Wetland Restoration Projects Research Articles

Controlling Phalaris arundinacea (reed canarygrass) with live willow stakes: A density-dependent response

We tested the use of live willow stakes to manage reed canarygrass ( Phalaris arundinacea L.) invasions on a wetland site. We planted willow at densities of 0.60 m (2 ft) centers, 0.91 m (3 ft) centers, 1.21 m (4 ft) centers, and control (no plantings) on a sloping wetland edge at Lake Washington, Seattle, U.S.A., where reed canarygrass dominated prior to the experiment. Soil moisture content was measured along the slope gradient, resulting in three soil moisture classes per replicate. Willow leaf area index and reed canarygrass aboveground biomass were measured after each of two consecutive growing seasons and analyzed using ANCOVA. Relative to the controls, the willows reduced total biomass of reed canarygrass by 44.9% with 0.60 m spacing in the first year and by 68.0% with 0.60 m spacing and 56.1% with 0.91 m spacing in the second year. Differences in soil moisture did not affect reed canarygrass aboveground biomass or effects of willow on reed canarygrass, but did affect willow growth, perhaps through reed canarygrass competition under lower soil moisture conditions. We recommend the 0.60 and 0.91 m spacings for wetland restoration projects attempting to manage reed canarygrass through live willow staking.

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5– 18 g l−1) to hyperhaline (>40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

Clonal variation in response to salinity and flooding stress in four marsh macrophytes of the northern gulf of Mexico, USA

Intraspecific variation in stress tolerance can be an important factor influencing plant population structure in coastal wetland habitats. We studied clones of four species of emergent marsh macrophytes native to the northern coast of the Gulf of Mexico in Louisiana, USA, to examine variation in response to salinity and flooding stress under controlled greenhouse conditions. Clones of Distichlis spicata, Phragmites australis, Schoenoplectus californicus, and Schoenoplectus robustus were collected across the coastal zone of Louisiana. After vegetative propagation through at least three generations to remove acclimation to field conditions, four to six clones of each species were selected for use in the experiment. Treatments consisted of three salinity levels and two water depths, and species were assigned to either a brackish marsh ( P. australis, S. californicus) or salt marsh ( D. spicata, S. robustus) group for treatment application. Treatment effects on plant growth (stem number, total height, and mean height, and aboveground and belowground biomass) were examined, and physicochemical characteristics within treatments (redox potential, and interstitial water pH, salinity, temperature, and nutrients) were monitored. Clonal variation in growth was indicated in all species, and was more pronounced in D. spicata and P. australis than in S. californicus and S. robustus. Distichlis spicata and P. australis clones were assigned to relative categories of low, intermediate, and high tolerance to the imposed stressors. Similar generalizations on clonal stress tolerance were not possible for the two Schoenoplectus species. Overall species response to imposed stressors was also identified through non-statistical comparisons. Phragmites australis was more tolerant than S. californicus of increased salinity. Distichlis spicata was more tolerant of increased salinity but less tolerant of increased water depth than was S. robustus. Our results suggest that information on species and clone variations in growth and tolerance to salinity and flooding stressors can be used to select a variety of plant materials suitable for wetland restoration projects.

Hydrologic Regime Controls Soil Phosphorus Fluxes in Restoration and Undisturbed Wetlands

Abstract Many wetland restoration projects occur on former agricultural soils that have a history of disturbance and fertilization, making them prone to phosphorus (P) release upon flooding. To study the relationship between P release and hydrologic regime, we collected soil cores from three restoration wetlands and three undisturbed wetlands around Upper Klamath Lake in southern Oregon, U.S.A. Soil cores were subjected to one of three hydrologic regimes—flooded, moist, and dry—for 7.5 weeks, and P fluxes were measured upon reflooding. Soils from restoration wetlands released P upon reflooding regardless of the hydrologic regime, with the greatest releases coming from soils that had been flooded or dried. Undisturbed wetland soils released P only after drying. Patterns in P release can be explained by a combination of physical and biological processes, including the release of iron‐bound P due to anoxia in the flooded treatment and the mineralization of organic P under aerobic conditions in the dry treatment. Higher rates of soil P release from restoration wetland soils, particularly under flooded conditions, were associated with higher total P concentrations compared with undisturbed wetland soils. We conclude that maintaining moist soil is the means to minimize P release from recently flooded wetland soils. Alternatively, prolonged flooding provides a means of liberating excess labile P from former agricultural soils while minimizing continued organic P mineralization and soil subsidence.

From Wasteland to Wetland

From Wasteland to Wetland

Applying science to conservation and restoration of the world's wetlands

The world has an estimated 7 to 9 million km2 of wetlands which can be defined through their hydrology, physiochemical environment, and biota. Many human cultures have lived in harmony with wetland environments for centuries. Many others have not, resulting in drainage or severe impact of wetlands throughout the world. Conservation of wetlands needs to be a priority for the cultural and ecological values they provide. But a more optimistic note is that large-scale restoration and re-creation of wetlands and riverine systems is beginning to happen throughout the world through ecological engineering. Examples of large-scale wetland restoration projects are presented for Delaware Bay, the Skjern River (Denmark), Florida Everglades, Louisiana Delta, the Mississippi River Basin, and the Mesopotamian Marshlands of Iraq.

Nature-based Leisure and Tourism in England’s Humberhead Levels

An evaluation of nature-based leisure and tourism as drivers for change in the Humberhead Levels is part of ongoing research with the Countryside Agency (CoAg). The Agency wishes to facilitate objectives of the Value in Wetness (Land Management Initiative) to re-establish wetlands and wetter landscapes across much of the area. To achieve a more sustainable wetland landscape with a vibrant farming and rural economy it is necessary to identify barriers and triggers for change. Diversification into nature-based leisure and tourism in the context of sustainable tourism, focusing on water- and wetland-related initiatives could be a way forward. This paper reports a scoping study and audit of outdoor leisure and tourism assets. It follows reviews of the Outdoor Leisure Industry (Beard et al., 2000) and the Wildlife Leisure Industry (Rotherham et al., 2000). These developed the importance of Wildlife Leisure as a concept in sustainable tourism and rural development. The Humberhead Levels research moves this from concept to near implementation. Relevant tourism information was collated to help establish the importance of the sector to a geographic area such as the Humberhead Levels. The reasons for current failings are noted. Case studies of selected wetland creation and restoration projects are presented and discussed. The research indicates significant contributions of nature-based leisure and tourism to regional and local economies. It also highlights problems of awareness, coordination and absence of the necessary support infrastructures at all levels. The importance of attracting new visitors and retaining local users is discussed.

Restoring natural seepage conditions on former agricultural grasslands does not lead to reduction of organic matter decomposition and soil nutrient dynamics

In the central part of the Netherlands, wetland restoration projects involve the rewetting of former agricultural land, where low water levels were artificially maintained (polders). Many of these projects do not result in the expected reduction of nitrogen and phosphorus availability and subsequent re-establishment of a diverse wetland vegetation. The aim of the present study was to investigate which mechanisms are responsible for this lack of success. Thereto, we studied the effect of rewetting of former agricultural grasslands on acidified peat soil (pH = 3.5) on organic matter decomposition, nitrogen cycling and phosphorus availability in the soil for three seasons. To provide an explanation for the observed effects, we simultaneously studied a set of potentially controlling abiotic soil conditions that were expected to change after rewetting. It was found that rewetting of these grasslands with natural, unpolluted seepage water did not affect nitrogen cycling, but raised decomposition rates and almost doubled phosphorus availability. The main cause of these effects is a raise of soil pH to about 7 due to the hydrochemical composition of the soil pore water after rewetting, which reflects groundwater with high amounts of buffering ions. This effect overruled any reduction in process rates by the lowered soil redox potential. The counterintuitive finding of eutrophication after rewetting with natural and unpolluted water is considered to represent a new form of internal eutrophication, triggered by the restoration of natural site conditions of former agricultural land on acid peat soil.

Restoring complex vegetation in urban settings: The case of tidal freshwater marshes

Tidal freshwater marshes have diverse plant communities that vary spatially and temporally due to hydrology, animal activity, and other factors. Development of urban centers along rivers of the U.S. Atlantic coast has reduced the historic extent and quality of these and other coastal wetlands. Because the vegetation of these wetlands is more complex than that of salt and brackish marshes (where restoration of vegetation typical of natural systems has sometimes been successful), restoration of tidal freshwater marsh vegetation is likely to be more difficult, particularly in urban areas. Watershed urbanization alters hydrology, sediment load, propagule availability and composition, nutrient status, and other variables that together create an environment different from that of wetlands in less developed areas, possibly precluding restoration of typical marsh vegetation. Tidal freshwater wetlands were historically extensive along the Anacostia River in Washington, DC, but most of these were lost due to filling, dredging, or hydrologic alteration. Over the last decade, the U.S. Army Corps of Engineers has implemented projects designed to restore tidal freshwater wetlands along the Anacostia, which involved increasing elevation with dredged river sediment and planting native vegetation. To illustrate some of the mechanisms affecting vegetation development in restored tidal freshwater marshes in urban areas, I present a case study on one of these wetlands, Kingman Marsh, that also includes research at another restored wetland and two natural reference sites. Studies by my research groups indicate that the restored wetlands undergo essentially a planting-modified process of primary succession. Low densities of seeds are initially present in the substrate, and prolific seed dispersal into the restored sites results in high initial plant diversity comprised of plantings and ruderal (i.e. weedy) natives and exotics. Seed banks develop rapidly at the restored sites, probably due to colonization and early reproduction by ruderal species. Hydrology and disturbance by non-native animals (including resident Canada goose) are important variables controlling establishment of vegetation in these systems. Recent literature and the case study indicate that the environmental conditions of urban settings impose constraints in restored wetlands that result in plant communities more like those of urban natural wetlands than those of wetlands in less urbanized watersheds. This suggests that rather than design wetland restoration projects with the goal of creating “pristine” wetland vegetation, restorationists must identify, accept, and if possible capitalize on the ecological constraints of the urban environment in setting achievable and desirable restoration goals.

Effects of drought on the water-table dynamics of a southern Appalachian mountain floodplain and associated fen

Annual and seasonal variations in precipitation have been shown to influence the hydrology of nontidal wetlands, including depth to water table. Water-table depth is assessed in wetlands for a variety of reasons, most notably for wetland delineations or determining the success of restoration projects. Many short-term assessment efforts probably occur during periods of abnormal precipitation and, as such, may not provide a thorough understanding of wetland hydrology. I have been evaluating water-table dynamics of a wetlands complex in western North Carolina for seven years in support of a wetlands restoration project. A series of water-table wells and piezometers were installed to determine the spatial and temporal patterns of the water table and vertical hydraulic gradient (VHG). For over three years, the area was classified as having conditions of moderate to severe drought. The drought lowered the average monthly water table by 26 cm in a mountain fen and 22 cm in the adjacent floodplain. The fen was a constant ground-water recharge area before the drought and a discharge area for three of 12 months during the drought. The drought also impacted a shallow, constant ground-water source to the fen on an adjacent hillslope. The impacts of the drought were greater during the active growing season, presumably due to increased evapotranspiration. The results support the need for long-term hydrologic assessment of wetlands and the need to relate wetland hydrology to annual, seasonal, and monthly precipitation patterns.

A Comparison of Remote Sensing and Ground‐Based Methods for Monitoring Wetland Restoration Success

Abstract Efficient and accurate vegetation sampling techniques are essential for the assessment of wetland restoration success. Remotely acquired data, used extensively in many locations, have not been widely used to monitor restored wetlands. We compared three different vegetation sampling techniques to determine the accuracy associated with each method when used to determine species composition and cover in restored Pacific coast wetlands dominated by Salicornia virginica (perennial pickleweed). Two ground‐based techniques, using quadrat and line intercept sampling, and a remote sensing technique, using low altitude, high resolution, color and color infrared photographs, were applied to estimate cover in three small restoration sites. The remote technique provided an accurate and efficient means of sampling vegetation cover, but individual species could not be identified, precluding estimates of species density and distribution. Aerial photography was determined to be an effective tool for vegetation monitoring of simple (i.e., single‐species) habitat types or when species identities are not important (e.g., when vegetation is developing on a new restoration site). The efficiency associated with these vegetation sampling techniques was dependent on the scale of the assessment, with aerial photography more efficient than ground‐based sampling methods for assessing large areas. However, the inability of aerial photography to identify individual species, especially mixed‐species stands common in southern California salt marshes, limits its usefulness for monitoring restoration success. A combination of aerial photography and ground‐based methods may be the most effective means of monitoring the success of large wetland restoration projects.

Episodic colonization of an intertidal mudflat by native cordgrass (Spartina foliosa) at Tijuana Estuary

Following heavy winter storms and sedimentation in 1993,Spartina foliosa (Pacific cordgrass) clones established on a 6.5-ha mudflat in Tijuana Estuary, with over 80 new clones counted by 1997. El Nino Southern Oscillation (ENSO) storms in 1993 apparently facilitated the habitat conversion through river flooding, which caused a temporary reduction in soil salinity and delivered large volumes of sediment. Extreme sedimentation likely raised mudflat elevations enough to allowSpartina establishment. We hypothesized that clones, once established, increased sedimentation in a positive feedback loop leading to accelerated habitat conversion. We collected data on elevation,Spartina expansion, and sediment accretion in two consecutive years (1998–1999). The elevation range of the mudflats in 1998 (0.5–0.83 m NGVD) was within the elevation range ofSpartina at this site (0.39–0.83 m NGVD), indicating that remaining mudflats are at elevations suitable for further expansion. Sediment accretion ranged from 4.0–12.7 cm between 1997–1998 (ENSO conditions), but was close to long-term averages (˜ cm yr−1) in 1998–1999 (nonflood year) indicating how susceptible Tijuana Estuary is to sedimentation from episodic storms. Although accretion rates were similar withinSpartina clones and on bare mudflats over the ENSO winter, clones were typically dome-shaped suggesting higher sediment retention rates within clones. The radial expansion rates of clones (1.31±0.25 m in 1998; 1.12±0.07 m in 1999) approximated the maxima reported for this species and were not related to clone size or vigor. Conditions on the mudflat appear ideal forSpartina growth, masking differences that might otherwise be observed. Given the likelihood of sedimentation-driven habitat conversion in southern California and other Mediterranean-type estuaries, management efforts are needed to address sedimentation issues on a watershed scale. We recommend that wetland restoration projects in southern California include large areas of intertidal mudflat, both to maintain habitat for shorebird feeding and to allow colonization by salt marsh vegetation.

Variation in Size and Location of Wading Bird Colonies in the Upper St. Johns River Basin, Florida, USA

Abstract Wading bird nesting colonies were surveyed in the Upper St. Johns River Basin, east central Florida, USA in 1993-1995 and 1998-2000 using aerial survey methods. A total of 62 colony locations were found over six years, with a maximum of 35 sites active in each of two years. Borrow pits and managed impoundments were the most important nesting locations based on size and persistence. Most of these sites were in or adjacent to the Upper St. Johns River Basin Project, a wetland restoration project. Higher numbers of nests were counted during nesting seasons preceded by above average rainfall than during seasons characterized by drought. Cattle Egrets (Bubulcus ibis) were the most common nesting species in all years, however, the proportion of the total nests that were Cattle Egrets decreased over the study period. Wood Storks (Mycteria americana), a federally endangered species, nested in increasing numbers within three borrow pits adjacent to the Upper St. Johns River Basin Project. This study revea...

Changes in the macro-vegetation of the Kis-Balaton Wetlands over the last two centuries: a GIS perspective

The Kis-Balaton Water Protection System (KBWPS) is a wetland restoration project of over 8000 ha in extent, established to protect the water quality of Hungary's Lake Balaton. The healthy survival of the wetland macro-vegetation is essential for processes of bio-filtration, thus regular vegetation surveys have been carried out since the project began, to monitor the macrophyte growth in correspondence with the re-flooding. This biomonitoring is now very sophisticated, using ortho-photographs and a GIS database. However, the processes of wetland survival and regeneration are not fully understood, nor are the timescales involved; but there does exist in Hungary much archive cartography, especially since the 1780s, as well as records of the water-levels of Lake Balaton and of wetland extent and condition, which could be of great value in managing the KBWPS. Archive maps contain much information about past environments and if viewed in a historical series, can depict environmental change and response in some detail. In the first part of our study we used the maps of the KBWPS area produced by the three Military Surveys of Austria-Hungary (1783–84, 1856–57, 1872–74) to quantify the changes in vegetation cover over the last two centuries. In the second part of our study, we produced a Digital Elevation Model of the area and applied overlays representing the range of values of water-level in the archive data: thus we produced a series of maps showing the extent of water-cover and its depth for each level. We compared these to our derived vegetation maps for the same periods and were thus able to make assumptions on the vegetation-cover of the past and how it changed.

Application of the EPA Wetland Research Program approach to a floodplain wetland restoration assessment

Kolka, R.K., C.C. Trettin, E.A. Nelson, C.D. Barton, and D.E. Fletcher. 2002. Application of the EPA Wetland Research Program Approach to a floodplain wetland restoration assessment. J. Env. Monitoring & Restoration 1(1):37-51. Forested wetland restoration assessment is difficult because of the timeframe necessary for the development of a forest ecosystem. The development of a forested wetland ecosystem includes the recovery of hydrology, soils, vegetation, and faunal communities. To assess forested wetland restoration projects, measures need to be developed that are sensitive to early changes in community development and are predictive of future conditions. In this study we apply the EPS's Wetland Research Program's (WRP) approach to assess the recovery of two thermally altered riparian wetland systems in South Carolina. In one of the altered wetland systems, approximately 75% of the wetland was planted with bottomland tree seedlings in an effort to hasten recovery. Individual studies addressing hydrology, soils, vegetation, and faunal communities indicate variable recovery responses.

Hydraulic Geometry: A Geomorphic Design Tool for Tidal Marsh Channel Evolution in Wetland Restoration Projects

AbstractEmpirical hydraulic geometry relationships for tidal marsh channels are a practical geomorphically based design tool that can assist in the planning of tidal wetland restoration projects. This study provides hydraulic geometry relationships for predicting the depth, width, and cross‐sectional area of mature tidal channels as functions of contributing marsh area or tidal prism. The relationships are based on data from San Francisco Bay coastal salt marshes ranging in size from 2 to 5,700 ha. These hydraulic geometry relationships refine and expand on earlier relationships. Relationships for mature marshes can be used to predict the direction and rate of evolution of a channel in an immature or perturbed marsh system. Channel evolution data for three youthful tidal channels, ages 4 to 13 years, suggest that the channels are converging on their predicted equilibrium morphology. Two channels are eroding in response to significant increases in upstream tidal prism. They have enlarged first by deepening, in one case after 13 years to beyond the predicted equilibrium depth, and then widening through slumping of the channel banks. The third channel, a new one forming in a depositional mudflat, is converging on its equilibrium morphology after 13 years but will likely take several decades to equilibrate.

Spatial and temporal variation in estuarine fish and invertebrate assemblages: Analysis of an 11-year data set

Protocols for monitoring wetland mitigation and restoration projects call for routine counts of animals, yet long-term spatial and temporal patterns are rarely examined. An analysis of monitoring data from three southern California estuaries spanning 11 years, four seasons, and multiple stations within the estuaries revealed differences in spatio-temporal patterns between fish and invertebrates. Ordination analysis showed that fish assemblages were more predictable from environmental variables than were invertebrate assemblages. Variation in the fish assemblage was, primarily due to seasonal differences that were driven by changes in temperature. Invertebrates showed little seasonal variation, but a much higher degree of interannual variation than fish. Streamflow and dissolved oxygen were significant predictors of the invertebrate assemblage, indicating that irregular disturbances such as flooding events had a more important effect on the invertebrate assemblage than predictable seasonal cues such as temperature. Variation in fish and invertebrates was high both between and within the three estuaries, indicating that differences exist on multiple spatial scales. The influence of spatial and temporal factors on estuarine invertebrate and fish communities should be considered in planning monitoring programs for wetland mitigation or restoration sites.

Development of amplified fragment length polymorphism markers for Spartina alterniflora

Spartina alterniflora Loisel. plants have been transported across great distances for use in wetland restoration and creation projects. However, little information exists on the geographic genetic structure of S. alterniflora, such as the relatedness of populations within a region and the genetic similarity of imported populations to native populations. A high-resolution tool for assessing genetic similarity and diversity of S. alterniflora populations would be an important step toward understanding these relationships. We optimized a bead beater extraction and amplified fragment length polymorphism (AFLP) protocol for S. alterniflora and evaluated its usefulness in distinguishing plants from adjacent marshes in addition to marshes planted with imported stock. Two primer sets were used in AFLP analysis of four to five plants from each of seven populations. These primer sets generated 372 scoreable loci, of which 235 were polymorphic. High genetic diversity was observed in all populations studied, with nucleotide diversities ranging from 0.0363 to 0.0651. Results from analysis of molecular variance (AMOVA) in this exploratory analysis indicated that intrapopulation genetic diversity was high (59.8% of total variation). The contribution of regional differences was weak. Geographical distances between planting stock origin and native marshes did not correlate with genetic diversity. This study demonstrated the procedure could be used to rapidly and reproducibly generate high-resolution genetic profiles of individual plants. The data produced with this method will be used to further our understanding of the structure of S. alterniflora communities and their function in salt marshes.

TESTING THE FLORISTIC QUALITY ASSESSMENT INDEX AS AN INDICATOR OF WETLAND CONDITION

Biological indicators of ecosystem integrity are increasingly being sought for use in ecosystem assessment and goal-setting for restoration projects. We tested the effectiveness of a plant community-based bioassessment tool, the floristic quality assessment index (FQAI) in 20 depressional wetlands in Ohio, USA. A priori, the 20 depressional wetlands were classified by type and ranked to form a disturbance gradient according to the local landscape condition. Ranks were based on surrounding land cover characteristics, vegetated buffer characteristics, and the extent of human-induced hydrologic alteration at the wetland site. The index was negatively correlated with the disturbance rank of a wetland and with the distance to neighboring wetlands (P = 0.01). Index values were lower for wetlands surrounded by agricultural or urban land use, wetlands with less vegetation on the wetland perimeter, and wetlands with more hydrologic modification, and at sites with greater distances to other wetlands. The wetlands with lower FQAI values tended to be dominated by plants that are typical of heavily cultivated landscapes or urban regions. Thus, the index is interpreted as a measure of environmental factors that maintain and control plant communities. The index was not correlated with differences in wetland surface water chemistry (α = 0.05) but was positively correlated with soil total organic carbon (P = 0.01), phosphorus (P = 0.05), and calcium (P = 0.05). Repeated wetland sampling in the summer and autumn revealed that the floristic quality assessment index could be useful for the assessment and monitoring of wetland ecosystems and for tracking wetland restoration projects over time.

Anuran call surveys on small wetlands in Prince Edward Island, Canada restored by dredging of sediments

In 1990, the North American Waterfowl Management Plan (NAWMP) implemented a small-wetland restoration program in Prince Edward Island (PEI), Canada. Wetlands were restored by means of dredging accumulated sediment and organic debris to create open water and emulate pre-disturbance conditions. Three call surveys were conducted in the spring and summer of 1998 and 1999 to estimate abundance and occurrence of spring peepers (Pseudacris crucifer), wood frogs (Rana sylvatica), northern leopard frogs (Rana pipiens), American toads (Bufo americanus), and green frogs (Rana clamitans) on restored and reference wetlands. Numbers of species calling and abundance indices of northern leopard frogs green frogs and spring peepers were significantly higher on restored versus reference wetlands. The number of species calling in restored wetlands was positively correlated with proximity to freshwater rivers; in reference wetlands, the number was positively associated with forested perimeters and area of open water. Occurrence of calling green frogs in restored wetlands was positively correlated with percent cattail and, in reference wetlands, with proximity to other wetlands. Our results suggest that small wetland restoration projects may be a good conservation tool for anurans. We recommend further research on reproductive success and on local population trends in restored wetlands to determine if restoration is beneficial for anurans on PEI.