-clipped individuals of two common species of estuarine resident fishes, Kryptolebias marmoratus (mangrove rivulus) and Bathygobius soporator (frillfin goby). Additionally, the density estimates of grass shrimp (Palaemonetes spp.) increased 10-fold post-modification.
KEYWORDS:
Clearing efficiency; Everglades National Park; Modified lift net; Nekton; Riverine mangroves; Vegetated intertidal zone community structure; fishes; bay; crustaceans; densities; australia; habitats; marshes

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(2010) Meselhe, E.A., Arceneaux, J.C. and Waldon, M.G. Water budget model for a remnant northern Everglades wetland.
Journal of Hydraulic Research 48(1), 100-105.

 

ABSTRACT
The Arthur R. Marshall Loxahatchee National Wildlife Refuge overlays Water Conservation Area 1, a 580 km(2) freshwater wetland remnant of the northern Everglades in Palm Beach County, Florida, USA. Changes in water quantity and quality have impacted the Refuge ecosystem. Ensuring appropriate management to maximize benefits for wildlife while meeting flood control and water supply needs is a refuge priority. The Simple Refuge Stage Model described herein supports these management decisions. The two-compartment model with a daily time step predicts temporal variations of water level in the refuge rim canal and interior marsh, based on observed inflows, outflows, precipitation and evapotranspiration. The model was used to evaluate various water management scenarios. The modelling approach applied herein may have utility in managing other wetland systems where over-bank flooding is a dominant mechanism, affecting hydrology and water quality.
KEYWORDS:
Everglades; mass balance; seepage; stage; water budget; wetlands

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(2010) Miao, S.L., Edelstein, C., Carstenn, S. and Gu, B.H. Immediate ecological impacts of a prescribed fire on a cattail-dominated wetland in Florida Everglades. Fundamental and Applied Limnology 176(1), 29-41.

 

ABSTRACT
The effects of fire on nutrient release in wetlands prior to, during and afterwards are notably rare. We initiated a long-term and large-scale ecosystem study, driven by a large restoration program, to assess ecological effects of repeated fires on a nutrient-enriched, cattail-dominated wetland in the Florida Everglades. Here, we report the immediate and short-term (30 days) impacts of the first prescribed fire focusing on a central question of whether the fire affected surface-and pore-water nutrient concentrations and forms. Specifically, we addressed several questions: 1) how fast could the impacts be detected, 2) what were the magnitude and duration of the impacts, and 3) were there any downstream effects detected and if so, how far downstream was the impact observed? The results showed that post-fire increases of average surface water total phosphorus (TP) concentrations over 10 days were 128 %, 119 %, and 135 % for within burned plot, 25 m downstream, and 100 m downstream, respectively, relative to the upstream control (82 +/- 11 mu g L-1). A post-fire surface water pH peak (8.4) was observed as soon as 15 minutes after the fire reached within burned plot, and the increase in pH lasted at least three weeks. A significant increase (400 %) in the daily peak dissolved oxygen was detected by the third week post-fire. Daily maximum water temperature increased 2-4 degrees C post-fire and this increase lasted the duration of the 30-day sampling period. Average periphyton TP concentrations from samples collected within burned plot were 3495 +/- 320 mg kg(-1) one month post-fire, but decreased to 1730 +/- 219 mg kg(-1) three months post-fire. Cattail seed germination decreased (41 %) from pre- to post-fire, while seed germination of sawgrass and other species increased (97 % and 12 %, respectively). Overall, whether these short-term responses have sustained effects and how they will shape other entities of the ecosystem in the long-term are currently being investigated and will be assessed in the near future.
KEYWORDS:
Surface water; pore water; total phosphorus; TDP; TDKN; DIC; periphyton; seed germination seed-germination; inorganic carbon; water chemistry; ecosystems; dynamics; usa; vegetation; smoke

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(2010) Min, J.H., Paudel, R. and Jawitz, J.W. Spatially distributed modeling of surface water flow dynamics in the Everglades ridge and slough landscape.
Journal of Hydrology 390(1-2), 1-12.

 

ABSTRACT
A two-dimensional, spatially distributed flow dynamics model was developed and tested for a 1.5 by 4 km area of the patterned ridge and slough landscape of the Florida Everglades. This model is intended to support a deepened understanding of the system ecohydrological dynamics, and provide a useful tool for management decision support. The model was constructed with a fine enough mesh structure to ensure proper representation of ridge and slough topographic detail as well as capture local hydrologic influences. Upstream and downstream stage data collected near the study area in central Water Conservation Area 3A were used to establish the initial and boundary conditions. Water velocities measured in the ridges and sloughs over a 3-year period were used to calibrate and verify the model. Hydraulic resistance was computed using a power-law relationship with water depth. The simulated water levels, water depths, and flow velocities showed good agreement with the 3-year field-monitored data with percent model errors of approximately 4%, 12%, and 10%, respectively. Computed differences in hydraulic resistance between ridge and slough were reduced significantly during the storm season compared to the dry season. This suggests that more solute and suspended solid mass can be redistributed from the sloughs to the ridges in particular during wet seasons, due to the weakened heterogeneity of hydraulic resistance during high flows.
KEYWORDS:
Everglades; Ridge and slough; Distributed model; Hydraulic resistance; Flow velocity; Hydroperiod south florida; overland-flow; hydraulic efficiency; constructed wetlands; national-park; vegetation; hydrology; ecosystem; resuspension; floodplain

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(2010) Min, J.H. and Wise, W.R. Depth-averaged, spatially distributed flow dynamic and solute transport modelling of a large-scaled, subtropical constructed wetland. Hydrological Processes 24(19), 2724-2737.

 

ABSTRACT
Constructed wetlands are being utilized worldwide to effectively reduce excess nutrients in agricultural runoff and wastewater. Despite their frequency, a multi-dimensional, physically based, spatially distributed modelling approach has rarely been applied for flow and solute transport in treatment wetlands. This article presents a two-dimensional hydrodynamic and solute transport modelling of a large-scaled, subtropical, free water surface constructed wetland of about 8 km(2) in the Everglades of Florida, USA. In this study, MIKE 21 was adopted as the basic model framework. Field monitoring of the time series hydrological and chloride data, as well as spatially distributed data such as bathymetry and vegetation distribution, provided the necessary model input and testing data. Simulated water level profiles were in good agreement with the spatio-temporal variations of measured ones. On average, the root-mean-square error of model calibration on annual water level fluctuations was 0.09 m. Manning's roughness coefficients for the dense emergent and submerged aquatic vegetation areas, which were estimated as a function of vegetation type, ranged from 0.67 to 1.0 and 0.12 to 0.15 s/m(1/3), respectively. The solute transport model calibration for four monitoring sites agreed well with the measured annual variations in chloride concentration with an average percent model error of about 15%. The longitudinal dispersivity was estimated to be about 2 m and was more than an order of magnitude higher than the transverse one. This study is expected to play the role of a stepping stone for future modelling efforts on the development and application of more advanced flow and transport models applicable to a variety of constructed wetland systems, as well as to the Everglades stormwater treatment areas in operation or in preparation.
KEYWORDS:
free water surface constructed wetland; hydrodynamics; solute transport; distributed modelling; hydraulic resistance; dispersivity 3-dimensional hydrodynamic model; through emergent vegetation; everglades restoration; south florida; nutrient removal; lake okeechobee; water-quality; mike she; phosphorus;

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(2010) Moravec, F. and Bakenhaster, M. Philometrid nematodes infecting fishes from the Everglades National Park, Florida, USA, with description of two new species. Folia Parasitologica 57(3), 213-222.

 

ABSTRACT
The following three species of the Philometridae (Nematoda: Dracunculoidea) are described from marine perciform fishes of the Everglades National Park (northern Gulf of Mexico), Florida, USA: Philometra brevispicula sp. n. (male and females) from the subcutaneous tissue of mouth of the gray snapper Lutjanus griseus (Linnaeus) (Lutjanidae), Philometroides grandipapillotus sp. n. (only females) from pectoral fin muscle of the crevalle jack Caranx hippos (Linnaeus) (Carangidae), and Caranginema americanum Moravec, Montoya-Mendoza et Salgado-Maldonado, 2008 (females) from the subcutaneous fascia of trunk muscle in crevalle jack C. hippos. Philometra brevispicula is mainly characterized by small cephalic papillae of the external circle, the absence of oesophageal teeth and the presence of small caudal projections in gravid female, markedly short spicules (45 mu m) in male, and by its location in the host. Philometroides grandipapillatus differs from congeners mainly in the shape of the cephalic region (narrow, conspicuously protruding), large cephalic papillae of the external circle and the absence of caudal projections in female, and by the site of infection in the host. Caranginema americanum is for the first time recorded from the northern Gulf of Mexico.
KEYWORDS:
parasitic nematode; Philometra; Philometroides; Caranginema; marine fish; Lutjanus; Caranx; Florida; Gulf of Mexico gulf-of-mexico; south-carolina; paralichthys-lethostigma; dracunculoid nematodes; lateolabracis yamaguti; subcutaneous tissue; sp n.; osteichthyes; musculature; sciaenidae

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(2010) Naja, G.M., Rivero, R., Davis, S.E. and Van Lent, T. Hydrochemical impacts of limestone mining. Water Air and Soil Pollution217(1-4), 95-104.

 

ABSTRACT
Hydrochemical impacts of shallow rock industrial-scale mining activities close to sensitive constructed and natural wetlands were investigated. The shallow surficial groundwater and surface water in the Everglades Agricultural Area (EAA) were characterized. The chemical composition of sulfate and chloride in groundwater increased with depth. The average concentration of chloride averaged 182 mg/L at 6 m deep and increased gradually to 1,010 mg/L at 15 m deep, 1,550 mg/L at 30 m deep to reach 7,800 mg/L at 60 m deep. Comparatively, the surface water chemical composition in the surrounding areas showed much lower cationic and anionic charge. The specific conductivity and total dissolved solids of surface water in canals (close to the mining operations) are <900 µS/cm and <600 mg/L, respectively, which should be compared to groundwater quality in wells from the EAA area (>2,000 µS/cm and >1,000 mg/L, respectively). A steady-state groundwater fluid flow and transient solute transport modeling exercise was conducted to estimate surface/groundwater interactions. The modeled solute in surface water was transported downgradient through groundwaters, migrated approximately 30 m from the source area (after 5 years of operation), and needed more than 116 years to dissipate. An upward transport was also identified whereby chloride and sulfate, naturally present in deeper groundwaters, migrated approximately 200 m (after 1 year of mining) into the pristine shallower aquifer and reached the surface water with a concentration equaling 80% of that in the rock mining pit.
KEYWORDS:
Groundwater/surface water interactions . Everglades Agricultural Area . Chloride . Sulfate

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(2010) Nas, B., Ekercin, S., Karabork, H., Berktay, A. and Mulla, D.J. An Application of Landsat-5TM Image Data for Water Quality Mapping in Lake Beysehir, Turkey. Water Air and Soil Pollution 212(1-4), 183-197.

 

ABSTRACT
The main goal of this study was to investigate spatial patterns in water quality in Lake Beysehir, which is the largest freshwater reservoir in Turkey, by using Landsat-5TM (Thematic Mapper) data and ground surveys. Suspended sediment (SS), turbidity, Secchi disk depth (SDD), and chlorophyll-a (chl-a) data were collected from 40 sampling stations in August, 2006. Spatial patterns in these parameters were estimated using bivariate and multiple regression (MR) techniques based on Landsat-5TM multispectral data and water quality sampling data. Single TM bands, band ratios, and combinations of TM bands were estimated and correlated with the measured water quality parameters. The best regression models showed that the measured and estimated values of water quality parameters were in good agreement (0.60 < R (2) < 0.71). TM3 provided a significant relationship (R (2) = 0.67, p < 0.0001) with SS concentration. MR between chl-a and various combinations of TM bands showed that TM1, TM2, and TM4 are strongly correlated with measured chl-a concentrations (R (2) = 0.60, p < 0.0001). MR of turbidity showed that TM1, TM2, and TM3 explain 60% (p < 0.0001) of the variance in turbidity. MR of SDD showed a strong relationship with measured SDD, with R (2) = 0.71 (p < 0.0001) for the ratio TM1/TM3 and TM1 band combinations. The spatial distribution maps present apparent spatial variations of selected parameters for the study area covering the largest freshwater lake and drinking water reservoir in Turkey. Interpretation of thematic water quality maps indicated similar spatial distributions for SS, turbidity, and SDD. A large area in the middle portion of the lake showed very low chl-a concentrations as it is far from point and nonpoint sources of incoming nutrients. The trophic state index values were calculated from chl-a and SDD measurements. Lake Beysehir was classified as a mesotrophic or eutrophic lake according to chl-a or SDD parameters, respectively.
KEYWORDS:

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(2010) Noe, G.B., Harvey, J.W., Schaffranek, R.W. and Larsen, L.G. Controls of Suspended Sediment Concentration, Nutrient Content, and Transport in a Subtropical Wetland. Wetlands 30(1), 39-54.

 

ABSTRACT
Redistribution of largely organic sediment from low elevation sloughs to higher elevation ridges is a leading hypothesis for the formation and maintenance of the native ridge and slough landscape pattern found in peat wetlands of the Florida Everglades. We tested this redistribution hypothesis by measuring the concentration and characteristics of suspended sediment and its associated nutrients in the flowpaths of adjacent ridge and slough plant communities. Over two wet seasons we found no sustained differences in suspended sediment mass concentrations, particle-associated P and N concentrations, or sizes of suspended particles between ridge and slough sites. Discharge of suspended sediment, particulate nutrients, and solutes were nearly double in the slough flowpath compared to the ridge flowpath due solely to deeper and faster water flow in sloughs. Spatial and temporal variations in suspended sediment were not related to water velocity, consistent with a hypothesis that the critical sheer stress causing entrainment is not commonly exceeded in the present-day managed Everglades. The uniformity in the concentrations and characteristics of suspended sediment at our research site suggests that sediment and particulate nutrient redistribution between ridges and sloughs does not occur, or rarely occurs, in the modern Everglades.
KEYWORDS:
Entrainment; Everglades; Nitrogen; Particle; Phosphorus everglades national-park; coastal wetland; slough landscape; soil-phosphorus; water; vegetation; particles; removal; impact; ridge

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(2010) Orem, W., Gilmour, C., Axelrad, D., Krabbenhoft, D., Scheidt, D., Kalla, P., McCormick, P., Gabriel, M. and Aiken, G. Sulfur in the South Florida Ecosystem: Distribution, sources, biogeochemistry, impacts, & management for restoration. Environmental Science & Technology Critical Reviews (TBD)

 

ABSTRACT
Sulfur is broadly recognized as a water quality issue of significance for the freshwater Florida Everglades. Roughly 60% of the remnant Everglades has surface water sulfate concentrations above 1 mg l-1, a restoration performance measure based on current sulfate levels in unenriched areas. Highly enriched marshes in the northern Everglades have average sulfate levels of 60 mg l-1. Sulfate loading to the Everglades is principally a result of land and water management in South Florida. The highest concentrations of sulfate (average 60-70 mg l-1) in the ecosystem are in canal water in the Everglades Agricultural Area (EAA). Potential sulfur sources in the watershed are many, but geochemical data and a preliminary sulfur mass balance for the EAA are consistent with sulfur currently used in agricultural, and sulfur released by oxidation of organic EAA soils (including legacy agricultural applications, and natural sulfur) as the primary sources of sulfate enrichment in the EAA canals.
Sulfate loading to the Everglades increases microbial sulfate reduction in soils, leading to more reducing conditions, greater cycling of nutrients in soils, production of toxic sulfide, and enhanced methylmercury (MeHg) production and bioaccumulation. Wetlands are zones of naturally high MeHg production, but the combination of high atmospheric mercury deposition rates in South Florida and elevated sulfate loading, leads to increased MeHg production and MeHg risk to Everglades wildlife and human consumers.
Sulfate from the EAA drainage canals penetrates deep into the Everglades Water Conservation Areas, and may extend into Everglades National Park. Current plans to restore sheet flow and to deliver more water to the Everglades may increase overall sulfur loads to the ecosystem, and move sulfate-enriched water further south. However, water management practices that minimize soil drying and rewetting cycles can mitigate sulfate release during soil oxidation.
A comprehensive Everglades restoration strategy should include reduction of sulfur loads as a goal because of the many detrimental impacts of sulfate on the ecosystem. Monitoring data show that the ecosystem response to changes in sulfate levels is rapid, and strategies for reducing sulfate loading may be effective in the near-term. A multifaceted approach employing best management practices for sulfur in agriculture, agricultural practices that minimize soil oxidation, and changes to stormwater treatment areas that increase sulfate retention could help achieve reduced sulfate loads to the Everglades, with resulting benefits.
KEYWORDS:

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(2010) Paudel, R., Min, J.H. and Jawitz, J.W. Management scenario evaluation for a large treatment wetland using a spatio-temporal phosphorus transport and cycling model. Ecological Engineering 36(12), 1627-1900.

 

ABSTRACT
This paper describes the development of a two-dimensional, spatially distributed model to simulate coupled hydrologic and phosphorus (P) biogeochemical processes in a 147-ha cell of a 1544-ha stormwater treatment wetland designed to help protect the greater Everglades, FL USA. The model was used to assess the effects of a suite of feasible management alternatives on the long-term ability of the wetland to sustain total P (TP) removal. The spatial and temporal dynamics of TP retention were simulated under historical (1995-2000) conditions, and under assumptions of removal of short-circuiting channels and ditches, changes in external hydraulic and TP loading, and long-term (>20 years) impacts on soil and water column TP dynamics under current and reduced load conditions. Internal hydrology and transport processes were calibrated against measured tracer concentrations, and subsequently validated against outflow discharge and spatial chloride concentration data. Cycling of P was simulated as first-order uptake and release, with different uptake coefficients for open water/sparse submerged aquatic vegetation (SAV) areas (0.2 day(-1)) and dense SAV areas (0.4 day(-1)), and a much lower, uniform release coefficient (1.97 x 10(-4) day(-1)). The calibration and validation of the P model showed good agreement with field measurements of water column TP concentrations measured at the wetland outlet (calibration RMSE = 10.5 mu g L-1; validation RMSE = 15.6 mu g L-1). Under simulated conditions of preferential channels eliminated, average annual TP treatment effectiveness increased by 25%. When inflow TP loads were assumed to be eliminated after 6 years of loading, the release of accumulated soil P sustained predicted annual average outlet concentrations above 6.7 mu g L-1 for 18 years, decreasing at a rate of 0.16 mu g L-1 yr(-1). Sensitivity analyses indicate that the most critical model input factors include flow resistance parameters, initial soil TP content, and P cycling parameters compared to initial water level. initial TP concentration in water column, ET and transport parameters.
KEYWORDS:
Spatially distributed; Model; Everglades; Stormwater; Phosphorus; Management nutrient-removal-project; subtropical constructed wetland; south florida usa; ecosystem model; overland-flow; everglades; vegetation; dynamics

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(2010) Payne, G., Xue, S.K., Hallas, K. and Weaver, K. Appendix 3A-6: Annual Total Phosphorus Criteria Compliance Assessment for Water Year 2005 through Water Year 2009. Florida Department of Environmental Protection and South Florida Water Management District, Tallahassee and West Palm Beach, FL, 12.

 

ABSTRACT
The Florida Everglades is extremely oligotrophic and sensitive to small increases in phosphorus (P) concentrations. P enrichment is one of the dominant anthropogenic impacts on the ecosystem and is therefore a main focus of restoration efforts. In this review, we synthesize research on P biogeochemistry and the impact of P enrichment on ecosystem structure and function in the Florida Everglades. There are clear patterns of increased P concentrations and altered structure and processes along nutrient-enrichment gradients in the water, periphyton, soils, macrophytes, and consumers. Periphyton, an assemblage of algae, bacteria, and associated microfauna, is abundant and has a large influence on phosphorus cycling in the Everglades. The oligotrophic Everglades is P-starved, has lower P concentrations and higher nitrogen-phosphorus (N:P) ratios, and has oxidized to only slightly reduced soil profiles compared to other freshwater wetland ecosystems. Possible general causes and indications of P limitation in the Everglades and other wetlands include geology, hydrology, and dominance of oxidative microbial nutrient cycling. The Everglades may be unique with respect to P biogeochemistry because of the multiple causes of P limitation and the resulting high degree of limitation.
KEYWORDS:

top     full text (2010) Payne, G.G., Xue, S.K., Hallas, K. and C. Weaver, K.C. Chapter 3A: Status of Water Quality in the Everglades Protection Area. 75.
 

ABSTRACT (none)
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KEYWORDS:

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(2010) Pearlstine, L.G., Pearlstine, E.V. and Aumen, N.G. A review of the ecological consequences and management implications of climate change for the Everglades. Journal of the North American Benthological Society 29(4), 1510-1526.

 

ABSTRACT
Southern Florida's Everglades are at the front line of potential negative effects on aquatic ecosystems from climate change and associated sea-level rise. A diversity of aquatic habitats supports a rich assemblage of aquatic and terrestrial wildlife, including 36 vertebrates and 26 plant species federally listed as endangered, threatened, or candidate species. Anticipated climate-change trends for southern Florida include increased weather uncertainty with more droughts, higher temperatures, and an increased number of more intense storms. Hydrologic regimes, temperature, and CO2 have been strongly correlated with plant community structure, coral and fish abundance and diversity, and higher trophic-level responses. Higher levels of variability in extreme climatic events, such as droughts, have the potential to destabilize aquatic communities. Sea-level rise is expected to be 0.8 to 2 m over the next century, a serious problem in a landscape that rises only 5 cm/km from Florida Bay inland. Wading birds and other wildlife species dependent on fresh water are likely to decline because of salt-water overwash and inundation. In addition to causing habitat loss, saltwater inundation of the peat substrate of Everglades freshwater wetlands may increase C emissions from sequestered C released as peat is destroyed and freshwater plant communities die. Identification of those species and habitats most at risk and ways to increase habitat and landscape resilience to large-scale environmental change will be critical for maintaining a diverse and productive Everglades.
KEYWORDS:
Climate change; sea level rise; Everglades; ecology; management elevated atmospheric co2; sea-level rise; antarctic ice-sheet; carbon-dioxide; evolutionary responses; ocean acidification; florida everglades; soil respiration; private land; coral-reefs

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(2010) Pivnickova, B., Rejmankova, E., Snyder, J.M. and Santruckova, H. Heterotrophic microbial activities and nutritional status of microbial communities in tropical marsh sediments of different salinities: the effects of phosphorus addition and plant species. Plant and Soil 336(1-2), 49-63.

 

ABSTRACT
Oligotrophic, phosphorus (P) limited herbaceous wetlands of northern Belize are being impacted by P loading from fertilizer runoff. P enrichment causes a shift in autotroph communities from a microphyte (cyanobacterial mats, CBM) to macrophyte (Eleocharis spp., Typha domingensis) dominated system. To document potential effects of P, salinity, and macrophyte species on the heterotrophic microbial community nutritional status (represented especially by specific phospholipids fatty acids and specific respiration rate), biomass and activities, we took soil samples from established P enrichment plots in replicated marshes of two salinity levels. P addition increased microbial biomass carbon (C), nitrogen (N) and P, as well as soil nutrient transformation rates (nitrogenase activity, N mineralization and immobilization, methanogenesis). The effect of plant species (Eleocharis vs Typha sites) was generally lower than the effect of P addition (CBM vs Eleocharis sites) and was most evident at the low salinity sites, where Eleocharis dominated plots had enhanced nitrogenase activity and P microbial immobilization. Salinity reduced the overall rates of microbial processes; it also weakened the positive effect of both P addition and plant species on microbial activities. Lastly, the amount of N stored in microbial cells, likely in form of osmoprotective compounds, was enhanced by salinity.
KEYWORDS:
Phosphorus loading; Eleocharis; Typha; Salinity; Microbial biomass; Nitrogen total organic-carbon; fatty-acids; bacterial communities; cladium-jamaicense; typha-domingensis; wetland sediments; everglades marsh; northern belize; central-america; soil

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(2010) Price, R.M., Savabi, M.R., Jolicoeur, J.L. and Roy, S. Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion. Applied Geochemistry 25(7), 1085-1091.

 

ABSTRACT
This study investigates the potential release of PO43- from carbonate aquifers exposed to seawater intrusion. Adsorption and desorption of PO43- in the presence of deionized water (DIW) and seawater were conducted on a large block of Pleistocene age limestone to simulate the effects of seawater intrusion into a coastal carbonate aquifer at the laboratory scale. The limestone showed strong adsorption of PO43- in DIW, while adsorption was significantly less in the presence of seawater. Dissolution of CaCO3 was found to prevent PO43- adsorption at salinities less than 30 psu. Adsorption of PO43- was limited at higher salinities (30-33 psu), due to competition with HCO3- ions for adsorption sites. At a salinity <33, some PO43- absorption occurred as CaCO3 precipitated. Concentrations of PO43- between 2 and 5 mu mol/L were released by desorption when the limestone was exposed to seawater. The results of this study suggest that as seawater intrudes into an originally freshwater coastal aquifer, adsorbed PO43- may be released into the groundwater. Consequently, adsorbed PO43- is expected to be released from coastal carbonate aquifers world-wide as sea level continues to rise exposing more of the freshwater aquifer to seawater.
KEYWORDS:
south florida; groundwater discharge; biscayne aquifer; phosphorus; everglades; usa; dissolution; reduction; wetlands; yucatan

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(2010) Pumo, D., Tamea, S., Noto, L.V., Miralles-Wilhem, F. and Rodriguez-Iturbe, I. Modeling belowground water table fluctuations in the Everglades. Water Resources Research 46(

 

ABSTRACT
Humid lands, such as riparian zones, peatlands, and unsubmerged wetlands, are considered among the most biologically diverse of all ecosystems, providing a bountiful habitat for a large number of plant and animal species. In such ecosystems, the water table dynamics play a key role in major ecohydrological processes. The aim of the present study is to test with field data a recent analytical model for the estimation of the long-term probability distribution of the belowground water table position in groundwater-dependent environments. This model accounts for stochastic rainfall and processes such as infiltration, root water uptake, water flow from/to an external water body, and capillary fluxes. The water table model is tested using field data of groundwater levels recorded in three different sites within the Everglades (Florida, USA). A sensitivity analysis of the model to the soil and vegetation parameters is also carried out. After performing a procedure to determinate appropriate model parameters for the three sites, the steady state probability distribution functions of water table levels predicted by the model are compared to the empirical ones at both the annual and the seasonal time scale. The model is shown capable to reproduce many features of the observed distributions although there exist model predictions which still show some discrepancies with respect to the empirical observations. The potential causes for these discrepancies are also investigated and discussed.
KEYWORDS:
soil-moisture; hydraulic conductivity; controlled ecosystems; hydrologic processes; forested wetlands; active-role; peat; vegetation; dynamics; stress

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(2010) Raja, H.A., Violi, H.A. and Shearer, C.A. Freshwater ascomycetes: Alascospora evergladensis, a new genus and species from the Florida Everglades. Mycologia 102(1), 33-38.

 

ABSTRACT
Alascospora evergladensis, a freshwater ascomycete collected from submerged dead petioles of Nymphaea odorata during a survey of aquatic fungi along a phosphorus gradient in the Florida Ever glades, is described and illustrated as a new genus and species in the Pleosporales (Pleosporomycetidae, Dothideomycetes). The new fungus is unique among genera in the Pleosporales based oil a combination of morphological characters that include light brown, translucent, membranous, ostiolate ascomata with dark, amorphous material irregularly deposited oil the peridium, especially around the ostiole; globose, fissitunicate, thick-walled asci; septate pseudoparaphyses; and 1-septate ascospores that are hyaline when young, and surrounded by a hyaline gelatinous sheath that is wing-shaped in outline oil each side of the ascospore. The sheath is distinctive in that it first expands in water and is translucent, then condenses and darkens around older ascospores, giving them a dark brown, verruculose appearance.
KEYWORDS:
aquatic fungi; herbaceous; Nymphaea odorata; saprophyte; systematics decomposition

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(2010) Rand, G.M., Carriger, J.F., Gardinali, P.R. and Castro, J. Endosulfan and its metabolite, endosulfan sulfate, in freshwater ecosystems of South Florida: a probabilistic aquatic ecological risk assessment. Ecotoxicology 19(5), 879-900.

 

ABSTRACT
Endosulfan is an insecticide-acaricide used in South Florida and is one of the remaining organochlorine insecticides registered under the Federal Insecticide Fungicide and Rodenticide Act by the U.S.EPA. The technical grade material consists of two isomers (alpha-, beta-) and the main environmental metabolite in water, sediment and tissue is endosulfan sulfate through oxidation. A comprehensive probabilistic aquatic ecological risk assessment was conducted to determine the potential risks of existing exposures to endosulfan and endosulfan sulfate in freshwaters of South Florida based on historical data (1992-2007). The assessment included hazard assessment (Tier 1) followed by probabilistic risk assessment (Tier 2). Tier 1 compared actual measured concentrations in surface freshwaters of 47 sites in South Florida from historical data to U.S.EPA numerical water quality criteria. Based on results of Tier 1, Tier 2 focused on the acute and chronic risks of endosulfan at nine sites by comparing distributions of surface water exposure concentrations of endosulfan [i.e., for total endosulfan (summation of concentrations of alpha- and beta-isomers plus the sulfate), alpha- plus beta-endosulfan, and endosulfan sulfate (alone)] with distributions of species effects from laboratory toxicity data. In Tier 2 the distribution of total endosulfan in fish tissue (whole body) from South Florida freshwaters was also used to determine the probability of exceeding a distribution of whole body residues of endosulfan producing mortality (critical lethal residues). Tier 1 showed the majority of endosulfan water quality violations in South Florida were at locations S-178 followed by S-177 in the C-111 system (southeastern boundary of Everglades National Park (ENP)). Nine surface water sampling sites were chosen for Tier 2. Tier 2 showed the highest potentially affected fraction of toxicity values (> 10%) by the estimated 90th centile exposure concentration (total endosulfan) was at S-178. At all other freshwater sites there were < 5% of the toxicity values exceeded. Potential chronic risk (9.2% for total endosulfan) was only found at S-178 and all other sites were < 5%. Joint probability curves showed the higher probability of risk at S-178 than at S-177. The freshwater fish species which contain tissue concentrations of endosulfan (total) with the highest potential risk for lethal whole body tissue residues were marsh killifish, flagfish and mosquitofish. Based on existing surface water exposures and available aquatic toxicity data, there are potential risks of total endosulfan to freshwater organisms in South Florida. Although there are uncertainties, the presence of tissue concentrations of endosulfan in small demersal fish, is of ecological significance since these fish support higher trophic level species, such as wading birds.
KEYWORDS:
Comprehensive Everglades Restoration Plan (CERP); Endosulfan; alpha-endosulfan; beta-endosulfan; Endosulfan sulfate; Everglades National Park; Organochlorines; Probabilistic aquatic ecological risk assessment; South Florida; Internal effect concentration; Criticial body residue; Lethal body burden; Species sensitivity distribution biscayne national-parks; surface waters; species-sensitivity; aqueous endosulfan; alpha-endosulfan; toxicity; pesticides; degradation; bay; everglades

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(2010) Rayamajhi, M.B., Pratt, P.D., Center, T.D. and Van, T.K. Exotic tree leaf litter accumulation and mass loss dynamics compared with two sympatric native species in south Florida, USA. European Journal of Forest Research 129(6), 1155-1168.

 

ABSTRACT
The exotic tree Melaleuca quinquenervia (melaleuca) forms dense forests usually characterized by low plant diversities and dense litter biomass accumulations on forest floors of ecologically sensitive ecosystems, including portions of the Florida Everglades. We quantified litter accumulation in mature melaleuca stands and compared decomposition rates of melaleuca leaves with a sympatric native plant, either Cladium jamaicense (sawgrass) in sawgrass marshes or Pinus elliottii (slash pine) in pine flatwoods habitats that varied in soil types. Total litter accumulation in mature melaleuca forests prior to June 1997 ranged from 12.27 to 25.63 Mg ha(-1). Overall, melaleuca leaves decomposed faster in organically rich versus arenaceous soils. Decomposition rates were lower for melaleuca leaves than for sawgrass in both melaleuca-invaded and uninvaded sawgrass marshes. In arenaceous soils of pine flatwoods, melaleuca leaf and pine needle decomposition rates were similar. Complete mineralization of sawgrass leaves occurred after 258 weeks, whereas melaleuca leaves had up to 14% and pine foliage had up to 19% of the original biomass remaining after 322 weeks. Total carbon (C) in intact decomposing leaves varied slightly, but total nitrogen (N) steadily increased for all three species; the greatest being a fourfold in sawgrass. Increases in N concentrations caused decreases in the C/N ratios of all species but remained within an optimal range (20-30) in sawgrass resulting in higher decomposition rates compared to melaleuca leaves and pine needles (C/N ratio > 30). Slower decomposition of melaleuca leaves results in denser litter layers that may negatively affect recruitment of other plant species and impede their establishment in invaded communities.
KEYWORDS:
C/N ratio; Exotic plants; Invasive trees; Melaleuca quinquenervia; Pine needles; Sawgrass leaves long-term decomposition; scots pine forest; melaleuca-quinquenervia; organic-matter; nutrient release; needle litter; plant litter; soil; turnover; quality

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(2010) Richards, J.H., Dow, M. and Troxler, T. Modeling Nymphoides Architecture: A Morphological Analysis of Nymphoides Aquatica (Menyanthaceae). American Journal of Botany 97(11), 1761-1771.

 

ABSTRACT
Premise of the study : Species in the aquatic genus Nymphoides have inflorescences that appear to arise from the petioles of floating leaves. The inflorescence-floating leaf complex can produce vegetative propagules and/or additional inflorescences and leaves. We analyzed the morphology of N. aquatica to determine how this complex relates to whole plant architecture and whether whole plant growth is sympodial or monopodial. Methods : We used dissections, measurements, and microscopic observations of field-collected plants and plants cultivated for 2 years in outdoor tanks in south Florida, USA. Key results : Nymphoides aquatica had a submerged plagiotropic rhizome that produced floating leaves in an alternate/spiral phyllotaxy. Rhizomes were composed of successive sympodial units that varied in the number of leaves produced before the apex terminated. The basic sympodial unit had a prophyll that subtended a renewal-shoot bud, a short-petioledleaf (SPL) with floating lamina, and an inflorescence; the SPL axillary bud expanded as a vegetative propagule. Plants produced either successive basic sympodial units or expanded sympodia that intercalated long-petioled leaves between the prophyll and the SPL. Conclusions : Nymphoides aquatica grows sympodially, forming a rhizome composed of successive basic sympodia and expanded sympodial units. Variations on these types of sympodial growth help explain the branching patterns and leaf morphologies described for other Nymphoides species. Monitoring how these two sympodial phases are affected by water depth provides an ecologically meaningful way to assess N. aquatica's responses to altered hydrology.
KEYWORDS:
aquatic plant; clonal propagation; Everglades; heterophylly; leaf dimorphism; prophyll; slough; sympodial; vegetative reproduction o kuntze menyanthaceae; water-depth; biomass allocation; pressurized ventilation; growth; peltata; eleocharis; cyperaceae; responses; araceae

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(2010) Richardson, C.J. The Everglades: North America's subtropical wetland. Wetlands Ecology and Management 18(5), 517-542.

 

ABSTRACT
The Everglades is the largest subtropical wetland in the United States. Because of its size, floral and faunal diversity, geological history and hydrological functions on the Florida landscape, the remaining Everglades are considered to be the crown jewel of U.S. wetlands. It is also called a "sentinel wetland" to test our society's resolve for ecosystem restoration. Originally called Pa-hay-okee ("grassy lake") by the American Indians, it was later popularized as the "river of grass" by Marjory Stoneman Douglas. This metaphor unfortunately has led to a simplistic view of the complexities of the Everglades ecosystem and how it functions on the landscape. Often incorrectly referred to as the "marsh" or "swamp," the Everglades is a fen peatland or alkaline mire. These are important distinctions when one considers how different marshes and swamps are from peatlands in terms of their hydrologic controls, biogeochemistry, rate of peat development, plant and animal communities and-importantly-succession patterns. This paper provides a brief review of the geological processes that led to the development of the Everglades, compares historic and current hydrologic flow patterns, assesses nutrient conditions, presents information on vegetation communities and succession patterns, and provides a new peatland classification of the Everglades system, which may help in the development of a more appropriate restoration management framework.
KEYWORDS:
Peatland; Wetland; Classification; Hydrology; Phosphorus; Biogeochemistry; Fire; Plant communities; Ecosystem management florida everglades; eutrophication gradient; nutrient enrichment; species composition; water chemistry; peat accretion; organic soil; landscape; vegetation; usa

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(2010) Saha, A.K., Sternberg, L.D.O., Ross, M.S. and Miralles-Wilhelm, F. Water source utilization and foliar nutrient status differs between upland and flooded plant communities in wetland tree islands. Wetlands Ecology and Management 18(3), 343-355.

 

ABSTRACT
Tree islands in the Everglades wetlands are centers of biodiversity and targets of restoration, yet little is known about the pattern of water source utilization by the constituent woody plant communities: upland hammocks and flooded swamp forests. Two potential water sources exist: (1) entrapped rainwater in the vadose zone of the organic soil (referred to as upland soil water), that becomes enriched in phosphorus, and (2) phosphorus-poor groundwater/surface water (referred to as regional water). Using natural stable isotope abundance as a tracer, we observed that hammock plants used upland soil water in the wet season and shifted to regional water uptake in the dry season, while swamp forest plants used regional water throughout the year. Consistent with the previously observed phosphorus concentrations of the two water sources, hammock plants had a greater annual mean foliar phosphorus concentration over swamp forest plants, thereby supporting the idea that tree island hammocks are islands of high phosphorus concentrations in the oligotrophic Everglades. Foliar nitrogen levels in swamp forest plants were higher than those of hammock plants. Linking water sources with foliar nutrient concentrations can indicate nutrient sources and periods of nutrient uptake, thereby linking hydrology with the nutrient regimes of different plant communities in wetland ecosystems. Our results are consistent with the hypotheses that (1) over long periods, upland tree island communities incrementally increase their nutrient concentration by incorporating marsh nutrients through transpiration seasonally, and (2) small differences in micro-topography in a wetland ecosystem can lead to large differences in water and nutrient cycles.
KEYWORDS:
Tree islands; Ecohydrology; Everglades; Stable isotopes; Foliar nutrients florida everglades; phosphorus enrichment; mineral-nutrition; soil nutrient; fresh-water; wild plants; responses; patterns; linking; terrestrial

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(2010a) Salvato, M.H. and Salvato, H.L. Notes on the Status and Ecology of Anaea Troglodyta Floridalis (Nymphalidae) in Everglades National Park. Journal of the Lepidopterists Society 64(2), 91-97.

 

ABSTRACT

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(2010b) Salvato, M.H. and Salvato, H.L. Notes on the Status and Ecology of Strymon Acis Bartrami (Lycaenidae) in Everglades National Park. Journal of the Lepidopterists Society 64(3), 154-160.

 

ABSTRACT
A 10-year survey was conducted within the pine rocklands of Everglades National Park to study the status, phenology and natural history of Strymon acts bartrami (W. Huntington and Comstock). The response of populations of this species to prescribed fires and hurricane activity within the Everglades was also noted. Strymon a. bartrami (n = 77 adults) was encountered throughout the survey, most often in the spring, but was generally uncommon. The species was slow to re-colonize recently burned pine rocklands. However, prescribed fires conducted in a cyclic pattern as well as near appropriate hostplant-bearing refugia may have aided S. a. bartrami in post-burn re-establishment. In addition, the species appeared to recover quickly after hurricane events in the Everglades.
KEYWORDS:
prescribed fire; phenology; conservation; hurricanes anaea-troglodyta-floridalis; fire; lepidoptera; habitat; prairie; conservation; management; keys

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(2010) Sanchez, D.G.R., Cruz, S.C., Gil, A.P., Corona, J.S.S. and Wong, J.A.C. Kenaf (Hibiscus cannabinus L.) forage yield and quality at three ages compared to corn and brown midrib sorghum x Sudangrass. Revista Mexicana De Ciencias Pecuarias 1(1), 13-23.

 

ABSTRACT
Kenaf (Hibiscus cannabinus L.) shows forage potential as an alternative crop in farm production systems. In the present study, yield potential and forage quality in kenal varieties 'Tainting 2' and 'Everglades 41' at three different ages were evaluated, and compared to corn and brown midrib sorghum x sudangrass. The present study was conducted in Matamoros, Coahuila, Mexico in the summers of 2003 and 2004, using a randomized complete block design with four replications. Dry matter (DM) yield, forage quality and dry matter distribution among aerial plant organs were determined. Kenaf showed DM yields between 1,320 and 10,869 kg ha(-1) depending on age. significantly (P < 0.05) lower than those found in corn (13,179 to 16,380 kg ha(-1)) and sorghum (14.811 kg ha(-1)). Crude protein concentration (CP) in kenaf (9.8 to 18.6 %) was greater (P<0.05) than in corn and sorghum (7.0 to 7.9 %), whereas acid detergent fiber (ADE) and neutral detergent fiber (NDF) concentrations were similar or higher than in corn and sorghum at 66 d after sowing (this). Forage quality decreased (P<0.05) with age when DM partitioning into leaves dropped, maintaining an acceptable forage quality forage at beginning of flowering (66 to 74 das), presenting 13.5 to 15.8 % CP, 35.0 to 47.5 % ADE and 42.1 to 59.5 % NDF.
KEYWORDS:
Hibiscus cannabinus; Alternative crops; Dry matter partitioning; Chemical composition digestibility; fiber

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(2010) Sargeant, B.L., Gaiser, E.E. and Trexler, J.C. Biotic and abiotic determinants of intermediate-consumer trophic diversity in the Florida everglades. Marine and Freshwater Research 61(1), 11-22.

 

ABSTRACT
Food-web structure can shape population dynamics and ecosystem functioning and stability. We investigated the structure of a food-web fragment consisting of dominant intermediate consumers (fishes and crayfishes) in the Florida Everglades, using stable isotope analysis to quantify trophic diversity along gradients of primary production (periphyton), disturbance (marsh drying) and intermediate-consumer density (a possible indicator of competition). We predicted that trophic diversity would increase with resource availability and decrease after disturbance, and that competition could result in greater trophic diversity by favouring resource partitioning. Total trophic diversity, measured by niche area, decreased with periphyton biomass and an ordination axis representing several bluegreen algae species. Consumers' basal resource diversity, estimated by delta C-13 values, was similarly related to algal community structure. The range of trophic levels (delta N-15 range) increased with time since the most recent drying and reflooding event, but decreased with intermediate-consumer density, and was positively related to the ordination axis reflecting increases in green algae and decreases in filamentous bluegreen algae. Our findings suggest that algal quality, independent of quantity, influences food-web structure and demonstrate an indirect role of nutrient enrichment mediated by its effects on periphyton palatability and biomass. These results reveal potential mechanisms for anthropogenic effects on Everglades communities.
KEYWORDS:
competition; disturbance; food web; nutrients community-wide measures; isotope ratios provide; food-web structure; stable-isotopes; chain length; phosphorus enrichment; oligotrophic wetland; ecosystem; disturbance; competition

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(2010) Schedlbauer, J.L., Oberbauer, S.F., Starr, G. and Jimenez, K.L. Seasonal differences in the CO2 exchange of a short-hydroperiod Florida Everglades marsh. Agricultural and Forest Meteorology 150(7-8), 994-1006.

 

ABSTRACT
Although wetlands are among the world's most productive ecosystems, little is known of long-term CO2 exchange in tropical and subtropical wetlands. The Everglades is a highly managed wetlands complex occupying >6000 km(2) in south Florida. This ecosystem is oligotrophic, but extremely high rates of productivity have been previously reported. To evaluate CO2 exchange and its response to seasonality (dry vs. wet season) in the Everglades, an eddy covariance tower was established in a short-hydroperiod marl marsh. Rates of net ecosystem exchange and ecosystem respiration were small year-round and declined in the wet season relative to the dry season. Inundation reduced macrophyte CO2 uptake, substantially limiting gross ecosystem production. While light and air temperature exerted the primary controls on net ecosystem exchange and ecosystem respiration in the dry season, inundation weakened these relationships. The ecosystem shifted from a CO2 sink in the dry season to a CO2 source in the wet season; however, the marsh was a small carbon sink on an annual basis. Net ecosystem production, ecosystem respiration, and gross ecosystem production were -49.9, 446.1 and 496.0 g C m(-2) year(-1), respectively. Unexpectedly low CO2 flux rates and annual production distinguish the Everglades from many other wetlands. Nonetheless, impending changes in water management are likely to alter the CO2 balance of this wetland and may increase the source strength of these extensive short-hydroperiod wetlands.
KEYWORDS:
Ecosystem respiration; Eddy covariance; Gross ecosystem production; Net ecosystem production; Short-hydroperiod marsh; Wetland southern everglades; flux measurements; carbon-dioxide; vegetation; wetland; periphyton; responses; productivity; atmosphere; drivers

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(2010) Schofield, P.J., Loftus, W.F., Kobza, R.M., Cook, M.I. and Slone, D.H. Tolerance of nonindigenous cichlid fishes (Cichlasoma urophthalmus, Hemichromis letourneuxi) to low temperature: laboratory and field experiments in south Florida. Biological Invasions 12(8), 2441-2457.

 

ABSTRACT
The cold tolerance of two non-native cichlids (Hemichromis letourneuxi and Cichlasoma urophthalmus) that are established in south Florida was tested in the field and laboratory. In the laboratory, fishes were acclimated to two temperatures (24 and 28A degrees C), and three salinities (0, 10, and 35 ppt). Two endpoints were identified: loss of equilibrium (11.5-13.7A degrees C for C. urophthalmus; 10.8-12.5A degrees C for H. letourneuxi), and death (9.5-11.1A degrees C for C. urophthalmus; 9.1-13.3A degrees C for H. letourneuxi). In the field, fishes were caged in several aquatic habitats during two winter cold snaps. Temperatures were lowest (4.0A degrees C) in the shallow marsh, where no fish survived, and warmest in canals and solution-holes. Canals and ditches as shallow as 50 cm provided thermal refuges for these tropical fishes. Because of the effect on survival of different habitat types, simple predictions of ultimate geographic expansion by non-native fishes using latitude and thermal isoclines are insufficient for freshwater fishes.
KEYWORDS:
Cichlidae; Ecophysiology; Everglades; Low-temperature tolerance; Non-native species; Salinity fresh-water fishes; cold tolerance; lethal temperatures; oreochromis-mossambicus; everglades wetlands; blackchin tilapia; thermal tolerance; united-states; nile tilapia; salinity

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(2010) Scholz, M. and Hedmark, A. Constructed wetlands treating Runoff Contaminated with Nutrients. Water Air and Soil Pollution 205(1-4), 323-332.

 

ABSTRACT
The aim was to assess the role of Phragmites australis (Cav.) Trin. ex Steud. in experimental, mature, and temporarily flooded vertical flow wetland filters treating urban runoff rich in organic matter. During the experiment, ammonium chloride was added to sieved concentrated road runoff to simulate primary treated urban runoff contaminated with nitrogen. Five days at 20A degrees C N-allylthiourea biochemical oxygen demand (BOD) and chemical oxygen demand removal efficiencies were relatively lower for planted than unplanted filters. Moreover, there was no significant difference for BOD removal for all filters under fluctuating inflow concentrations of sulfate. The nitrogen removal performances of planted filters were more efficient and stable throughout the seasons compared to those of unplanted filters. A substantial load of nitrogen (approximately 500 mg per filter) was removed by harvesting P. australis. Plant uptake was the main removal mechanism for nitrogen during high concentrations (10 mg/L) of ammonia-nitrogen in the urban runoff.
KEYWORDS:

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(2010) Seale, D. An Everglades Providence: Marjory Stoneman Douglas and the American Environmental Century. Journal of Agricultural & Environmental Ethics 23(6), 601-609.

 

ABSTRACT (none - book review)
KEYWORDS:

top     full text (2010) Serrano, X., Grosell, M. and Serafy, J.E. Salinity selection and preference of the grey snapper Lutjanus griseus: field and laboratory observations. Journal of Fish Biology 76(7), 1592-1608.
 

ABSTRACT
Field observations were supplemented with laboratory experiments to reveal patterns of salinity selection and preference for grey snapper Lutjanus griseus (c. 21 cm total length, L-T), an ecologically and economically important species in the south-eastern U. S. A. Fish abundance data were examined from a long-term field survey conducted in the mangrove habitats of Biscayne Bay, Florida, where salinities ranged from <1 to 40. First, regression analyses indicated significant, positive linear relationships with salinity for both L. griseus frequency of occurrence and concentration (density when present). These patterns are inconsistent with physiological expectations of minimizing energetic osmoregulatory costs. Next, the salinity preference and swimming activity of 11 L. griseus (ranging from 18 to 23 cm L-T) were investigated using a newly developed electronic shuttlebox system. In the laboratory, fish preferred intermediate salinities in the range of 9-23. Swimming activity (measured in terms of spontaneous swimming speed) followed a parabolic relationship with salinity, with reduced activity at salinity extremes perhaps reflecting compensation for higher osmoregulatory costs. It is suspected that the basis of the discrepancy between laboratory and field observations for size classes at or near maturity ultimately relates to the reproductive imperative to move towards offshore (high-salinity) coral-reef habitats, a necessity that probably overrides the strategy of minimizing osmoregulatory energetic costs.
KEYWORDS:
Biscayne Bay; electronic shuttlebox; Everglades restoration; gray snapper; osmoregulation; salinity choice gray snapper; florida bay; behavioral thermoregulation; mangrove shoreline; habitat selection; temperature; growth; fish; survival; water

top     full text (2010) SFWM, 2010 South Florida Environmental Report. South Florida Water Management District, West Palm Beach, FL,
 

ABSTRACT (none - a comprehensive Report)
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(2010) Shafland, P.L., Gestring, K.B. and Stanford, M.S. An Assessment of the Asian Swamp Eel (Monopterus albus) in Florida. Reviews in Fisheries Science 18(1), 25-39.

 

ABSTRACT
The Asian swamp eel (Monopterus albus) is an air-breathing, sex-reversing, eel-like exotic fish that was first reported from Florida waters in 1997. This illegally introduced fish is now abundant in four major southeastern Florida canal systems, and it continues to slowly spread into nearby areas, including the Everglades. Swamp eel feed on a wide variety of organisms, the most common of which are small fishes, crustaceans (mostly crayfish), and insects. In a laboratory study, swamp eel died at temperatures 8 degrees C. No deleterious ecological effects associated with the swamp eel's presence were detected during the 11 years we studied this species, nor was there any evidence that it makes overland movements. Based on these data and observations, the swamp eel in Florida is best described as an illegally introduced, opportunistic and successful predator that feeds on a variety of small prey; fortunately, however, it is unlikely to perpetrate major ecological or economic disturbances.
KEYWORDS:
exotic fishes; fecundity; fish populations; food habits; lower lethal temperature fishes

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(2010) Shetty, K.G., Minnis, A.M., Rossman, A.Y. and Jayachandran, K. The Brazilian peppertree seed-borne pathogen, Neofusicoccum batangarum, a potential biocontrol agent. Biological Control 56(1), 91-97.

 

ABSTRACT
The invasive exotic Brazilian peppertree, Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) has become a serious threat to the delicate ecosystem of Everglades National Park in Florida, USA. More than 4000 ha in the Hole-in-the-Donut (HID) area within the park have been infested with Brazilian peppertree. Brazilian peppertree is a prolific seed producer, which enhances its invasive potential. Native phytopathogens can be a viable tool in the management of exotic species; no prior studies have reported on the occurrence of native seed-borne pathogens of Brazilian peppertree in Florida. This study showed that drupes of Brazilian peppertree are affected by seed-borne fungal pathogens. These fungal pathogens either cause germination failure or attack seedlings after germination, which results in reduced vigor or seedling death. The seed-borne fungal isolate BPSPF-1 was found to be virulent, and when inoculated it was able to kill Brazilian peppertree seedlings in seedling assays, and 1 year old saplings in greenhouse trials. Field inoculation of Brazilian peppertree branches with BPSPF-1 resulted in dieback symptoms. Host range studies on one related native species (winged sumac, Rhus copallinum) and one non-native species (mango, Mangifera indica) showed that neither was affected by girdle inoculation of stems. The BPSPF-1 isolate produced dark melanized mycelium on agar media and did not produce conidia or other fruiting structures. Based on ITS DNA sequence analyses, the isolate was identified as Neofusicoccum batangarum.
KEYWORDS:
Botryosphaeriaceae; Dieback; Fungi; Germination; Neofusicoccum batangarum; Schinus terebinthifolius; Seed-borne schinus-terebinthifolius; biological-control; propagule pressure; florida; infection; plants; colonization; restoration; recruitment; viability

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(2010) Slocum, M.G., Beckage, B., Platt, W.J., Orzell, S.L. and Taylor, W. Effect of Climate on Wildfire Size: A Cross-Scale Analysis. Ecosystems 13(6), 828-840.

 

ABSTRACT
Theory predicts that wildfires will encounter spatial thresholds where different drivers may become the dominant influence on continued fire spread. Studying these thresholds, however, is limited by a lack of sufficiently detailed data sets. To address this problem, we searched for scale thresholds in data describing wildfire size at the Avon Park Air Force Range, south-central Florida. We used power-law statistics to describe the "heavy-tail" of the fire size distribution, and quantile regression to determine how the edges of data distributions of fire size were related to climate. Power-law statistics revealed a heavy-tail, a pattern consistent with scale threshold theory, which predicts that large fires will be rare because only fires that cross all thresholds will become large. Results from quantile regression suggested that different climate conditions served as critical thresholds, influencing wildfire size at different spatial scales. Modeling at higher quantiles (a parts per thousand yen75th) implicated drought as driving the spread of larger fires, whereas modeling at lower quantiles (a parts per thousand currency sign25th) implicated that wind governed the spread of smaller fires. Fires of intermediate size were negatively associated with relative humidity. Our results are consistent with the idea that fire spread involves scale thresholds, with the small-scale drivers allowing fires to spread after ignition, but with further spread only being possible when large-scale drivers are favorable. These results suggest that other data sets that have heavy-tailed distributions may contain patterns generated by scale thresholds, and that these patterns may be revealed using quantile regression.
KEYWORDS:
wildfire size; cross-scale interactions; scale thresholds; quantile regression; power-law statistics; climate everglades-national-park; fire regimes; regression quantiles; united-states; florida; nonlinearities; distributions; complexity; ecology; law

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(2010) Slowey, A.J. Rate of formation and dissolution of mercury sulfide nanoparticles: The dual role of natural organic matter. Geochimica Et Cosmochimica Acta 74(16), 4693-4708.

 

ABSTRACT
Mercury is a global contaminant of concern due to its transformation by microorganisms to form methylmercury, a toxic species that accumulates in biological tissues. The effect of dissolved organic matter (DOM) isolated from natural waters on reactions between mercury(II) (Hg) and sulfide (S(-II)) to form HgS(s) nanoparticles across a range of Hg and S(-II) concentrations was investigated. Hg was equilibrated with DOM, after which S(-II) was added. Dissolved Hg (Hg-aq) was periodically quantified using ultracentrifugation and chemical analysis following the addition of S(-II). Particle size and identity were determined using dynamic light scattering and X-ray absorption spectroscopy. S(-II) reacts with Hg to form 20 to 200 nm aggregates consisting of 1-2 nm HgS(s) subunits that are more structurally disordered than metacinnabar in the presence of 2 x 10(-9) to 8 x 10(-6) M Hg and 10 (mg C) L-1 DOM. Some of the HgS(s) nanoparticle aggregates are subsequently dissolved by DOM and (re)precipitated by S(-II) over periods of hours to clays. At least three fractions of Hg-DOM species were observed with respect to reactivity toward S(-II): 0.3 mu mol reactive Hg per mmol C (60 percent), 0.1 mu mol per mmol C (20 percent) that are kinetically hindered, and another 0.1 mu mol Ha per mmol C (20 percent) that are inert to reaction with S(-II). Following an initial S(-II)-driven precipitation of HgS(s), HgS(s) was dissolved by DOM or organic sulfur compounds. HgS(s) formation during this second phase was counterintuitively favored by lower S(-II) concentrations, suggesting surface association of DOM moieties that are less capable of dissolving HgS(s). DOM partially inhibits HgS(s) formation and mediates reactions between Hg and S(-II) such that HgS(s) is susceptible to dissolution. These findings indicate that Hg accessibility to microorganisms could be controlled by kinetic (intermediate) species in the presence of S(-II) and DOM, undermining the premise that equilibrium Ha species distributions should correlate to the extent or rate of Hg methylation in soils and sediments.
KEYWORDS:
ray-absorption-spectroscopy; fluorescence correlation spectroscopy; aquatic humic substances; methylmercury production; physicochemical heterogeneity; diffusion-coefficients; electrolyte-solutions; florida everglades; methylation rates; marine-sediments

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(2010) Soloviev, A., Gilman, M., Young, K., Brusch, S. and Lehner, S. Sonar Measurements in Ship Wakes Simultaneous With TerraSAR-X Overpasses. IEEE Transactions on Geoscience and Remote Sensing 48(2), 841-851.

 

ABSTRACT
A pilot experiment was conducted in the period from April to June 2008 in the Straits of Florida near Port Everglades, Florida, in order to study the dynamics of far wakes of ships. In this experiment, a small boat with downward-looking sonar made "snakelike" sections through wakes of ships of opportunity during the TerraSAR-X overpasses. The ship and its parameters (length, speed, course, etc.) were identified utilizing an automated identification system. The sonar responded to the clouds of microbubbles generated in the ship wake by the propulsion system and ship-hull turbulence. The ship wakes were traced in the sonar signal typically from 10 to 30 min after the ship's passage. A preliminary analysis of the measurements suggests that the visibility of the centerline ship wake in synthetic aperture radar (SAR) images is correlated with the presence of microbubbles in the wake. This supports the hypothesis that natural surfactants scavenged and brought to the surface by rising bubbles play an important role in the wake visibility in SAR. The influence of the wind-wave field on the ship wake, as well as the effect of screening of the wind-wave field by the ship's hull, adds another level of complexity to wake patterns observed in SAR images.
KEYWORDS:
Geophysical measurements; remote sensing; sonar imaging; synthetic aperture radar (SAR) sar images; surface

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(2010a) South Florida Water Management District, S. DBHYDRO: http://www.sfwmd.gov/dbhydroplsql/show_dbkey_info_main_menu.

 

ABSTRACT (none)
KEYWORDS:

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(2010b) South Florida Water Management District, S. SFER'10 (SoFL Environmental Report), Chapter 11: Kissimmee Basin. SFWMD, West Palm Beach, FL, http://www.sfwmd.gov/portal/page/portal/pg_grp_sfwmd_sfer/portlet_sfer/tab2236037/2010%20report/v1/chapters/v1_ch11.pdf.

 

ABSTRACT (none)
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(2010) Stevens, J.T. and Beckage, B. Fire Effects on Demography of the Invasive Shrub Brazilian Pepper (Schinus terebinthifolius) in Florida Pine Savannas. Natural Areas Journal 30(1), 53-63.

 

ABSTRACT
Fire is a common disturbance in savanna ecosystems that may either facilitate or impede non-native plant invasions. Although fire can create recruitment opportunities for non-native plants, it can also prevent their invasion if it exerts strong negative effects on their demographic processes. Some savannas may, therefore, be able to resist invasion provided the natural, frequent-fire regime remains intact. We examined the effects of fire on the demography of the invasive shrub Brazilian pepper, Schinus terebinthifolius Raddi., which is invading fire-prone slash pine savannas of southern Florida. We studied survivorship, growth, and reproduction of low-density populations of Brazilian pepper in a pine savanna within Everglades National Park to investigate whether fire might suppress Brazilian pepper in the early stages of invasion. We found a significant decrease in Brazilian pepper survivorship following fire, particularly among small individuals. We further found that fire reduced fecundity of surviving Brazilian pepper individuals for at least two years. However, resprouting individuals that survived fire had high relative growth rates the following year, which could facilitate population recovery during inter-fire periods. We used a simple population simulation to show that a low-density cohort of Brazilian pepper may be rapidly eliminated from pine savannas with fire-return intervals of four years or less, but individuals may persist for > 50 years with fire-return intervals of eight years or more. Our study suggests the need to maintain the historical frequent-fire regime in pine savannas in order to prevent their invasion by fire-intolerant shrubs such as Brazilian pepper.
KEYWORDS:
demography; fire; invasion; pine savanna; Schinus terebinthifolius northern australia; persistence niche; everglades; plants; regimes; disturbance; impacts; forests; weed

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(2010) Stoffella, S.L., Ross, M.S., Sah, J.P., Price, R.M., Sullivan, P.L., Cline, E.A. and Scinto, L.J. Survival and growth responses of eight Everglades tree species along an experimental hydrological gradient on two tree island types. Applied Vegetation Science 13(4), 439-449.

 

ABSTRACT
Questions: How are the early survival and growth of seedlings of Everglades tree species planted in an experimental setting on artificial tree islands affected by hydrology and substrate type? What are the implications of these responses for broader tree island restoration efforts? Location: Loxahatchee Impoundment Landscape Assessment (LILA), Boynton Beach, Florida, USA. Methods: An experiment was designed to test hydrological and substrate effects on seedling growth and survivorship. Two islands-a peat and a limestone-core island representing two major types found in the Everglades-were constructed in four macrocosms. A mixture of eight tree species was planted on each island in March of 2006 and 2007. Survival and height growth of seedlings planted in 2006 were assessed periodically during the next two and a half years. Results: Survival and growth improved with increasing elevation on both tree island substrate types. Seedlings' survival and growth responses along a moisture gradient matched species distributions along natural hydrological gradients in the Everglades. The effect of substrate on seedling performance showed higher survival of most species on the limestone tree islands, and faster growth on their peat-based counterparts. Conclusions: The present results could have profound implications for restoration of forests on existing landforms and artificial creation of tree islands. Knowledge of species tolerance to flooding and responses to different edaphic conditions present in wetlands is important in selecting suitable species to plant on restored tree islands
KEYWORDS:
Ground and surface water dynamic; Plant-soil interaction; Soil-water interaction; Substrate type; Tree islands; Wetland restoration floodplain; botswana

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(2010) Swain, E. and Decker, J. Measurement-derived Heat-budget Approaches for Simulating Coastal Wetland Temperature with a Hydrodynamic Model. Wetlands 30(3), 635-648.

 

ABSTRACT
Numerical modeling is needed to predict environmental temperatures, which affect a number of biota in southern Florida, U.S.A., such as the West Indian manatee (Trichechus manatus), which uses thermal basins for refuge from lethal winter cold fronts. To numerically simulate heat-transport through a dynamic coastal wetland region, an algorithm was developed for the FTLOADDS coupled hydrodynamic surface-water/ground-water model that uses formulations and coefficients suited to the coastal wetland thermal environment. In this study, two field sites provided atmospheric data to develop coefficients for the heat flux terms representing this particular study area. Several methods were examined to represent the heat-flux components used to compute temperature. A Dalton equation was compared with a Penman formulation for latent heat computations, producing similar daily-average temperatures. Simulation of heat-transport in the southern Everglades indicates that the model represents the daily fluctuation in coastal temperatures better than at inland locations; possibly due to the lack of information on the spatial variations in heat-transport parameters such as soil heat capacity and surface albedo. These simulation results indicate that the new formulation is suitable for defining the existing thermohydrologic system and evaluating the ecological effect of proposed restoration efforts in the southern Everglades of Florida.
KEYWORDS:
Computational methods; Evapotranspiration; Heat transport; Surface water long-wave radiation; empirical method; evapotranspiration; transport; skies; clear; flow

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(2010) Tamea, S., Muneepeerakul, R., Laio, F., Ridolfi, L. and Rodriguez-Iturbe, I. Stochastic description of water table fluctuations in wetlands. Geophysical Research Letters 37(

 

ABSTRACT
Wetlands are crucial ecosystems which provide several functions, beneficial both to human beings and to the environment. Despite such importance, quantitative approaches to many aspects of wetlands are far from being adequate, above all the interaction between rainfall, vegetation, soil moisture and groundwater depth. Starting from a previously developed model for below-ground stochastic water level fluctuations, we extend it to consider the case of waterlogging. The extended model is now suitable for describing the long-term probability distribution of water table depth in temporarily inundated wetland sites, whose hydrologic input is dominated by stochastic rainfall. The extended model performs well when compared to real data collected in the Everglades National Park (Florida, US), confirming its capability to capture the stochastic variability of wetland ecosystems. Citation: Tamea, S., R. Muneepeerakul, F. Laio, L. Ridolfi, and I. Rodriguez-Iturbe (2010), Stochastic description of water table fluctuations in wetlands
KEYWORDS:

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(2010) Tian, H.Q., Xu, X.F., Miao, S.L., Sindhoj, E., Beltran, B.J. and Pan, Z.J. Modeling ecosystem responses to prescribed fires in a phosphorus-enriched Everglades wetland: I. Phosphorus dynamics and cattail recovery. Ecological Modelling 221(9), 1252-1266.

 

ABSTRACT
We have developed and applied a process-based model, the Wetland Ecosystem Model (WEM), to evaluate the effects of a prescribed fire on the phosphorus (P) dynamics and cattail (Typha domingensis) growth in a P-enriched area in the Florida Everglades. The WEM couples major ecosystem processes including carbon (C), nitrogen (N) and P biogeochemical cycles, plant growth, hydrology, and fire disturbance. The model is used to assess the effects of a prescribed fire on P dynamics and cattail growth through dynamic interaction among four modules: fire, water chemistry, soil, and vegetation. The simulation results are in agreement with observed data including cattail above- and belowground biomass and dead mass, P concentration in surface-water, pore-water, and soil, and soil and water temperature. Cattail above-ground biomass reached the unburned level one year after burn; belowground biomass recovered to unburned level one and half years after the fire, however, dead mass did not completely reach unburned level two years after fires. The fire increased water and soil temperatures in the short term, while indirectly increasing the sensitivity of water and soil temperature post-fire response to air temperature by altering the energy exchange between air and water through a canopy gap created by fire. The fire also altered the P dynamics in surface-water and pore-water. A post-fire P pulse that lasted for less than one month was observed in surface-water. A similar P pulse, but in a small magnitude and a longer duration, was also observed in the pore-water total phosphorus (TP), and then came back to normal level after approximately three months. No significant changes in soil TP was observed during the study period. Meanwhile, no significant changes in water nutrients were observed downstream of the study plot. This finding indicated that the P-enriched wetlands in Everglades act as a buffer in regulating the P concentration in surface-water. Our study showed that the distance of fire effects on a 300 m x 300 m plot was less than 300 m downstream. Sensitivity analysis identified that the air temperature and hydrological conditions are two important driving factors which may alter the cattail community dynamics in response to prescribed fires. Similar to the filed studies, this study provided evidences that fire played an important role in managing plant growth and P dynamics in the Florida Everglades.
KEYWORDS:
Cattail; Everglades; Fire; Phosphorus; Wetland Ecosystem Model (WEM) simulation-model; carbon dynamics; nutrient; soil

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(2010) Todd, M.J., Muneepeerakul, R., Pumo, D., Azaele, S., Miralles-Wilhelm, F., Rinaldo, A. and Rodriguez-Iturbe, I. Hydrological drivers of wetland vegetation community distribution within Everglades National Park, Florida. Advances in Water Resources 33(10), 1279-1289.

 

ABSTRACT
The influence of hydrological dynamics on vegetation distribution and the structuring of wetland environments is of growing interest as wetlands are modified by human action and the increasing threat from climate change. Hydrological properties have long been considered a driving force in structuring wetland communities. We link hydrological dynamics with vegetation distribution across Everglades National Park (ENP) using two publicly available datasets to study the probability structure of the frequency, duration, and depth of inundation events along with their relationship to vegetation distribution. This study is among the first to show hydrologic structuring of vegetation communities at wide spatial and temporal scales, as results indicate that the percentage of time a location is inundated and its mean depth are the principal structuring variables to which individual communities respond. For example, sawgrass, the most abundant vegetation type within the ENP, is found across a wide range of time inundated percentages and mean depths. Meanwhile, other communities like pine savanna or red mangrove scrub are more restricted in their distribution and found disproportionately at particular depths and inundations. These results, along with the probabilistic structure of hydropatterns, potentially allow for the evaluation of climate change impacts on wetland vegetation community structure and distribution.
KEYWORDS:
Everglades; Vegetation; Hydrology; Wetlands landscape; scale; validation; models

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(2010) Toth, L.A. Restoration response of relict broadleaf marshes to increased water depths. Wetlands 30(2), 263-274.

 

ABSTRACT
Broadleaf marsh once covered much of the wetland landscape along the Kissimmee River in central Florida, USA, but is currently restricted to remnant portions of the channelized floodplain that have been subjected to much shallower depths. The initial phase of Kissimmee River restoration, which began in 1999, and a prior (1984-1990) demonstration project increased water depths in several relict broadleaf marshes on the floodplain. Effects of restored water depth regimes on characteristics of these altered broadleaf marsh communities were evaluated. As expected, plant species richness consistently declined in marshes with increased water depth, but cover of signature broadleaf species, Sagittaria lancifolia and Pontederia cordata, exhibited variable responses to restored hydrology. In one marsh mean cover of Sagittaria and Pontederia increased from 32 to 62% following a 37 cm increase in mean annual depths; however, in another relict marsh that underwent a similar increase in hydroperiods and depths, mean cover of these species remained below 30% and Panicum hemitomon persisted as a dominant species. Moreover, invasion of the exotic wetland shrub, Ludwigia peruviana, appears to pose a threat to successful restoration of broadleaf marshes on the Kissimmee floodplain.
KEYWORDS:

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(2010) Troxler, T.G. and Childers, D.L. Biogeochemical Contributions of Tree Islands to Everglades Wetland Landscape Nitrogen Cycling During Seasonal Inundation. Ecosystems 13(1), 75-89.

 

ABSTRACT
In the Florida Everglades, tree islands are conspicuous heterogeneous elements in the herbaceous wetland landscape. We characterized the biogeochemical role of a seasonally flooded tree island during wet season inundation, specifically examining hydrologically mediated flows of nitrogen (N) and N retention by the tree island. We estimated ecosystem N standing stocks and fluxes, soil and litter N transformation rates, and hydrologic fluxes of N to quantify the net ecosystem N mass flux. Results showed that hydrologic sources of N were dominated by surface water loads of nitrate (NO3) and ammonium (NH4). Nitrate immobilization by soils and surficial leaf litter was an important sink for surface water dissolved inorganic N (DIN). We estimated that the net annual DIN retention by a seasonally flooded tree island was 20.5 +/- 5.0 g m(-2) during wet season inundation. Based on the estimated tree island surface water DIN loading rate, a seasonally flooded tree island retained 76% of imported DIN. As such, seasonally flooded tree islands have the potential to retain 55% of DIN entering the marsh landscape via upstream canal overland flow in the wet season. By increasing reactive surface area and DOC availability, we suggest that tree islands promote convergence of elements that enhance DIN retention. Tree islands of this region are thus important components of landscape-scale restoration efforts that seek to reduce sources of anthropogenic DIN to downstream estuaries.
KEYWORDS:
ecosystem budget; gross mineralization; gross nitrification; denitrification; nitrogen fixation; plant uptake; landscape heterogeneity southern everglades; phosphorus enrichment; florida everglades; fresh-water; reduction-oxidation; aquatic ecosystems; nutrient dynamics; organic-matter; forest stream; land-use

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(2010) Ulrich, P.D. and Sedlak, D.L. Impact of Iron Amendment on Net Methylmercury Export from Tidal Wetland Microcosms.
Environmental Science & Technology
44(19), 7659-7665.

 

ABSTRACT
Tidal wetlands can be important sources of methylmercury (MeHg) in aquatic ecosystems. As a result, wetland restoration could increase MeHg concentrations. Previous research has shown that addition of Fe[II] to wetland sediment can reduce MeHg production by decreasing concentrations of bioavailable Hg complexes with dissolved sulfur species. In this study, the potential for reducing MeHg production via an iron amendment was evaluated in laboratory microcosms that used intact sediments from a tidal marsh in San Francisco Bay. The microcosms were maintained under simulated tidal conditions and amended at four iron doses (0, 180, 360, and 720 g-Fe/m(2)). Two experiments were conducted: one with devegetated sediments and one with live wetland vegetation. Following iron addition to the devegetated sediments, porewater S[-II] concentrations decreased for each dose relative to the control with the average weekly export of MeHg in the surface water decreased by 82% and 89% for the two highest doses, respectively. Despite substantial variability within treatment groups, similar trends were observed for the vegetated microcosms. The results suggest that iron addition has the potential to provide a landscape-scale control on MeHg released by restored tidal wetlands; however, additional research is required to evaluate the efficacy of this approach under field conditions.
KEYWORDS:
atomic fluorescence detection; anoxic estuarine sediment; sulfate-reducing bacteria; fresh-water sediments; mercury methylation; organic-matter; gas-chromatography; florida everglades; salt-marsh; sulfide

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(2010) USEPA. Amended Determination. US-Environmental Protection Agency, Washington, DC.,

 

ABSTRACT
http://www.epa.gov/region4/water/wqs/documents/1_AD_final_version_09_03_10.pdf
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(2010) USEPA, O.o.W. National Pollutant Discharge Elimination System (NPDES) Permit Writers’ Manual. US-Environmental Protection Agency, Washington, DC., 273.

 

ABSTRACT
http://cfpub.epa.gov/npdes/writermanual.cfm?program_id=45
KEYWORDS:

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(2010) Van Houtan, K.S., Bass, O.L., Lockwood, J. and Pimm, S.L. Importance of estimating dispersal for endangered bird management.
Conservation Letters
3(4), 260-266.

 

ABSTRACT
Endangered species recovery plans are frustrated by small, spatially structured populations where understanding the influence of birth, death, and dispersal is difficult. Here we use a spatially explicit, long-term study to describe dispersal in the Cape Sable seaside sparrow (Ammodramus maritimus mirabilis). Since 1990, this species declined > 50%. It occurs as several geographically isolated subpopulations in the Florida Everglades. We characterize dispersal, recognizing that our sampling, as well as the species' distribution, is spatially heterogeneous. The annual movements of juveniles and adults are statistically heavy-tailed. That is, while most individuals are recaptured locally, a significant portion exhibit long-distance dispersal. Individuals move between subpopulations to distances > 30 km. Not accounting for the spatial heterogeneity of sampling or the species range itself underestimates dispersal and can lead to ineffective management decisions. Recovery focused on translocation will be less successful than strategies that protect habitat and increase breeding.
KEYWORDS:
Endangered species; long-distance dispersal; habitat fragmentation; translocation; Everglades National Park sable seaside-sparrow; landscapes; everglades; dynamics; patterns;

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(2010) Wachnicka, A., Gaiser, E., Collins, L., Frankovich, T. and Boyer, J. Distribution of Diatoms and Development of Diatom-Based Models for Inferring Salinity and Nutrient Concentrations in Florida Bay and Adjacent Coastal Wetlands of South Florida (USA). Estuaries and Coasts 33(5), 1080-1098.

 

ABSTRACT
The composition and distribution of diatom algae inhabiting estuaries and coasts of the subtropical Americas are poorly documented, especially relative to the central role diatoms play in coastal food webs and to their potential utility as sentinels of environmental change in these threatened ecosystems. Here, we document the distribution of diatoms among the diverse habitat types and long environmental gradients represented by the shallow topographic relief of the South Florida, USA, coastline. A total of 592 species were encountered from 38 freshwater, mangrove, and marine locations in the Everglades wetland and Florida Bay during two seasonal collections, with the highest diversity occurring at sites of high salinity and low water column organic carbon concentration (WTOC). Freshwater, mangrove, and estuarine assemblages were compositionally distinct, but seasonal differences were only detected in mangrove and estuarine sites where solute concentration differed greatly between wet and dry seasons. Epiphytic, planktonic, and sediment assemblages were compositionally similar, implying a high degree of mixing along the shallow, tidal, and storm-prone coast. The relationships between diatom taxa and salinity, water total phosphorus (WTP), water total nitrogen (WTN), and WTOC concentrations were determined and incorporated into weighted averaging partial least squares regression models. Salinity was the most influential variable, resulting in a highly predictive model (r(apparent)(2)=0.97, r(jackknife)(2)=0.95) that can be used in the future to infer changes in coastal freshwater delivery or sea-level rise in South Florida and compositionally similar environments. Models predicting WTN (r(apparent)(2)=0.75, r(jackknife)(2)=0.46), WTP (r(apparent)(2)=0.75, r(jackknife)(2)= 0.49), and WTOC (r(apparent)(2)=0.79, r(jackknife)(2)=0.57) were also strong, suggesting that diatoms can provide reliable inferences of changes in solute delivery to the coastal ecosystem.
KEYWORDS:
Diatoms; Prediction models; Diversity; Salinity; Nutrients; Florida Bay genus climaconeis berkeleyaceae; water-quality trends; marine diatoms; puerto-rico; suborder raphidineae; community structure; baltic sea; multivariate analyses; eastern australia; inference models

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(2010) Walker, W. Evaluations of alternatives to achieve phosphorus WQBELs in discharges to the Everglades Protection Area. Washington DC,

 

ABSTRACT (none)
http://www.epa.gov/region4/water/wqs/documents/AttachmentHforAD.pdf
KEYWORDS:

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(2010) Walker, W. and Kadlec, R.H. Modeling Phosphorus Dynamics in Everglades Wetlands and Stormwater Treatment Areas. US-EPA,

 

ABSTRACT
Longitudinal gradients in phosphorus (P) stored in the water column, vegetation, and soils develop in the wetlands where inflow P concentrations exceed background levels. Prior to the mid 1990s, the Everglades regional P gradient ranged from 100-200 g L-1 in marsh inflows to background levels of 4-8 g L-1. Subsequent implementation of P controls, including agricultural Best Management Practices (BMPs) and Stormwater Treatment Areas (STAs), reduced the average inflow concentration along the northern edge of the Water Conservations Areas (WCAs) to approximately 33 g L-1 in 2007-2009. Additional P controls are being implemented and further measures beyond those currently planned will be required to restore the entire marsh. This paper describes the evolution and application of relatively simple mass-balance models to simulate P storage and cycling processes along P gradients in the STAs and downstream marsh. The models are practical engineering tools that have been extensively applied to the design of Everglades regional P control plans involving combinations of source controls, water management, reservoirs, and STAs, as well as in simulating P dynamics in natural marshes immediately downstream of treated and untreated discharges.
KEYWORDS:

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(2010) Wang, Q.R. and Li, Y.C. Phosphorus adsorption and desorption behavior on sediments of different origins.
Journal of Soils and Sediments 10(6), 1159-1173.

 

ABSTRACT
The aim of this study was to assess phosphorus-retention (P-ret) capacities via P adsorption (P-ads) and desorption (P-des) by sediments collected from six different sources associated with various origins, physical, and chemical characteristics. Sediment samples were collected in the State of Florida, the USA, from estuary, marine, wetland, canal, river, and lake, respectively. Phosphorus adsorption and desorption for each sediment were evaluated in three types of ambient water, i.e., marine, wetland, and canal, with different rates of phosphate added and then desorbed by chloride (Cl-). Capacities in adsorption and desorption of P by various sediments were evaluated with different isotherm models to compare their potentials and stabilities in P retention. Sediments from the canal and lake had the greatest native adsorbed P and the highest zero equilibrium P concentration. Sediment from the estuary had the highest P adsorption and followed by those from wetland and marine origins, respectively. Phosphorus desorption from sediments by replacing exchangeable P with Cl- (20 mmol L-1 KCl) was obtained from an excellent fit of the data by an exponential growth model of desorption kinetics. The fractions of retained P (P-ret = P-ads -aEuro parts per thousand P-des) were as high as 85-98% in the studied sediments, which displayed strong P retention capacities by all these sediments. High capacities to retain P by sediments from estuary and wetland may play a critical role in buffering some chemical and ecological changes and benefit aquatic eco-environments by preventing P rapid release to the overlying water column.
KEYWORDS:
Adsorption; Desorption; Isotherm; Phosphorus; Retention; Sediment particle-bound phosphorus; solid-phase phosphorus; fresh-water wetlands; lake-sediments; phosphate adsorption; marine-sediments; everglades; sorption; soils; release

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(2010) Watts, D.L., Cohen, M.J., Heffernan, J.B. and Osborne, T.Z. Hydrologic Modification and the Loss of Self-organized Patterning in the Ridge-Slough Mosaic of the Everglades. Ecosystems 13(6), 813-827.

 

ABSTRACT
The ridge-slough landscape of the Everglades (Florida, USA), is characterized by elevated ridges dominated by sawgrass (Cladium jamaicense) interspersed among deeper sloughs dominated by floating, submerged and emergent macrophytes and calcareous periphyton. Interactions among hydrologic conditions (water depth, hydroperiod), plant composition and production, and respiration are hypothesized to create alternative peat accretion equilibria at the point scale, while spatial interactions among patches create regular pattern at the landscape scale. Despite significant research on these interactions, few studies have examined the hypothesis that the ridge-slough landscape consists of spatially coupled alternative stable patch states, and none has used diagnostic indicators thereof to assess landscape resilience to hydrologic change. Dense random sampling of water depths (a proxy for soil elevation) along a gradient of hydrologic impairment of drained to relatively natural to impounded conditions was used to evaluate four predictions related to this hypothesis: (1) bimodal soil elevation distributions show strong fidelity to community type; (2) positive autocorrelation at short distances with negative values at longer distances; (3) strong anisotropy (diagnostic of flow orientation), and spatial structure (diagnostic of the strength of landscape self-organization); and (4) loss of these features with hydrologic modification. Our results support the hypothesis that soil elevations are strongly bimodal and anisotropic in areas with minimal hydrologic impact, and spatial autocorrelation patterns indicate the operation of scale-dependent feedbacks. These metrics change markedly with hydrologic modification, although with differences between drainage and impoundment. Moreover, changes in landform precede associated changes in vegetation, suggesting their utility as diagnostic indicators of landscape degradation and recovery.
KEYWORDS:
biogeomorphology; bi-modality; scale-dependent feedbacks; alternative stable states; peat accretion; patterned landscape cladium-jamaicense; florida everglades; typha-domingensis; water management; national-park; vegetation; landscape; peatland; marsh; restoration

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(2010) Wehle, C.A. Response to the Amended Determination Filed September 3, 2010 - Attachment A (Procedure and Legal Issues). South Florida Water Management District, West Palm Beach, FL, 23.

 

ABSTRACT (none)
http://www.sfwmd.gov/portal/page/portal/xrepository/sfwmd_repository_pdf/2010-11-02%20sfwmd%20response%20to%20epa%209.3.10%20amended%20determination.pdf
KEYWORDS:

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(2010) Wu, C.F., Wu, J.P., Qi, J.G., Zhang, L.S., Huang, H.Q., Lou, L.P. and Chen, Y.X. Empirical estimation of total phosphorus concentration in the mainstream of the Qiantang River in China using Landsat TM data. International Journal of Remote Sensing 31(9), 2309-2324.

 

ABSTRACT
Eutrophication is a serious environmental problem in Qiantang River, the largest river in the Zhejiang Province of southeast China. Increased phosphorus concentration is thought to be the major cause of water eutrophication. The objective of this study was to develop an empirical remote sensing model using Landsat Thematic Mapper (TM) data to estimate phosphorus concentration and characterize the spatial variability of the phosphorus concentration in the mainstream of Qiantang River. Field water quality data were collected across a spatial gradient along the river and geospatially overlaid with Landsat satellite images. Various statistical regression models were tested to correlate phosphorus concentration with a combination of other water quality indicators and remotely sensed spectral reflectance, including Secchi depth (SD) and chlorophyll-a (Chl-a) concentration. The optimal regression model was subsequently used to map and characterize the spatial variability of the total phosphorus (TP) concentration in the mainstream of Qiantang River. The results suggest that spectral reflectance from the Landsat satellite is spatially and implicitly correlated with phosphorus concentration (R-2 = 0.77). The approach proved to be effective and has the potential to be applied over large areas for water quality monitoring.
KEYWORDS:

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(2010) Wyatt, K.H., Stevenson, R.J. and Turetsky, M.R. The importance of nutrient co-limitation in regulating algal community composition, productivity and algal-derived DOC in an oligotrophic marsh in interior Alaska. Freshwater Biology 55(9), 1845-1860.

 

ABSTRACT
Compared to lakes and streams, we know relatively little about the factors that regulate algae in freshwater wetlands. This discrepancy is particularly acute in boreal regions, where wetlands are abundant and processes related to climate change (i.e. increased permafrost collapse and soil weathering) are expected to increase nutrient inputs into aquatic systems. To investigate how accelerated nutrient inputs might affect algal structure and function in northern boreal wetlands, we added nitrogen, phosphorus and silica to mesocosms in an oligotrophic marsh in interior Alaska. 2. We conducted two in situ mesocosm enrichment experiments during consecutive summer growing seasons, each lasting 24 days. In 2007, we investigated the effects of +N, +P, +Si and +N+P+Si enrichment on benthic algal biomass (chlorophyll-a, ash-free dry mass, biovolume), chemistry (N : P ratio) and community composition. In 2008, we expanded our first experiment to investigate the effects +N+P, +N+Si, +P+Si and +N+P+Si on the same algal parameters as well as productivity (mg C m-2 h-1). 3. In both experiments, we measured water-column dissolved organic carbon (DOC) inside treatment enclosures and related changes in DOC to standing algal biomass. 4. Benthic algal accrual did not increase following 24 days of enrichment with any nutrient alone or with P and Si together (+P+Si), but increased significantly with the addition of N in any combination with P and Si (+N+P, +N+Si, +N+P+Si). 5. Algal productivity (20 mg C m-2 h-1) increased between three- and seven-fold (57-127 mg C m-2 h-1) with the addition of N in combination with any other nutrient (+N+P, +N+Si, +N+P+Si). Water-column DOC concentration was significantly higher inside N-combination treatments compared to the control during each season, and DOC increased linearly with benthic algal biomass in 2007 (r2 = 0.89, P < 0.0001) and 2008 (r2 = 0.74, P < 0.0001). 6. Taxonomic composition of the wetland algal community responded most strongly to N-combination treatments in both seasons. In 2007, there was a significant shift from Euglena and Mougeotia in the control treatment to Chroococcus and Gloeocystis with +N+P+Si enrichment, and in 2008, a Mougeotia-dominated community was replaced by Gloeocystis in the +N+P treatment and by Nitzschia in +N+Si and +N+P+Si treatments. 7. Together, these data provide several lines of evidence for co-limitation, and the central importance of N as a co-limiting nutrient for the wetland algal community. Changes in algal dynamics with increased nutrient concentrations could have important implications for wetland food webs and suggest that algae may provide a functional link between increasing nutrient inputs and altered wetland carbon cycling in this region.
KEYWORDS:
Alaska; algae; climate change; dissolved organic carbon; nutrients; productivity; wetland northwest-territories canada; fresh-water ecosystems; florida everglades; phosphorus enrichment; periphyton responses; northern everglades; chemical limnology; planktonic algae; prairie wetland; climate-change

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(2010) Xu, Y.P. and Jaffe, R. Occurrence, distribution and origin of C-30 cyclobotryococcenes in a subtropical wetland/estuarine ecosystem. Chemosphere 81(7), 918-924.

 

ABSTRACT
A series of C-30 branched isoprenoid hydrocarbons with a cyclobotryococcane skeleton were identified in the Florida Coastal Everglades Ecosystem Nine such C-30 alkenes were detected and identified as five-membered ring monocyclic hydrocarbons with an identical parent structure of 7 11-cyclobotryococcane based on their mass spectra and hydrogenation behavior Previous reports have suggested Botryococcus Braunu or green sulfur bacteria (Chlorobiaceae) as likely sources of these 7 11-cyclobotryococcanes However their enriched delta C-13 values (about -18%) determined in this study and their absence in freshwater marsh environments of the Everglades suggest that an origin from green sulfur bacteria or possibly mar me diatoms is more likely The depth profile of individual C-30 cyclobotryococcenes in one sediment core from Florida Bay shows abundant variations in their historical deposition and may indicate long-term changes of their source strength due to variations in local environmental conditions (C) 2010 Elsevier Ltd All rights reserved
KEYWORDS:
C-30 cyclobotryococcenes; Diatoms; Green sulfur bacteria; Florida Bay diatom rhizosolenia-setigera; branched isoprenoid alkenes; organic-matter; florida bay; monocyclic alkenes; haslea-ostrearia; marine diatom; sediments; hydrocarbons; c-25

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(2010) Yamashita, Y., Scinto, L.J., Maie, N. and Jaffe, R. Dissolved Organic Matter Characteristics Across a Subtropical Wetland's Landscape: Application of Optical Properties in the Assessment of Environmental Dynamics. Ecosystems 13(7), 1006-1019.

 

ABSTRACT
Wetlands are known to be important sources of dissolved organic matter (DOM) to rivers and coastal environments. However, the environmental dynamics of DOM within wetlands have not been well documented on large spatial scales. To better assess DOM dynamics within large wetlands, we determined high resolution spatial distributions of dissolved organic carbon (DOC) concentrations and DOM quality by excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC) in a subtropical freshwater wetland, the Everglades, Florida, USA. DOC concentrations decreased from north to south along the general water flow path and were linearly correlated with chloride concentration, a tracer of water derived from the Everglades Agricultural Area (EAA), suggesting that agricultural activities are directly or indirectly a major source of DOM in the Everglades. The optical properties of DOM, however, also changed successively along the water flow path from high molecular weight, peat-soil and highly oxidized agricultural soil-derived DOM to the north, to lower molecular weight, biologically produced DOM to the south. These results suggest that even though DOC concentration seems to be distributed conservatively, DOM sources and diagenetic processing can be dynamic throughout wetland landscapes. As such, EEM-PARAFAC clearly revealed that humic-enriched DOM from the EAA is gradually replaced by microbial- and plant-derived DOM along the general water flow path, while additional humic-like contributions are added from marsh soils. Results presented here indicate that both hydrology and primary productivity are important drivers controlling DOM dynamics in large wetlands. The biogeochemical processes controlling the DOM composition are complex and merit further investigation.
KEYWORDS:
dissolved organic matter; dissolved organic carbon; fluorescence characteristics; excitation-emission matrix; parallel factor analysis; spatial distribution; wetlands; Everglades parallel factor-analysis; excitation-emission matrix; florida everglades; fluorescence spectroscopy; chemical-characterization; okavango delta; south florida; humic acids; land-use; carbon

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(2010) Ye, R.Z. and Wright, A.L. Multivariate analysis of chemical and microbial properties in histosols as influenced by land-use types. Soil & Tillage Research 110(1), 94-100.

 

ABSTRACT
The histosols of the Everglades agricultural area in South Florida, USA, were drained in early 1900s and converted from wetlands to agricultural use, which subsequently increased soil oxidation and altered soil properties. The objectives of this study were to determine land-use effects on integrated soil chemical properties and how their discriminations regulate microbial community composition and function using multivariate analytical methods. Soil was collected from sugarcane, cypress, and uncultivated sites. Cluster analysis (CA) and discriminant analysis (DA) were applied to determine differences in soil chemistry and microbial community structure and function, while principal components analysis (PCA) was used to reduce variables. Canonical correlation analysis (CCA) evaluated dependent relationships between soil chemical and microbial parameters. Soils under different land-uses were perfectly clustered into their own groups, which was distinguished by labile inorganic P and total P. Discriminations on integrated soil microbial characteristics were significant. Microbial biomass C and N, community-level physiological profile components, and potentially mineralizable N contributed most to such differentiations. Canonical correlations between soil chemical and microbial indexes were significant on both canonical variates (R-1 = 0.91, p = 0.0006; R-2 = 0.65, p = 0.03). Cumulatively, 63% of the variances in microbial indices were explained by chemical canonical variates. Agricultural management, especially historic P fertilization, altered soil nutrient availability and consequently modified the microbial community composition and function. Future land-use changes and management should consider the role of labile P on the functioning of microbial communities and their control of nutrient cycling since this parameter had the most influence on changing soil properties. (C) 2010 Elsevier B.V. All rights reserved.
KEYWORDS:
Everglades; Land-use; Microbial community; Cluster analysis; Discriminant analysis; Canonical correlation analysis everglades agricultural area; organic nitrogen mineralization; subtropical wetland; community structure; soil; diversity; discrimination; subsidence; fractions; sugarcane

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(2010a) Ye, R.Z., Wright, A.L., McCray, J.M., Reddy, K.R. and Young, L. Sulfur-induced changes in phosphorus distribution in Everglades Agricultural Area soils. Nutrient Cycling in Agroecosystems 87(1), 127-135.

 

ABSTRACT
Elemental S is used as an amendment for Everglades Agricultural Area soils of south Florida to decrease pH and increase P availability to crops. Our objectives were to determine how S application altered phosphorus distribution and availability in organic soils under sugarcane cultivation. Soils were sampled four times during the growing season at 2, 6, 9, and 13 months after sulfur application and subjected to chemical P fractionation. Sulfur application had minimal effect on soil pH and thus generally failed to increase P supply to sugarcane during the entire growing season at the application rates tested due to the high soil buffering capacity against acidification. Yet, a significant reduction in soil pH did increase P concentrations in labile P and Fe-Al bound P fractions at 2 months for the highest S rate. Concentrations of labile P and Fe-Al bound P declined during the sugarcane growing season. The size of Ca-P fraction remained unchanged during the early season but significantly decreased at the end of the growing season. Humic-fulvic acid P fluctuated seasonally, averaging 143, 172, 139, and 181 mg P kg(-1) for 2, 6, 9, and 13 months, respectively. Residual P fluctuated in a contrasting pattern to humic-fulvic acid P and contributed approximately 50% to the total P. Overall, S application did not result in large P accumulation in labile pools, thus S application does not appear to enhance potential P export from fields into wetlands.
KEYWORDS:
Everglades Agricultural Area; Histosol; Phosphorus fractionation; Sulfur; Sugarcane calcareous soils; elemental sulfur; ph; fractionation; subsidence; sugarcane; histosols; phosphate; aluminum

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(2010b) Ye, R.Z., Wright, A.L., Orem, W.H. and McCray, J.M. Sulfur Distribution and Transformations in Everglades Agricultural Area Soil as Influenced by Sulfur Amendment. Soil Science 175(6), 263-269.

 

ABSTRACT
Nutrient export from the Everglades Agricultural Area (EAA) has been implicated in causing sulfur (S) enrichment of Everglades wetlands. However, quantification of the S budget and transformations in EAA soils is inadequate. The objective of this study was to quantify various S fractions and investigate how elemental S amendment affects S dynamics in EAA soils. Reduced S compounds were not detected in soil before elemental S application. Organic S was the major form of S, comprising 87% of total S, followed by extractable SO4-S (13%). Extractable SO4-S for soils receiving 448 kg S ha(-1) was 36%, 131%, 201%, and 270% higher than for unamended soils at 2, 6, 9, and 13 months, respectively. Elemental S was significantly higher in soils receiving 448 kg S ha(-1) (482 mg kg(-1)) than in soils receiving 224 (111 mg kg(-1)) and 112 kg S ha(-1) (55 mg kg(-1)) and unamended soil (0 mg kg(-1)) at 2 months after S application. Similar to extractable SO4-S, elemental S significantly decreased during the growing season. Sulfur application did not affect the sulfatase activity, however, mineralizable S increased concurrently with S application rate, and the effects continued throughout the growing season. This result was largely attributed to the oxidation of the applied elemental S. Our results suggest that large-scale S application in the EAA soils is likely to increase SO42- concentrations in soils, which poses a potential risk of SO42- export to sensitive Everglades wetlands.
KEYWORDS:
Sulfur fractions; everglades; Everglades Agricultural Area; histosols organic sulfur; arylsulfatase activity; consecutive harvests; elemental sulfur; fractions; florida; mineralization; dynamics; availability; oxidation

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(2010) Yu, R.Q., Adatto, I., Montesdeoca, M.R., Driscoll, C.T., Hines, M.E. and Barkay, T. Mercury methylation in Sphagnum moss mats and its association with sulfate-reducing bacteria in an acidic Adirondack forest lake wetland. Fems Microbiology Ecology 74(3), 655-668.

 

ABSTRACT
Processes leading to the bioaccumulation of methylmercury (MeHg) in northern wetlands are largely unknown. We have studied various ecological niches within a remote, acidic forested lake ecosystem in the southwestern Adirondacks, NY, to discover that mats comprised of Sphagnum moss were a hot spot for mercury (Hg) and MeHg accumulation (190.5 and 18.6 ng g-1 dw, respectively). Furthermore, significantly higher potential methylation rates were measured in Sphagnum mats as compared with other sites within Sunday Lake's ecosystem. Although MPN estimates showed a low biomass of sulfate-reducing bacteria (SRB), 2.8 x 104 cells mL-1 in mat samples, evidence consisting of (1) a twofold stimulation of potential methylation by the addition of sulfate, (2) a significant decrease in Hg methylation in the presence of the sulfate reduction inhibitor molybdate, and (3) presence of dsrAB-like genes in mat DNA extracts, suggested that SRB were involved in Hg methylation. Sequencing of dsrB genes indicated that novel SRB, incomplete oxidizers including Desulfobulbus spp. and Desulfovibrio spp., and syntrophs dominated the sulfate-reducing guild in the Sphagnum moss mat. Sphagnum, a bryophyte dominating boreal peatlands, and its associated microbial communities appear to play an important role in the production and accumulation of MeHg in high-latitude ecosystems.
KEYWORDS:
Hg methylation; Sphagnum moss mats; sulfate-reducing bacteria; acidic Adirondack lake wetland gradient gel-electrophoresis; multiple sequence alignment; fresh-water sediments; desulfovibrio-desulfuricans; florida everglades; new-york; molecular characterization; oxidizing bacteria; littoral sediment; microbial ecology

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(2010) Zhang, C.B., Wang, J., Liu, W.L., Zhu, S.X., Ge, H.L., Chang, S.X., Chang, J. and Ge, Y. Effects of plant diversity on microbial biomass and community metabolic profiles in a full-scale constructed wetland. Ecol. Engineering. 36(1), 62-68.

 

ABSTRACT
There has been less understanding of relations of microbial community patterns with plant diversity in constructed wetlands. We conducted a single full-scale subsurface vertical flow constructed wetland (SVFCW, 1000 m2) study focusing on domestic wastewater processing. This study measured the size and structure of microbial community using fumigation extraction and BIOLOG Ecoplate techniques, to examine the effects of macrophyte diversity on microbial communities that are critical in treatment efficiency of constructed wetlands. We also determined the relationship of plant diversity (species richness) with its biomass production under disturbance of the same wastewater supply. Linear regression analysis showed that plant biomass production strongly correlated with plant species richness (R = 0.407, P < 0.001). Increase in plant species richness increased microbial biomass carbon and nitrogen (R = 0.494, P < 0.001; R = 0.465, P < 0.001) and utilization of amino acids on Ecoplates (R = 0.235, P = 0.03), but limited the utilization of amine/amides (R = -0.338, P = 0.013). Principal components analysis (PCA) showed that the diversity and community-level physiological profiles (CLPP) of microbial community at 168 h of incubation strongly depended on the presence or absence of plant species in the SVFCW system, but not on the species richness. This is the first step toward understanding relations of plant diversity with soil microbial community patterns in constructed wetlands, but the effect of species diversity on microbial community should be further studied.
KEYWORDS:
Subsurface vertical flow constructed wetland; Plant diversity; Microbial community; CLPP

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(2010) Zheng, W. and Hintelmann, H. Isotope Fractionation of Mercury during Its Photochemical Reduction by Low-Molecular-Weight Organic Compounds. Journal of Physical Chemistry A 114(12), 4246-4253.

 

ABSTRACT
Photochemical reduction of Hg(II) by various low-molecular-weight organic compounds (LMWOC) was investigated to evaluate the effect of specific functional groups that are typically encountered in natural dissolved organic matters (DOM) on the photoreactivity and isotope fractionation of Hg. LMWOC with reduced sulfur functional groups (e.g., cysteine, glutathione) resulted in slower photochemical reduction of Hg(II) than those without reduced sulfur groups (e.g., serine, oxalic acid). Reduction rate constants were specifically determined for two contrasting LMWOC: DL-serine (0.640 h(-1)) and L-cysteine (0.047 h(-1)). Different mass independent isotope effects of Hg were induced by the two types of LMWOC. S-containing ligands specifically enriched magnetic isotopes (Hg-199 and Hg-201) in the product (Hg(0)) while sulfurless ligands enriched Hg-199 and Hg-201 in the reactant (Hg(II)), suggesting that opposite magnetic isotope effects were produced by different types of ligands. The nuclear field shift effect was also observed in the photochemical reduction by serine. These isotope effects are related to specific functional groups and reduction mechanisms, and may be used to distinguish between primary and secondary photochemical reduction mechanisms of Hg(II) and to explain isotope fractionation during the photochemical reduction of Hg(II) by natural DOM, which provides mixed bonding conditions.
KEYWORDS:
dissolved gaseous mercury; magnetic isotope; vapor generation; humic substances; aqueous-solution; photoredox chemistry; florida everglades; chemical-reactions; reduced sulfur; heavy-elements

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(2010) Zweig, C.L. and Kitchens, W.M. The Semiglades: The Collision of Restoration, Social Values, and the Ecosystem Concept.
Restoration Ecology
18(2), 138-142.

 

ABSTRACT
Defining success targets in restoration and how social values affect them are two commonly discussed issues in restoration today. We believe that how success is commonly defined-with vague terms such as "healthy ecosystem" or cited as a return to a previous, historic state-needs to be reevaluated. With the increasing number of novel ecosystems, there is an increasing conflict between the ecosystem concept, social values, and restoration. This arises from the fact that ecosystems are defined by the values of the scientists describing them, necessarily constraining the ecosystem to a generally static concept. It is not directly the concept, but how it is perceived through our filter of social values that represses the creativity and innovation needed in restoration today. Within restoration, we feel that the ecosystem concept does a disservice by ignoring the increasing number of novel systems, and that hinders real progress in a time when hesitation can be costly. To best illustrate this, we offer the example of restoration of the Florida Everglades and how it has become a novel system in pattern and process. We suggest renaming the Everglades "The Semiglades" in hopes of opening a dialog to expose social/ecosystem biases and include novel landscapes in management and planning.
KEYWORDS:
Everglades; novel system; social values; success targets management; ecology; future; time

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(END of year 2010 composite publication LIST)

   

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