Wetland-dependent Species Research Articles

The role of reserves and anthropogenic habitats for functional connectivity and resilience of ephemeral wetlands.

Ecological reserves provide important wildlife habitat in many landscapes, and the functional connectivity of reserves and other suitable habitat patches is crucial for the persistence and resilience of spatially structured populations. To maintain or increase connectivity at spatial scales larger than individual patches, conservation actions may focus on creating and maintaining reserves and/or influencing management on non-reserves. Using a graph-theoretic approach, we assessed the functional connectivity and spatial distribution of wetlands in the Rainwater Basin of Nebraska, USA, an intensively cultivated agricultural matrix, at four assumed, but ecologically realistic, anuran dispersal distances. We compared connectivity in the current landscape to the historical landscape and putative future landscapes, and evaluated the importance of individual and aggregated reserve and non-reserve wetlands for maintaining connectivity. Connectivity was greatest in the historical landscape, where wetlands were also the most densely distributed. The construction of irrigation reuse pits for water storage has maintained connectivity in the current landscape by replacing destroyed wetlands, but these pits likely provide suboptimal habitat. Also, because there are fewer total wetlands (i.e., wetlands and irrigation reuse pits) in the current landscape than the historical landscape, and because the distribution of current wetlands is less clustered than that of historical wetlands, larger and longer dispersing, sometimes nonnative species may be favored over smaller, shorter dispersing species of conservation concern. Because of their relatively low number, wetland reserves do not affect connectivity as greatly as non-reserve wetlands or irrigation reuse pits; however, they likely provide the highest quality anuran habitat. To improve future levels of resilience in this wetland habitat network, management could focus on continuing to improve the conservation status of non-reserve wetlands, restoring wetlands at spatial scales that promote movements of shorter dispersing species, and further scrutinizing irrigation reuse pit removal by considering effects on functional connectivity for anurans, an emblematic and threatened group of organisms. However, broader conservation plans will need to give consideration to other wetland-dependent species, incorporate invasive species management, and address additional challenges arising from global change in social-ecological systems like the Rainwater Basin.

Experimental canopy removal enhances diversity of vernal pond amphibians

Vernal ponds are often treated as protected environments receiving special regulation and management. Within the landscapes where they are found, forest vegetation frequently dominates surrounding uplands and can grow to overtop and shade pond basins. Two bodies of research offer differing views of the role of forest canopy for vernal pond systems. Studies of landscape conversion suggest that removing forest overstory within uplands can cause local extinctions of amphibians by altering terrestrial habitat or hindering movement. Studies of canopy above pond basins imply an opposite relationship; encroachment of overstory vegetation can be associated with local extinctions potentially via changes in light, thermal, and food resource environments. Unresolved uncertainties about the role of forest canopy reveal significant gaps in our understanding of wetland species distributions and dynamics. Any misunderstanding of canopy influences is simultaneously important to managers because current practices emphasize promoting or conserving vegetation growth particularly within buffers immediately adjacent to ponds. We evaluated this apparent contradiction by conducting a landscape-scale, long-term experiment using 14 natural vernal ponds. Tree felling at six manipulated ponds was limited in spatial scope but was nevertheless effective in increasing water temperature. Compared with eight control ponds, manipulated ponds maintained more amphibian species during five years post-manipulation. There was little evidence that any species was negatively influenced, and the reproductive effort of species for which we estimated egg inputs maintained pretreatment population densities in manipulated compared with control ponds. Overall, our experiment shows that a carefully circumscribed reduction of overhead forest canopy can enhance the capacity of vernal ponds to support wildlife diversity and suggests a scale dependence of canopy influences on amphibians. These findings have implications for the connection between current wetland management practices and the goals of wetland stewardship and conservation of wetland-dependent species.

Evidence for 20th century climate warming and wetland drying in the North American Prairie Pothole Region

The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland-dependent species.

Seed bank potential of moist-soil managed wetlands in east-central Texas

Proper management techniques on moist-soil wetlands provide methods for enhancement of established wetlands, restoration of former wetlands, and creation of new wetland habitat. These techniques also create suitable wetland habitat for non-breeding waterfowl and other wetland dependent species during winter. To understand moist-soil managed wetland vegetative patterns, aspects such as plant species distribution, reproductive strategy, seed bank composition and viability should be thoroughly characterized. We investigated soil seed bank potential of moist-soil managed wetlands on Richland Creek Wildlife Management Area, Texas to determine which treatment (i.e., drawdown or flooded) produced the most desirable moist-soil plants. A total of 27 species germinated, producing 3,731 and 3,031 seedlings in drawdown and flooded treatments, respectively. There were also differences in stem densities between treatments of desirable and non-desirable species. Drawdown treatments had more seedlings germinate than flooded treatments, validating the notion that drawdown treatments provide favorable conditions for seed germination. Drawdown and flooding techniques, when properly timed, will allow managers to drive and directly influence managed wetland plant communities based on seed bank composition and response to presence or absence of water during the germination period.

ASSESSMENT OF RIPARIAN VEGETATION SENSITIVITY TO RIVER HYDROLOGY DOWNSTREAM OF A MAJOR TEXAS DAM

Dams may impact the health of downstream riparian vegetation communities through flow modifications such as decreased flood frequency and duration. Without historical vegetation data, however, it is difficult to relate changes in vegetation composition to hydrology patterns downstream of dams. We studied bottomland hardwood forests downstream of Toledo Bend Dam on the Sabine River in Texas and Louisiana to determine their sensitivity to minor changes in river hydrology with a particular focus on floods. Current riparian vegetation was characterized within three topographic zones at three selected sites below the dam. Using 80 years of hydrologic records from two gauging stations downstream of the dam, we evaluated trends in flood frequency, flood duration, peak discharge and total flood discharge in those periods before (1926−1965) and after (1971−2005) dam construction, as well as related flood stage to floodplain elevations to link topography to flood frequency. Plant species diversity in this system is highly dependent on minor changes in elevation, and the proportion of wetland-dependent species changes rapidly with only a few centimeters difference in elevation. Although 50% of trees, shrubs and herbs in the sloughs were wetland adapted, their numbers were only 21% in the levees (74–284 cm higher in elevation) and 14% in the mid-floodplains. Since dam construction, total flood discharge and duration at the most upstream gauge on the Sabine River decreased by 49%. At both gauges, mean discharge was also altered with higher summer flows. Patterns of tree regeneration point to less recruitment by wetland-dependent species in the years following dam construction. These results suggest that minor changes in flood magnitude might limit occurrence of wetland species to the lowest topographic zones and illustrate the need to analyse sensitivity of plants to minor changes in flood characteristics when historical data for the vegetation community are lacking. Copyright © 2012 John Wiley & Sons, Ltd.

Investigation of Great Egret (Casmerodius albus) breeding success in Hara Biosphere Reserve of Iran

Study of Great Egret breeding success was carried out for the first time in Hara Biosphere Reserve of Iran. Since Great Egret is considered as wading bird as well as wetland-dependent species which is located on top of the food chain in this ecosystem, its breeding study is an appropriate means for evaluating food supply fluctuations and environmental threatening factors by comparison of different years. On the other hand, Great Egret is considered a suitable indicator to examination of biological changes, impact of pollutions, and other effective human activities on Hara Biosphere Reserve. Therefore, read-ahead is required for area management planning in order to maintain the health of mangrove ecosystem and control threatening factors of the sensitive biodiversity of area. The results indicate that the average breeding success of Great Egret in different stages of hatching success, fledging success, and breeding success were equal to 0.54, 0.61, and 0.50 in 2008 and 0.61, 0.59, and 0.42 in 2009, respectively.

Prairie Wetland Complexes as Landscape Functional Units in a Changing Climate

The wetland complex is the functional ecological unit of the prairie pothole region (PPR) of central North America. Diverse complexes of wetlands contribute high spatial and temporal environmental heterogeneity, productivity, and biodiversity to these glaciated prairie landscapes. Climatewarming simulations using the new model WETLANDSCAPE (WLS) project major reductions in water volume, shortening of hydroperiods, and less-dynamic vegetation for prairie wetland complexes. The WLS model portrays the future PPR as a much less resilient ecosystem: The western PPR will be too dry and the eastern PPR will have too few functional wetlands and nesting habitat to support historic levels of waterfowl and other wetland-dependent species. Maintaining ecosystem goods and services at current levels in a warmer climate will be a major challenge for the conservation community.

Habitat range of two alpine medicinal plants in a trans-Himalayan dry valley, Central Nepal

Understanding of the habitat range of threatened Himalayan medicinal plants which are declining in their abundance due to high anthropogenic disturbances is essential for developing conservation strategies and agrotechnologies for cultivation. In this communication, we have discussed the habitat range of two alpine medicinal plants, Aconitum naviculare (Bruhl) Stapf and Neopicrorhiza scrophulariiflora (Pennel) Hong in a trans-Himalayan dry valley of central Nepal, Manang district. They are the most prioritized medicinal plants of the study area in terms of ethnomedicinal uses. A. naviculare occurs on warm and dry south facing slopes between 4090∼4650 m asl along with sclerophyllous and thorny alpine scrubs, while N. scrophulariiflora is exclusively found on cool and moist north facing slope between 4000 and 4400 m asl where adequate water is available from snow melt to create a suitable habitat for this wetland dependent species. The soil in rooting zone of the two plants differs significantly in organic carbon (OC), organic matter (OM), total nitrogen (N) and carbon to nitrogen (C/N) ratio. Due to cool and moist condition of N. scrophulariiflora habitat, accumulation of soil OC is higher, but soil N content is lower probably due to slow release from litter, higher leaching loss and greater retention in perennial live biomass of the plant. The C/N ratio of soil is more suitable in A. navuculare habitat than that of N scrophulariiflora for N supply. Warm and sunny site with N rich soil can be suitable for cultivation of A. naviculare, while moist and cool site with organic soil for N. scrophulariiflora. The populations of both the plants are fragmented and small. Due to collection by human and trampling damage by livestock, the population of A. naviculare was found absent in open areas in five of the six sampling sites and it was confined only within the bushes of alpine scrubs. For N. scrophulariiflora, high probability of complete receding of small glaciers may be a new threat in future to its habitat. The information about habitat conditions, together with the information from other areas, can be useful to identify potential habitats and plan for cultivation or domestication of the two medicinal plants.

Spatiotemporal dynamics of complex ecological networks: Power-law scaling and implications for conservation planning

AbstractSpatial constraints on the topology of complex networks are just beginning to be appreciated, both theoretically and in concrete examples like the Internet and global air transportation network. Ecological networks, composed of habitat patches connected by species dispersal, are intrinsically spatial and show promise as a tool for conservation planning; but while habitat-loss effects on ecological networks have been simulated, such effects have not been directly measured in ecological networks varying over time. In this study, I used satellite remote sensing to study ecological networks composed of wetland habitat in the Prairie Pothole Region (PPR) of North America. I find power-law scaling of important topological properties as a function of dispersal ability and as wetland density varies with climate. Prairie wetland networks are 'meso-worlds' with mean topological distance increasing faster with network size than small-world networks, but slower than regular lattices. While similar dynamics have been shown in random spatial networks, these results emphasize the importance of processes determining locations of nodes in a spatial network, with possible implications in other areas like wireless communication networks or disease transmission networks. Wetland networks establish a climate envelope for landscape connectivity in the PPR, and I show that wetland-dependent species face a 'crisis of connectivity' with climate change. The global biodiversity crisis requires that conservation planners act quickly over large areas using limited resources; a network-based approach to coarse-filter conservation planning in dynamic landscapes should be broadly applicable to this problem.

Spatiotemporal dynamics of complex ecological networks: Power-law scaling and implications for conservation planning

AbstractSpatial constraints on the topology of complex networks are just beginning to be appreciated, both theoretically^1-3^ and in concrete examples like the Internet^4^ and global air transportation network^5^. Ecological networks, composed of habitat patches connected by species dispersal, are intrinsically spatial and show promise as a tool for conservation planning; but while habitat-loss effects on ecological networks have been simulated, such effects have not been directly measured in ecological networks varying over time^6-8^. In this study, I used satellite remote sensing to study ecological networks composed of wetland habitat in the Prairie Pothole Region (PPR) of North America. I find power-law scaling of important topological properties as a function of dispersal ability and as wetland density varies with climate. Prairie wetland networks are 'meso-worlds' with mean topological distance increasing faster with network size than small-world networks^9^, but slower than regular lattices^10^. While similar dynamics have been shown in random spatial networks^1,3^, these results emphasize the importance of processes determining locations of nodes in a spatial network, with possible implications in other areas like wireless communication networks^11^ or disease transmission networks^12^. Wetland networks establish a climate envelope for landscape connectivity in the PPR, and I show that wetland-dependent species face a 'crisis of connectivity' with climate change. The global biodiversity crisis requires that conservation planners act quickly over large areas using limited resources^13,14^; a network-based approach to coarse-filter conservation planning in dynamic landscapes should be broadly applicable to this problem.

Cascading food‐web effects of piscivore introductions in shallow lakes

Summary 1. Anthropogenic landscape modifications have resulted in increased water depths and greater connectivity among the remaining shallow lakes throughout eastern portions of the Prairie Pothole Region of North America. This has created conditions favourable for the establishment of planktivorous fish populations, notably fathead minnows Pimephales pr?rnelas. Such fish populations may reach high densities and reduce Zooplankton and macroinvertebrate abundance and diversity. Resulting reductions in algal grazing by Zooplankton favour transition to a turbid-water state, characterized by increased phytoplankton, decreased water clarity, and reduced macrophytes. Ultimately, such lakes are characterized by low habitat complexity and biodiversity, and conditions less favourable for waterbirds and other wetland-dependent species. 2. We conducted a 3-year study to assess the efficacy of walleye Sander vitreus stocking as a means of initiating trophic cascades, thus testing the ecological theory that piscivore addition can promote shifts from the turbid to the clear-water state by suppressing planktivores (fathead minnows), increasing Zooplankton and macroinvertebrates, and reducing phytoplankton. Treatments consisted of six sites stocked with walleye fry, six lakes stocked with walleye age-1 and older, and six control lakes containing antecedent fathead minnows only. 3. Stocking walleye fry resulted in much lower densities of fathead minnows and higher densities of cladocerans and some macroinvertebrates. Chlorophyll a also decreased in the fry treatment sites. Stocking age-1 and older walleye induced few changes at the stocking density we tested. 4. The success of walleye fry appears to be partly attributable to their rapid diet shift to fish prey and their ability to consume and suppress all life stages of planktivores (fry, juveniles, and adults). However, most responses to walleye fry additions were short-lived, indicating that achieving long-term improvements may require repeated restocking. 5. Synthesis and applications. The available evidence indicates that catchment-level restoration alone is often of limited utility in restoring clear-water conditions in shallow lakes. Our results indicated that stocking piscivorous fish has the potential to improve ecological characteristics of shallow lakes, overcoming tendencies towards phytoplankton dominance. We suggest that managers consider using piscivorous fish stocks, ideally in conjunction with catchment-level restoration measures, to stimulate improvement of ecological characteristics in shallow lakes.

Created versus natural wetlands: Avian communities in Virginia salt marshes

Permits to destroy wetlands often require the creation of the same type of wetland elsewhere. An assumption underlying this practice is that such created wetlands will replace the ecological functions lost when the developed wetland was destroyed. Part of this ecological function is providing habitat for wildlife, including, in coastal areas, a suite of bird species tied to salt marshes for some portion of their life cycle. We tested the hypothesis that created wetlands provide habitat for the avian communities lost when wetlands are destroyed by comparing the breeding and wintering birds on 11 small created salt marshes with those on 11 natural reference salt marshes that were carefully matched for size and surrounding land cover. We found that, during the breeding season, created salt marshes had lower avian abundance and richness than reference salt marshes. In particular, wetland-dependent species were poorly represented on created wetlands. On the other hand, bird use outside of the breeding season and use by an important salt marsh obligate species, the clapper rail (Rallus longirostris), did not differ. Created wetlands that we surveyed failed to completely replicate the bird and plant communities that we observed on nearby natural reference salt marshes, raising the question of whether current mitigation policies that encourage wetland creation should continue without further investigation into the success of such wetlands at recreating wildlife habitat.

Aquatic macroinvertebrate assemblages in mitigated and natural wetlands

Many wetlands have been constructed in West Virginia as mitigation for a variety of human disturbances, but no comprehensive evaluation on their success has been conducted. Macroinvertebrates are extremely valuable components of functioning wetland ecosystems. As such, benthic and water column invertebrate communities were chosen as surrogates for wetland function in the evaluation of 11 mitigation and 4 reference wetlands in West Virginia. Mitigation wetlands ranged in age from 4 to 21 years old. Overall familial richness, diversity, density and biomass were similar between mitigation and reference wetlands (p > 0.05). Within open water habitats, total benthic invertebrate density was higher in reference wetlands, but mass of common taxa from water column samples was higher in mitigation wetlands (p < 0.05) Planorbidae density from benthic samples in emergent habitats was higher in reference than mitigated wetlands. Benthic Oligochaeta density was higher across open water habitats in mitigation wetlands. All other benthic taxa were similar between wetland types. Among the most common water column orders, Isopoda density was higher in reference wetlands, but Physidae density was higher in mitigation wetlands. Within mitigation wetlands, emergent areas contained higher richness and diversity than open areas. These data indicate that mitigation and reference wetlands generally support similar invertebrate assemblages, especially among benthic populations. The few observed differences are likely attributable to differences in vegetative community composition and structure. Mitigation wetlands currently support abundant and productive invertebrate communities, and as such, provide quality habitat for wetland dependent wildlife species, especially waterbirds and anurans.

Waterbird use of created wetlands in golf-course landscapes

As human pressures continue to alter and degrade natural wetlands, alternative habitats such as created wetlands may become increasingly important to wetland-dependent species. Golf-course ponds and impoundments in Florida often are used both to store water for irrigation and to prevent extensive flooding during the rainy season. These semipermanent water bodies also may provide habitat for waterbirds. To determine the habitat value of constructed golf-course ponds to waterbirds, we quantified the abundance and diversity of waterbirds using 183 ponds on 12 courses in southwest Florida from January through April 2001 and 2002. We also quantified vegetation and hydrological features of ponds to determine their correlation with waterbird site selection. We recorded 10,474 birds representing 42 species during the 2-year period. We categorized species into 6 foraging guilds, which we used for analyses and management recommendations. In general, results from this study indicate that golf-course ponds are capable of attracting many species of waterbirds. However, analysis of site preference resulted in a wide range of pond features selected by each foraging guild. This finding coupled with low densities of birds (<2 birds/ha for most species) suggested that the value of golf-course ponds may be enhanced through vegetation and hydrological modifications designed to appeal to specific guilds.

Reconstructing Habitat Use and Wetland Nursery Origin of Yellow Perch from Lake Superior using Otolith Elemental Analysis

The use of otolith elemental composition as a natural tag has emerged as a powerful tool for managing and understanding the ecology of marine fish populations. The approach remains relatively untested in fresh waters, so we examined its utility for reconstructing habitat use and wetland nursery origin in Lake Superior. We analyzed the otolith margin of adult yellow perch, Perca flavescens, as an indicator of recently occupied habitat, and the juvenile region of the otolith core as an indicator of nursery area. To characterize elemental fingerprints, all otolith samples were analyzed for Ca and 13 minor and trace elements using mass spectrometry. We found differences in the otolith concentrations of several elements between yellow perch inhabiting coastal wetlands and those inhabiting the adjacent nearshore waters of Chequamegon Bay. The most striking difference was the high concentration of Sr in the sagittal margins of wetland-caught fish relative to those captured in the bay. Based on differences in otolith Sr concentrations alone, fish from bay and wetland habitats could be distinguished with 100% accuracy. We also found that elemental fingerprints derived from otolith cores of adult yellow perch were similar among fish captured from wetlands adjacent to Chequamegon Bay but quite distinct for one site outside of the bay, suggesting these fish came from a separate population from those in Chequamegon Bay. Overall, these results encourage us that elemental fingerprinting techniques will be useful for estimating the relative importance of different coastal wetland habitats to wetland-dependent species in the Great Lakes.

BREEDING SEASON BIRD USE OF RESTORED WETLANDS IN EASTERN MARYLAND

Abstract We evaluated breeding season (May–July) bird species richness, abundance, and diversity in 21 restored wetlands and several associated habitats (woodlots, cultivated and uncultivated fields, and hedgerows) on Maryland's Eastern Shore over two years. Ninety-seven bird species were encountered over all habitats, while 72 of these species were found in wetlands. Of those birds found in wetlands, 35 species (49%) were wetland dependent and 13 species (18%) were breeding. Wetland-dependent, shorebird, and total species richness and bird abundance were lowest in fields and highest in restored wetlands. Total avian abundance and species richness in woodlots were similar to values in restored wetlands, but species composition differed. The density of individuals and of species was highest in hedgerows and restored wetlands. Bird abundance, species richness, and diversity were higher in restored wetlands in the second year of the study. Richness showed no regression relationship (p > 0.05) with either sit...

Assessing avian richness in remnant wetlands: Towards an improved methodology

Because the North American Breeding Bird Survey provides inadequate coverage of wetland habitat, the Wetland Breeding Bird Survey was recently established in Ohio, USA. This program relies on volunteers to conduct 3 counts at each monitored wetland. Currently, all counts are conducted during the morning. Under the premise that volunteer participation could be increased by allowing evening counts, we evaluated the potential for modifying the methodology. We evaluated the sampling efficiency of all 3-count combinations of morning and evening counts using data collected at 14 wetlands. Estimates of overall species richness decreased with increasing numbers of evening counts. However, this pattern did not hold when analyses were restricted to wetland-dependent species or those of conservation concern. Our findings suggest that it would be reasonable to permit evening counts, particularly if the data are to be used to monitor wetland-dependent species and those of concern.

Effects of beaver on the thermal biology of an amphibian

It is often assumed that ecological interactions happen at rapid rates relative to evolutionary change. In this study we examined the development and physiology of an amphibian (Rana sylvatica) from populations found in forested wetlands, and from wetlands that had been cleared by reinvading beaver (Castor canadensis). Embryos from beaver wetlands hatched at lower rates when raised in a shaded, common garden setting compared with embryos from forested wetlands. Larvae from beaver wetlands had higher critical thermal maxima compared with conspecifics from forested wetlands. These patterns suggest that R. sylvatica populations may have diverged rapidly (in less than 36 years) in response to changes in their environment induced by another species. Other agents of thermal change, such as anthropogenic landscape conversion or alteration of global climate, could have analogous impacts on wetland dependent species such as amphibians.

The mount pinatubo eruptions, effects of the atmosphere and climate

Despite prevalent awareness of global amphibian declines, there is still little information on trends for many widespread species. To inform land managers of trends on protected landscapes and identify potential conservation strategies, we collected occurrence data for five wetland-breeding amphibian species in four national parks in the U.S. Rocky Mountains during 2002–2011. We used explicit dynamics models to estimate variation in annual occupancy, extinction, and colonization of wetlands according to summer drought and several biophysical characteristics (e.g., wetland size, elevation), including the influence of North American beaver (Castor canadensis). We found more declines in occupancy than increases, especially in Yellowstone and Grand Teton national parks (NP), where three of four species declined since 2002. However, most species in Rocky Mountain NP were too rare to include in our analysis, which likely reflects significant historical declines. Although beaver were uncommon, their creation or modification of wetlands was associated with higher colonization rates for 4 of 5 amphibian species, producing a 34% increase in occupancy in beaver-influenced wetlands compared to wetlands without beaver influence. Also, colonization rates and occupancy of boreal toads (Anaxyrus boreas) and Columbia spotted frogs (Rana luteiventris) were ⩾2 times higher in beaver-influenced wetlands. These strong relationships suggest management for beaver that fosters amphibian recovery could counter declines in some areas. Our data reinforce reports of widespread declines of formerly and currently common species, even in areas assumed to be protected from most forms of human disturbance, and demonstrate the close ecological association between beaver and wetland-dependent species.

Ecology, hydrology, and advanced wastewater treatment potential of an artificial wetland in North-central, Florida

Two artificial marsh/pond systems with a combined area of 21 ha were studied during a one-year period. Since their construction in 1978, volunteer plant colonization has resulted in a shifting mosaic of cattails (Typha spp.), water pennywort (Hydrocotlyeumbellata), frog’s-bit (Limnobiumspongia), duckweed (Lemna spp.), and other less abundant species. At least 45 bird species were observed to use the wetlands during this study with very dense populations noted for several wetland-dependent species. Alligators, fish, turtles, and snakes were abundant in the ponds. The ponds operate as flow-through systems, receiving an average treated wastewater application of 4.8 cm per week. Mass balances indicated significant percent removals for biochemical oxygen demand (82%), total suspended solids (80%), and total nitrogen (93%). Removal of total phosphorus was lower, averaging 31% over the one year study.