Searching for the Achilles heel(s) for maintaining invertebrate biodiversity across complexes of depressional wetlands

Wetlands are among the most threatened ecosystems worldwide due to climate change and land-use conversion. Regional biodiversity of temporary wetlands is dependent on the existence of habitat complexes with variable hydroperiods. Because temperature and rainfall regimes are predicted to shift globally, together with land-use patterns, different scenarios of wetland loss are expected in the future. To understand how wetland biodiversity might change in the future, it is important to evaluate how the loss of particular hydroperiods will affect overall diversity in a region. Using invertebrate datasets from five wetland complexes distributed across South and North America, we calculated beta diversity metrics for each region. Then we contrasted those metrics to simulations of sequential deletions of subsets (30%) of the long-, moderate- and short-hydroperiod wetlands to assess which wetland class would most affect invertebrate beta diversity in each region. Deletions of the short-hydroperiod wetlands led to the most significant decline in beta diversity. However, deletion effects of different wetland classes varied across study regions, with a negative correlation existing between deletions of the long- and short-hydroperiod wetlands on invertebrate beta diversity. Our simulations indicate that loss of short-hydroperiod wetlands will have the most significant effects on invertebrate beta diversity, but loss of long-hydroperiod wetlands will also be important. Thus, wetlands from both hydroperiod extremes should be considered when assessing potential biodiversity declines associated with habitat loss.     

Biological diversity versus risk for mosquito nuisance and disease transmission in constructed wetlands in southern Sweden

In southern Sweden, many wetlands have been constructed, and maintaining or increasing biological diversity is often included in the aims. Some wetlands are constructed near human settlements, thus raising the problem of wetlands being associated with mosquitoes (Diptera: Culicidae). Increased biodiversity (including mosquito diversity) is considered desirable, whereas mosquito nuisance from a human point of view is not. Adult mosquito abundance, diversity and species assemblages of constructed wetlands were compared to natural wetlands. The potential of constructed wetlands for mosquito nuisance and transmission of mosquito-borne viruses was evaluated. The study areas included five constructed and four natural wetlands. Mosquito abundance and species richness were higher in the natural than in the constructed wetlands, and showed a positive correlation with wetland size. Mosquito species assemblages formed three clusters, which were not explained by origin, size and water permanence of wetlands. In a redundancy analysis, however, mosquito faunas showed significant relationships with these variables, and size and origin of wetlands were most important. Major nuisance species (multivoltine species feeding on mammals and laying eggs on soil) were found in all wetlands, although in relatively low numbers. Risk assessment for Sindbis virus transmission showed moderate risk for two constructed wetlands near human settlements. It is concluded that small size of constructed wetlands has the advantage of low mosquito numbers from a human point of view. The use of functional groups is recommended as a tool for presenting mosquito data to the public, and for helping communication between scientists and administrative decision makers.     

The potential for constructed wetlands for wastewater treatment and reuse in developing countries: a review

Constructed wetlands are among the recently proven efficient technologies for wastewater treatment. Compared to conventional treatment systems, constructed wetlands are low cost, are easily operated and maintained, and have a strong potential for application in developing countries, particularly by small rural communities. However, these systems have not found widespread use, due to lack of awareness, and local expertise in developing the technology on a local basis. This paper summarizes information on current methods used for wastewater treatment in developing countries, and briefly gives basic information on wetlands. The paper further examines the potential of constructed wetlands for wastewater treatment and reuse in developing countries by looking at the results of current research initiatives towards implementation of the technology in these countries. Future considerations in choosing constructed wetlands as wastewater treating systems in developing countries are highlighted.     

Ecosystem Characteristics and Management Considerations for Coastal Wetlands in Mexico

Ecological parameters characterizing physico-chemical and biological conditions were collected from a total of 29 representative wetlands that occur between the near-shore terrestrial ecosystems and the outer edge of the tidal zone along the coasts of Mexico. This total includes about 40% of the total extent of coastal wetlands in Mexico. It is possible to recognize four distinct groups of wetlands based largely on the salinity gradients: oligohaline (0–10 ppt), estuarine (10–30 ppt), euhaline (30–40 ppt), and hyperhaline (>40 ppt). Estuarine wetlands are the most abundant and widespread group. Oligohaline wetlands are more common in the south and the hyperhaline wetlands are more common along the north coasts of Mexico. Euhaline systems are in specialized localities scattered along both coasts. Human activities and development pressures continue to threaten the coastal wetlands in Mexico. This paper presents the first survey of ecological characteristics of the coastal wetlands in Mexico. These data highlight the range of variability that exists, demonstrates problems such as eutrophication, and provides a basis for future more detailed biomonitoring, management and conservation programs for these highly vulnerable and economically important ecosystems in Mexico.     

Postglacial history of New Zealand wetlands and implications for their conservation

Most New Zealand wetlands formed at or after the end of the last glaciation (c.?18?000 cal yrs BP). Those associated with major rivers and close to the coast tend to be young as erosive processes both destroy and initiate wetlands. However, there is a strong linear trend in initiations since 14?000 cal yrs BP, which suggests that geomorphic processes such as soil deterioration, landslides, sand dune movement and river course changes are constantly adding new, permanent wetlands. Most wetlands began as herbaceous fens but usually transitioned to shrub- or forest-covered bog?fen systems, in particular after the beginning of the Holocene (11?500 cal yrs BP). Raised bogs formed from fens during the late-glacial and early Holocene, when river down-cutting isolated them from groundwater inflow. As climates warmed through the late-glacial and early Holocene, wooded wetlands spread and over 75% of lowland peat profiles preserve wood layers. Large basins with high water inflow often contain lakes or lagoons and have maintained herbaceous swamps, whereas those with limited catchments have become almost entirely covered with forest or shrub. Wetlands in drier districts tend to have been initiated during the mid- and late Holocene as the climate cooled and rain-bearing systems penetrated more often. Ombrogenous montane and alpine bogs may have been initiated by the same climate change. Natural fires frequently burnt some wetlands, particularly within the vast bog complexes of the Waikato Basin, but many wetlands record occasional fire episodes. By the time M?ori arrived in the 13th century, about 1% of the landscape was covered with some form of wetland and most of that wetland was under woody cover. M?ori firing of the landscape began the process of removing the woody cover, which induced wetter, more herbaceous systems and initiated new wetlands. Deforestation of catchments in drier districts increased water yield that may in turn have created lowland fens and lagoons. European logging, fire and draining destroyed both pristine forested wetlands and fire-transformed systems from the M?ori settlement era. The loss of wetlands is now largely a crisis of continued degradation through draining, weed invasion and fire in already human-altered systems in productive landscapes. Wetland history can help assess values and inform goals for conservation of wetlands, but transformation of the lowland landscape has been so complete that an historically authentic endpoint is unrealistic for most wetlands. The major conservation emphasis should be on larger wetlands that provide a range of ecosystem services.     

A synthesis of past,current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa

Papyrus wetlands (dominated by the giant sedge Cyperus papyrus L.) occur throughout eastern, central and southern Africa and are important for biodiversity, for water quality and quantity regulation and for the livelihoods of millions of people. To draw attention to the importance of papyrus wetlands, a special session entitled “The ecology of livelihoods in papyrus wetlands” was organized at the 9th INTECOL Wetlands Conference in Orlando, Florida in June 2012. Papers from the session, combined with additional contributions, were collected in a special issue of Wetlands Ecology and Management. The current paper reviews ecological and hydrological characteristics of papyrus wetlands, summarizes their ecosystem services and sustainable use, provides an overview of papyrus research to date, and looks at policy development for papyrus wetlands. Based on this review, the paper provides a synthesis of research and policy priorities for papyrus wetlands and introduces the contributions in the special issue. Main conclusions are that (1) there is a need for better estimates of the area covered by papyrus wetlands. Limited evidence suggests that the loss of papyrus wetlands is rapid in some areas; (2) there is a need for a better understanding and modelling of the regulating services of papyrus wetlands to support trade-off analysis and improve economic valuation; (3) research on papyrus wetlands should include assessment of all ecosystem services (provisioning, regulating, habitat, cultural) so that trade-offs can be determined as the basis for sustainable management strategies (‘wise use’); (4) more research on the governance, institutional and socio-economic aspects of papyrus wetlands is needed to assist African governments in dealing with the challenges of conserving wetlands in the face of growing food security needs and climate change. The papers in the special issue address a number of these issues.     

Prioritising wetlands subject to secondary salinisation for ongoing management using aquatic invertebrate assemblages: a case study from the Wheatbelt Region of Western Australia

Secondary salinisation is recognised worldwide as a threat to aquatic biodiversity. Wetlands in the Wheatbelt Region of Western Australia are particularly affected as a result of clearing of deep-rooted native vegetation for agriculture. Between 1996 and 2001, the Western Australian government nominated six natural diversity recovery catchments (NDRCs), being catchments with high value and diverse wetlands in need of protection. One, the Buntine–Marchagee NDRC, supports approximately 1000 wetlands in varying states of salinisation. The challenge is to prioritise these wetlands for ongoing management. In this paper we propose an approach to prioritise representative wetlands using aquatic invertebrates. On the basis of hydrology, salinity and remnant vegetation, 20 wetlands covering a range of salinities were selected for sampling of water quality and aquatic invertebrates. Of the 202 taxa recorded, most endemic taxa occurred in fresh/brackish wetlands, while hypersaline wetlands supported predominantly cosmopolitan species. Taxa richness was greater in fresh/brackish than saline and hypersaline wetlands, with conductivity explaining 83 % of between-wetland variation in taxa richness. Classification using invertebrate assemblages separated fresh/brackish, saline and hypersaline wetlands, with greatest between-year variability within saline and hypersaline sites. Wetlands were ranked using taxa diversity, presence of conservation-significant taxa and temporal similarity. Mean rank across indices provided the final overall order of priority. Hypersaline wetlands were ordered separately to the fresher water wetlands (fresh/brackish and saline) so that priority for future management was detailed for both types of wetlands. The analysis indicated that although fresh/brackish sites support the highest biodiversity, naturally saline sites also supported wetland assemblages worthy of ongoing protection.     

Vegetation communities in continental boreal wetlands along a salinity gradient: Implications for oil sands mining reclamation

Oil sands mining is a major disturbance to boreal landscapes in north-eastern Alberta, Canada. Freshwater peatlands dominate the landscape prior to mining, but the post-mining reclamation landscape will have wetlands that span a salinity gradient. Little is known about the native vegetation communities in subsaline and saline marshes in the boreal region, yet these communities offer the best potential for reclamation of wetlands after oil sands mining. The overall intent of this study is to provide information on natural wetland communities along a gradient of salinities that can be used to enhance oil sands wetland reclamation. Our specific study objectives were to: (1) characterize environmental conditions of industrial and natural wetlands, (2) characterize vegetation communities (composition and diversity) in these wetlands, (3) and explore how vegetation communities (composition and diversity) may be influenced by environmental conditions. We surveyed vegetation communities and environmental variables in 25 natural boreal wetlands along a salinity gradient and in 10 industrial marshes in the oil sands mining region. We observed an electrical conductivity (EC) range of 0.5-28 mS cm⁻¹ in the wetlands, indicating that salinity similar to or higher than anticipated for oil sands reclamation is naturally present in some boreal wetlands. We observed low species richness in both industrial and natural wetlands. There were 101 plant species observed in all the wetlands, with 82 species recorded in the natural wetlands and 44 species in industrial wetlands. At the plot level, richness decreased with increasing EC and pH, but increased with soil organic matter. Using Cluster Analysis and indicator species analysis we defined 16 distinct vegetation community types, each dominated by one or two species of graminoid vegetation. In general these communities resembled those of boreal or prairie marshes. Electrical conductivity, pH, and water depth were important factors correlating with community composition of the wetlands, however peat depth and soil organic content did not differ among community types. Not all community types were present in industrial wetlands, indicating that these communities may need to be planted to enhance overall diversity in future reclaimed oil sands wetlands.     

Reasons for the loss and degradation of Australian wetlands

Wetland conservation and management in Australia is not supported by a comprehensive information base. A national inventory has not been compiled and we have very little information on the areal extent and loss of wetlands. Further, we have little information on the values and benefits (products, functions and attributes) derived from wetlands and how these have been degraded or lost. We do know, however, that in some areas at least, wetland loss and degradation has been severe and may even be still occurring. Much of the scientific attention to wetland management has been directed towards the apparent (or ecological) reasons for wetland loss and degradation – changes to the water regime, physical modification of the habitat, eutrophication and other pollution, and invasion by exotic pest species. Lists of threats to wetlands have been compiled, but these rarely address the non-ecological reasons that have resulted in so many wetlands being lost or degraded. In this paper we summarize the key points made from a number of case studies of Australian wetlands that highlight the non-ecological causes of wetland loss and degradation. From this analysis we conclude that awareness and understanding about the non-ecological causes of wetland loss and degradation need to be as well understood as the ecological causes. Foremost amongst these we highlight greater attention to the following issues: economic development in wetlands, bureaucratic obstacles, lack of information or poor access to information, and poor general awareness of the values and benefits derived from wetlands. We further conclude that wetland loss and degradation does not need to happen – our wetlands are valuable and already severely degraded. For this situation to be rectified we need to ensure that the knowledge and expertise of wetland scientists is heard and heeded by decision-makers and wetland users and owners.     

Designing constructed wetlands for reclamation of pretreated wastewater and stormwater

Wastewater reclamation is getting greater attention as an alternative to conventional approaches to wastewater treatment and water supply due to increasing water stress coupled with more stringent water quality limitation for discharge of treated wastewater. Among the few technologies adopted in the field for wastewater reclamation, constructed wetlands have been used to reclaim both primary and secondary treated wastewater in regions with arid and humid climates. This paper summarizes the widely adopted guidelines that need to be considered when designing constructed wetlands for wastewater reclamation, discusses the capacity of wetland treatment systems for water reuse while assessing the status of full-scale constructed wetlands designed for wastewater reclamation, and develops contaminant loading charts as a design tool based on the performance of existing full-scale constructed wetlands deployed for wastewater reclamation. It is evident that constructed wetland systems provide a viable means to treat wastewater to the levels required for low-quality reuses such as restricted irrigation and impoundment. It is challenging for constructed wetlands to consistently meet microbiological guidelines for high-quality reuses such as unrestricted agricultural and urban reuses. Wastewater reclaimed through constructed wetlands is used mainly for agricultural and landscape irrigation, groundwater recharge, indirect potable reuse, and environmental reuse. Surface area and hydraulic loading rate of constructed wetlands to be deployed for wastewater reclamation can be estimated with contaminant loading charts derived from monitoring data of existing full-scale operations.     

Indicators for contaminant transport in wetlands

Wetlands provide significant ecological services for urban regions in terms of water supply, wastewater treatment, flood storage, drought resistance, etc. For wetland flows, it is crucial to understand the process of contaminant transport as it provides scientific support for applications associated with various urban services. Two indicators respectively as the critical length and duration are frequently adopted for risk assessment of incidental release of toxic or contaminant cloud. This paper presents a review on recent progresses in the analytical study of contaminant transport in wetland flows by Taylor dispersion at the phase-average scale. The method of concentration moments is introduced. Analytical procedures for determining the key quantity of Taylor dispersivity are given for typical wetlands with free water surface, respectively as the steady flow wetlands, tidal flow wetlands, and the two-layer flow wetlands. As an example of applications, critical length and duration of the contaminant cloud in the steady flow wetlands are analyzed based on the obtained Taylor dispersivity. Results show that in contrast to the temporary, localized influence of COD on water quality, the heavy metal Pb can give rise to more severe damage.     

The application of a framework for assessing ecological condition and sustainability of use to three wetlands in Malawi

In Africa, the direct use of wetlands has long contributed to livelihoods, but use may lead to the degradation of wetlands. In order to better understand how the biophysical features of a wetland influence the sustainability of its use, an investigation was undertaken of the ecological condition and use of three wetlands in the Kasungu District, Malawi, where human pressures on wetlands are high. The first wetland, at the head of the catchment, had sandy soils and a gentle longitudinal slope, the second wetland, lower in the catchment, had clay soils and a steeper longitudinal slope, and the third wetland was intermediate. A framework was applied to score five functional components of ecological condition: hydrology, geomorphology, soil organic matter (SOM) accumulation, nutrient cycling and vegetation composition in terms of human impact, based on pre-defined field indicators. The framework highlighted particular vulnerabilities of individual wetlands in the face of human pressure. Vulnerability varied greatly across the wetlands in terms of: recovery of native vegetation composition following cultivation, geomorphic change through gully erosion and depletion of SOM. The framework is recommended for wider application in Africa as a means of highlighting the specific vulnerabilities of individual wetlands and for the improved focus of organizations which promote the ecologically sustainable use of wetlands.     

Assessing the potential for biotic communities to recolonise freshwater wetlands affected by sulfidic sediments

1. The formation of sulfidic sediments in response to factors such as secondary salinisation and fertiliser usage is an emerging concern for the management of many freshwater wetlands. However, fundamental knowledge regarding the influence of sulfidic sediments on the aquatic biota is still lacking. 2. This study investigated the potential for biota to recolonise wetlands affected by sulfidic sediments, by assessing zooplankton hatching and aquatic plant germination following inundation with freshwater. Sediment samples were collected from 16 wetlands in the southern Murray‐Darling Basin, Australia, that ranged in condition from non‐impacted to possessing a known history of sulfidic sediments and/or acidification. 3. Principal Components Analysis indicated that the wetlands separated out into five different groups based on their sediment chemistry: non‐impacted, sulfidic, sulfidic and highly saline (sediment EC 46 800–209 000 μS cm^?1), sulfidic and potentially acidic (sediment pH 5.81–6.45 and ANC 0.07–0.31% CaCO₃), and sulfidic and acidic (sediment pH 4.37 and ANC 0.00% CaCO₃). 4. A viable dormant propagule bank was present in all wetlands, but the taxon richness of zooplankton and aquatic plants was significantly lower in wetlands affected by sulfidic sediments compared with those that were non‐affected. 5. This suggests that zooplankton and aquatic plants will be capable of recolonising wetlands that have accumulated sulfidic sediments via their propagule banks if the appropriate remediation measures are undertaken, although the communities developing are likely to be less diverse compared with those in non‐affected wetlands.     

Compensating for wetland losses in the United States

Impacts of climate change on US wetlands will add to those of historical impacts due to other causes. In the US, wetland losses and degradation result from drainage for agriculture, filling for urbanization and road construction. States that rely heavily on agriculture (California, Iowa, Illinois, Missouri, Ohio, Indiana) have lost over 80% of their historical area of wetlands, and large cities, such as Los Angeles and New York City, have retained only tiny remnants of wetlands, all of which are highly disturbed. The cumulative effects of historical and future degradation will be difficult to abate. A recent review of mitigation efforts in the US shows a net loss of wetland area and function, even though 'no net loss' is the national policy and compensatory measures are mandatory. US policy does not include mitigation of losses due to climate change. Extrapolating from the regulatory experience, one can expect additional losses in wetland areas and in highly valued functions. Coastal wetlands will be hardest hit due to sea-level rise. As wetlands are increasingly inundated, both quantity and quality will decline. Recognition of historical, current and future losses of wetland invokes the precautionary principal: avoid all deliberate loss of coastal wetland area in order to reduce overall net loss. Failing that, our ability to restore and sustain wetlands must be improved substantially.     

Tropical wetlands for climate change research, water quality management and conservation education on a university campus in Costa Rica

EARTH University is a small agronomic university with a theme of sustainability in eastern Costa Rica. Several natural and constructed wetlands on its campus are used for research, water quality improvement, and higher education. It has become an important location for research and teaching on humid tropical wetland ecology and management. A 112-ha flow-through Raphia taedigera (Arecaceae) forested wetland is being used for climate change research, focusing on carbon sequestration and methane generation. Methane emissions are measured seasonally and are comparable to rates in tropical wetlands published elsewhere. Carbon sequestration by the wetland appears to be substantially higher than similar flow-through temperate zone wetlands. Treatment wetlands are used on campus to improve water quality of effluents from an animal farm, a dairy plant, a landfill, and a banana paper plant. Water quality was substantially improved in all of these wetlands except the landfill leachate wetland. All of these campus wetlands have been integrated into the four-year education program of EARTH University and 22 undergraduate projects have been completed on wetlands over the past 14 years.     

Patterns and drivers for wetland connections in the Prairie Pothole Region,United States

Ecosystem function in rivers, lakes and coastal waters depends on the functioning of upstream aquatic ecosystems, necessitating an improved understanding of watershed-scale interactions including variable surface-water flows between wetlands and streams. As surface water in the Prairie Pothole Region expands in wet years, surface-water connections occur between many depressional wetlands and streams. Minimal research has explored the spatial patterns and drivers for the abundance of these connections, despite their potential to inform resource management and regulatory programs including the U.S. Clean Water Act. In this study, wetlands were identified that did not intersect the stream network, but were shown with Landsat images (1990–2011) to become merged with the stream network as surface water expanded. Wetlands were found to spill into or consolidate with other wetlands within both small (2–10 wetlands) and large (>100 wetlands) wetland clusters, eventually intersecting a stream channel, most often via a riparian wetland. These surface-water connections occurred over a wide range of wetland distances from streams (averaging 90–1400 m in different ecoregions). Differences in the spatial abundance of wetlands that show a variable surface-water connection to a stream were best explained by smaller wetland-to-wetland distances, greater wetland abundance, and maximum surface-water extent. This analysis demonstrated that wetland arrangement and surface water expansion are important mechanisms for depressional wetlands to connect to streams and provides a first step to understanding the frequency and abundance of these surface-water connections across the Prairie Pothole Region.     

Frog breeding in rain-fed wetlands after a period of severe drought: implications for predicting the impacts of climate change

Globally, rain-fed wetlands provide critical habitat for a wide range of amphibian species, however, information on the use of rain-fed wetlands by Australian frog species is extremely limited. This study examined the distribution of frog breeding in rain-fed wetlands following the first significant rain event after a period of severe drought (2002–2009) in order to predict how frog communities may be affected in the future by changed climate. Tadpole communities along with vegetation and water quality variables were described in 35 rain-fed wetlands across the South West Slopes and Riverina bioregions of inland south-eastern Australia. In addition, weekly tadpole surveys were conducted in a subset of these wetlands to describe temporal patterns of occupancy. Despite the protracted dry period prior to this study 50% of the rain-fed wetlands surveyed contained tadpoles. However, frog communities were species poor with only five species recorded. The majority of wetlands were dominated be a single species, Limnodynastes tasmaniensis which is also common within permanent waterbodies such as farm dams and irrigation infrastructure in both bioregions. Tadpoles of two burrowing species L. interioris and Neobatrachus sudelli were restricted to a small number of wetlands mostly in the South West Slopes. The composition of tadpole communities changed over time, and Crinia parinsignifera was the only species that continued to breed over winter. The dominance of generalist species within rain-fed wetlands indicates that characteristics such as dispersal capability, flexibility in breeding times and the ability to utilise created habitats may be more important than burrowing ability and longevity when predicting vulnerability to climate change.     

Metal species indicate the potential of constructed wetlands for long-term treatment of metal mine drainage

Experimental peat-based wetlands at the former Bell Copper Mine (Smithers, B.C., Canada) removed copper from low strength (0.3–1.0 ppm, pH 6–8) and high strength (35–50 ppm, pH 3) copper-contaminated mine drainage. Copper species retained in wetlands sediments were quantified as a means to assess the long-term potential of these wetlands for treating mine drainage. Previous microbial and chemical analyses had indicated that sulphide was biologically generated in these wetlands, and mineralogical analysis confirmed that copper sulphides were present in wetland sediments. However, sequential leaching of these sediments showed that copper was predominantly in organically-bound and oxide-bound phases, with a smaller proportion present as sulphides. The available data suggest that much of the copper was retained as sulphides when low strength mine drainage was applied to the wetlands.     

Adaptation of wastewater surface flow wetland formulae for application in constructed stormwater wetlands

Over the past 30 years, the use of constructed wetlands for wastewater treatment has been a topic of significant research culminating in a good data base from which simplistic equations have been derived to aid in the design of these facilities to meet long term water quality treatment performance criteria. Over the past decade, the use of treatment wetlands has extended to stormwater and combined sewer overflow (CSO) management applications. Designing constructed wetlands for stormwater and CSO applications have unique challenges stemming from the highly stochastic nature of the hydraulic and pollutant loading on a stormwater wetland compared with wastewater treatment systems. This paper explores the possibility of adapting the simplistic models for wastewater wetlands for interim use in developing design guidelines for stormwater wetland systems. A procedure that takes into account the unsteady intermittent nature of stormwater inflows to these wetlands has been incorporated into one of these simplistic models and a case study presented to demonstrate the application of the procedure.     

Effect of time on consistent and repeatable macrophyte index for wetland condition

The vegetation portion of the Florida Wetland Condition Index (FWCI), an index of biological integrity, provided consistent and repeatable measures of condition at eighteen wetlands sampled in two consecutive growing seasons. The sample wetlands reflected a gradient of adjacent land use from non-impacted reference areas to wetlands imbedded within silviculture, cattle pasture and residential areas. Wetlands were described as herbaceous depression (n = 6), forested depression (n = 5) and forested strand or floodplain wetlands (n = 7), and represented different states of succession. Even though the wetlands were unique from one another and occurred across a large geographic area in Florida, the FWCI results calculated for all the wetlands were representative of adjacent land use impacts and not sensitive to natural variation. During the duration of this study, changes in weather from drought to tropical storm conditions, as well as management activities such as fire and herbivory, impacted wetlands. These effects were apparent in the change of species composition between sampling periods; 23–56% of species were different when resampled. Even though composition changed, the proportion of indicators remained consistent. The resulting condition scores suggested a one-to-one relationship between sampling periods.