Vegetation,Invertebrate, and Wildlife Community Rankings and Habitat Analysis of Mitigation Wetlands in West Virginia

Numerous efforts have been made in West Virginia to construct and restore compensatory wetlands as mitigation for natural wetlands destroyed through highway development, timbering, mining, and other human activities. Because such little effort has been made to evaluate these wetlands, there is a need to evaluate the success of these systems. The objective of this study was to determine if mitigation wetlands in West Virginia were adequately supporting ecological communities relative to naturally occurring reference wetlands and to attribute specific characteristics in wetland habitat with trends in wildlife abundance across wetlands. Specifically, avian and anuran communities, as well as habitat quality for eight wetland-dependent wildlife species were evaluated. To supplement this evaluation, vegetation and invertebrate communities also were assessed. Wetland ranks were assigned based on several parameters including richness, abundance, diversity, density, and biomass, depending on which taxa was being analyzed. Mitigation wetlands consistently scored better ranks than reference wetlands across all communities analyzed. Canonical correspondence analysis revealed no correlations between environmental variables and community data. However, trends relating wetland habitat characteristics to community structure were observed. These data stress the need to maintain specific habitat characteristics in mitigated wetlands that are compatible with wildlife colonization and proliferation.     

Aquatic macroinvertebrate community responses to wetland mitigation in the Greater Yellowstone Ecosystem

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Litter decomposition in created and reference wetlands in West Virginia,USA

Large amounts of resources have gone into wetland mitigation in recent years; however, it is still unclear whether wetland function is being replaced along with wetland area. Litter decomposition is linked to numerous wetland functions. In this study, we measured plant litter decomposition potential over 12 months in 8 created and 8 reference wetlands located in the Allegheny Mountains of West Virginia, USA. Broadleaf cattail (Typha latifolia L.) litter bags were placed in each wetland and collected at 3 month intervals. Linear decomposition rate constants and percent mass remaining were similar between wetland types (created and reference) and among Cowardin classifications (palustrine: unconsolidated bottom, aquatic bed, emergent, and scrub/shrub). Created wetland age was not correlated with decomposition potential. Our study found that created wetlands had similar litter decomposition potential as reference wetlands indicating that similar processes are likely acting upon litter decomposition within both natural and created wetlands.     

Ecological function of constructed perennial stream channels on reclaimed surface coal mines

Mountaintop removal–valley fill mining results in the conversion of steep, forested headwater catchments to low gradient and open canopy channels. We compared the ecological functions of five reference stream channels to five constructed channels (age ranging from 3 to 20 years) on reclaimed mines in southern West Virginia. Variables included stream flow, habitat, water chemistry, riparian vegetation, organic matter (OM) processing, and invertebrate and amphibian communities. Although dissolved metal concentrations remained low, constructed channels produced significantly higher levels of conductivity and total dissolved solids as compared to reference streams. Macroinvertebrate and amphibian richness were comparable between constructed and reference channels; however, there was a distinct shift from sensitive lotic taxa in reference channels to tolerant lentic taxa in constructed channels. Constructed channels also had reduced OM decomposition rates. Nevertheless, constructed channels had significantly higher OM retention than reference channels, and consequently exhibited significantly higher overall OM processing and higher dissolved carbon concentrations. As the time since reclamation increased, we observed slight declines in conductivity and significant increases in total invertebrate richness. Our results provide measures of functional equivalencies between reference and constructed streams, which can serve as a basis for informed permitting and mitigation decisions in mined watersheds.     

A comparison of wetland characteristics between Agricultural Conservation Easement Program and public lands wetlands in West Virginia,USA

In West Virginia, USA, there are 24 conservation easement program wetlands enrolled in the Agricultural Conservation Easement Program (ACEP). These wetlands are located on private agricultural land and are passively managed. Due to their location within fragmented agricultural areas, wetlands enrolled in ACEP in West Virginia have the potential to add wetland ecosystem services in areas that are lacking these features. We evaluated ACEP wetlands compared to reference wetlands on public land in West Virginia by using surrounding land cover, vegetative cover, and wetland features and stressors such as the presence or absence of erosion, upland inclusion, algal mats, and evidence of impacts from the surrounding landscape as surrogate measurements of wetland function on 13 ACEP wetlands and 10 reference wetlands. ACEP wetlands had higher percentages of tree coverage and a higher proportion of agricultural land in the areas immediately surrounding the wetland. Reference wetlands had higher percent coverage of emergent vegetation and had a higher proportion of forest in the immediate landscape. Our findings suggest that ACEP wetlands provide valuable early successional and forested wetland cover in a state that is largely forested. Because of this, it is important to maintain and even expand ACEP in West Virginia to continue providing a valuable source of early successional wetland habitat.     

Effects of Local and Landscape Variables on Wetland Bird Habitat Use During Migration Through the Rainwater Basin

ABSTRACT Staging areas and migratory stopovers of wetland birds can function as geographic bottlenecks; common dependence among migratory wetland bird species on these sites has major implications for wetland conservation. Although 90% of playa wetlands in the Rainwater Basin (RWB) region of Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for up to 10 million waterfowl each spring. Our objectives were to determine local (within wetland and immediate watershed) and landscape-scale factors influencing wetland bird abundance and species richness during spring migration at RWB playas. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 1.6 million individual migratory wetland birds representing 72 species during spring migrations 2002–2004. We tested a priori hypotheses about whether local and landscape variables influenced overall species richness and abundance of geese, dabbling ducks, diving ducks, and shorebirds. Wetland area had a positive influence on goose abundance in all years, whereas percent emergent vegetation and hunting pressure had negative influences. Models predicting dabbling duck abundance differed among years; however, individual wetland area and area of semipermanent wetlands within 10 km of the study wetland consistently had a positive influence on dabbling duck abundance. Percent emergent vegetation also was a positive predictor of dabbling duck abundance in all years, indicating that wetlands with intermediate (50%) vegetation coverage have the greatest dabbling duck abundance. Shorebird abundance was positively influenced by wetland area and number of wetlands within 10 km and negatively influenced by water depth. Wetland area, water depth, and area of wetlands within 10 km were all equally important in models predicting overall species richness. Total species richness was positively influenced by wetland area and negatively influenced by water depth and area of semipermanent wetlands within 10 km. Avian species richness also was greatest in wetlands with intermediate vegetation coverage. Restoring playa hydrology should promote intermediate percent cover of emergent vegetation, which will increase use by dabbling ducks and shorebirds, and decrease snow goose (Chen caerulescens) use of these wetlands. We observed a reduction in dabbling duck abundance on wetlands open to spring snow goose hunting and recommend further investigation of the effects of this conservation order on nontarget species. Our results indicate that wildlife managers at migration stopover areas should conserve wetlands in complexes to meet the continuing and future habitat requirements of migratory birds, especially dabbling ducks, during spring migration.     

Variation in wetland invertebrate communities in lowland acidic fens and swamps

1. Invertebrates were collected semi‐quantitatively from four relatively undisturbed wetlands in the west coast of New Zealand’s South Island: two acidic fens and two swamps. Samples were collected from up to four discrete habitats within each wetland: large open‐water channels, small leads (small, ill‐defined channels with emergent vegetation in them) and large (>10 m diameter) or small (<10 m diameter) ponds. Samples were also collected from different plant species within each wetland, each with different morphology, and from areas without vegetation. This was done to determine whether invertebrate communities varied more between‐wetlands than within‐wetlands, as the results had implications for future wetland monitoring programmes. 2. Principal components analysis of water chemistry data revealed striking differences in pH, conductivity and nutrients between the four wetlands. Not surprisingly, pH was lowest in one of the acidic fens, and highest in one of the swamps, where conductivity was also high. Midges (Tanytarsus, Tanypodinae, Orthocladiinae and Ceratopogonidae), nematodes, harpactacoid copepods and the damselfly Xanthocnemis dominated the invertebrate fauna. Orthoclad midges and mites were the most widespread taxa, found in 91 of 94 samples. Diptera were the most diverse invertebrate group, followed by Trichoptera and Crustacea. 3. Ordination analysis of the invertebrate data showed that the four wetlands supported different invertebrate communities. However, species composition did not change completely along the ordination axes, suggesting that a relatively species‐poor invertebrate fauna was found in the wetlands. Taxa such as molluscs were restricted to wetlands with high pH. Multi‐response permutation procedures (MRPP) was used to analyse resultant ordination scores to see how they differed according to five terms: ‘Wetland’, ‘Habitat’, ‘Growth Form’, ‘Morphology’ and ‘Plant’. Most of the sample separation along ordination axes reflected differences between wetland, although the ‘Habitat’ and ‘Plant’ terms also explained some of the variation. The ‘Growth Form’ and ‘Morphology’ terms had only minor effects on community composition. 4. A multivariate regression tree modelled invertebrate assemblages according to the five predictor terms. The resultant model explained 54.8% of the species variance. The ‘Wetland’ term contributed most to the explanatory power, followed by ‘Habitat’. ‘Growth type’ and ‘Morphology’ explained only a small amount of variance to the regression tree, while the different plant species explained none of the variation. 5. Variation in these New Zealand wetland invertebrate communities appears to be controlled most by large‐scale factors operating at the level of individual wetlands, although different habitats within individual wetlands contributed slightly to this variation. Based on these results, sampling programmes to describe wetland invertebrate communities do not need to sample specific habitats or plant types within a wetland. Instead, samples can be collected from a wide range of habitats within individual wetlands, and pooled. Within each habitat, it is unnecessary to collect individual samples from different macrophytes or un‐vegetated areas. Our results suggest that collecting replicate pooled samples from different habitats within each wetland will be sufficient to characterize the invertebrate assemblage of each wetland.     

Seed Banks in Arid Wetlands with Contrasting Flooding,Salinity and Turbidity Regimes

Aquatic plant communities in arid zone wetlands underpin diverse fauna populations and ecosystem functions yet are relatively poorly known. Erratic flooding, drying, salinity and turbidity regimes contribute to habitat complexity, creating high spatial and temporal variability that supports high biodiversity. We compared seed bank density, species richness and community composition of aquatic plants (submergent, floating-leaved and emergent) among nine Australian arid zone wetlands. Germinable seed banks from wetlands within the Paroo and Bulloo River catchments were examined at nested scales (site, wetland, wetland type) using natural flooding and salinity regimes as factors with nondormant seed density and species richness as response variables. Salinity explained most of the variance in seed density (95%) and species richness (68%), with flooding accounting for 5% of variance in seed density and 32% in species richness. Salinity-flooding interactions were significant but explained only a trivial portion of the variance (<1%). Mean seed densities in wetlands ranged from 40 to 18,760 m⁻² and were highest in wetlands with intermediate levels of salinity and flooding. Variability of densities was high (CVs 0.61–2.66), particularly in saline temporary and fresh permanent wetlands. Below salinities of c. 30 g l⁻¹ TDS, seed density was negatively correlated to turbidity and connectivity. Total species richness of wetlands (6–27) was negatively correlated to salinity, pH and riverine connectivity. A total of 40 species germinated, comprising submergent (15 species), floating-leaved or amphibious (17 species), emergent (6 species) and terrestrial (6 species) groups. Charophytes were particularly important with 10 species (five Chara spp., four Nitella spp. and Lamprothamnium macropogon), accounting for 68% of total abundance. Saline temporary wetlands were dominated by Ruppia tuberosa, Lamprothamnium macropogon and Lepilaena preissii. Variable flooding and drying regimes profoundly altered water quality including salinity and turbidity, producing distinctive aquatic plant communities as reflected by their seed banks. This reinforces the importance of hydrology in shaping aquatic biological communities in arid systems.     

Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (<200 μeq l⁻¹) acid-neutralizing capacity (ANC) in southeastern Maine. We documented bird, pair, and brood use during 1982–1984 and in 1982 we sampled 10 wetlands with a sweep net to collect invertebrates. We related mean numbers of invertebrates per wetland to water chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver (Castor canadensis)-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH ≤ 5.51 (77.4%) in contract to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.     

Designing Wetlands for Amphibians: The Importance of Predatory Fish and Shallow Littoral Zones in Structuring of Amphibian Communities

Under section 401 and section 404 of the Clean Water Act, permission to degrade existing natural wetlands in the USA may be conditional on restoring or creating ‘replacement’ wetlands. Success of wetland mitigation efforts in adequately replacing lost wildlife habitats depends on our good understanding of key ecological attributes that affect the structure of wetland faunal communities. We examined the effects of the presence of predatory fish, shallow vegetated littoral zone, emergent vegetation cover, wetland age and size on amphibian diversity in 42 replacement wetlands located in the Ohio’s North Central Tillplain ecoregion. We recorded 13 species of pond-breeding amphibians, and the average local species richness (α-richness) was 4.2 ± 1.7 species per site (range 1–7). There is strong evidence for the positive association between amphibian species richness and presence of a shallow littoral zone, and the negative association with presence of predatory fish. There was no evidence for the association between species richness and age, size, amount of forest cover within 200 m, nor the amount of emergent vegetation cover at the study sites. It is estimated that local species richness in wetlands with shallows was 1.76 species higher on average than in wetlands without shallows (95% CI from 0.75 to 2.76). The presence of predatory fish was associated with an average reduction in species richness by an estimated 1.21 species (95% CI from 0.29 to 2.11). Replacement wetlands were placed in areas with little or no existing forest cover, and amphibian species associated with forested wetlands were either rare (eastern newt, spotted salamander) or not present at all (marbled salamander, wood frog). In addition, we surveyed all replacement wetlands constructed under section 401 in Ohio since 1990, and found that predatory fish were present in 52.4% of the sites and that shallows were absent from 42.7% of the sites. Our results indicate that current wetland replacement practices could have a negative effect on the amphibian diversity within our region.     

Avian Use of Wetlands in Reclaimed Minelands in Southwestern Indiana

We studied the use of mineland wetlands by birds and the relationship between avian communities and wetland characteristics. Data were collected from 20 wetlands in Pike County, Indiana, and included wetland size, depth, water conductivity and salinity, aquatic macroinvertebrate abundance, vegetation, and bird use. Principal component analysis showed that physical variables could be explained by two principal component scores and that wetlands could be grouped on the basis of size and conductivity. Principal component analysis could not reduce vegetation variables to fewer principal component scores, meaning that wetland vegetation characteristics were independent of one another and did not show any trend. Most wetlands had low invertebrate density, and wetlands with higher invertebrate density had low invertebrate diversity. Wetlands with similar habitat characteristics (physical, vegetative, and invertebrate) did not necessarily show similarities in bird assemblages. Bird similarity index values ranged from 0 to 59%, implying that each wetland has its own bird community. Stepwise multiple regression analysis (α= 0.05) relating bird use and habitat characteristics showed that bird species richness increased with the species richness of submergent vegetation and was correlated negatively with the species richness of emergent vegetation. There was no significant relationship between bird species richness or bird species diversity and wetland size. The number of species within different avian guilds correlated with different habitat characteristics. The species richness of submergent plants was a factor that correlated positively with the number of species of several guilds (dabblers, wading birds, and plunge divers). Wetland age was not a factor that determined bird use.     

Changes in the abundance and diversity of coastal wetland fauna from the open water/macrophyte edge towards shore

Great Lakes coastal wetlands are widely recognized as areas of concentrated biodiversity and productivity, but the factors that influence diversity and productivity within these systems are largely unknown. Several recent studies have suggested that the abundance and diversity of flora and fauna in coastal wetlands may be related to distance from the open water/macrophyte edge. We examined this possibility for three faunal groups inhabiting a coastal wetland in Saginaw Bay, Lake Huron. We sampled crustacean zooplankton and benthic macro-invertebrates at five distances from open water in the summer 1994, and fish at three distances from open water in 1994 and 1995. We found significant spatial trends in the total abundance and diversity of zooplankton and fish, as well as the diversity of benthic macro-invertebrates. Zooplankton abundance and taxa richness were highest at intermediate distances from open water in a transition zone between the well-mixed bayward portion of the wetland, and the non-circulating nearshore area. Benthic macro-invertebrate taxa richness increased linearly with distance from open water. In contrast, fish abundance and species richness declined linearly and substantially (abundance by 78%, species richness by 40%) with distance from open water. Of the 40 taxa examined in this study, 21 had significant horizontal trends in abundance. This led to notable differences in community composition throughout the wetland. Our results suggest that distance from open water may be a primary determinant of the spatial distributions of numerous organismal groups inhabiting this coastal wetland. Several possible reasons for these distributions are discussed.     

Species‐specific responses to wetland mitigation among amphibians in the Greater Yellowstone Ecosystem

Habitat loss and degradation are leading causes of biodiversity declines, therefore assessing the capacity of created mitigation wetlands to replace habitat for wildlife has become a management priority. We used single season occupancy models to compare the occurrence of larvae of four species of pond‐breeding amphibians in wetlands created for mitigation, wetlands impacted by road construction, and unimpacted reference wetlands along a highway corridor in the Greater Yellowstone Ecosystem, United States. Created wetlands were shallow and had less aquatic vegetation and surface area than impacted and reference wetlands. Occupancy of barred tiger salamander (Ambystoma mavortium) and boreal chorus frog (Pseudacris maculata) larvae was similar across wetland types, whereas boreal toads (Anaxyrus boreas) occurred more often in created wetlands than reference and impacted wetlands. However, the majority of created wetlands (>80%) dried partially or completely before amphibian metamorphosis occurred in both years of our study, resulting in heavy mortality of larvae and, we suspect, little to no recruitment. Columbia spotted frogs (Rana luteiventris), which require emergent vegetation that is not common in newly created wetlands, occurred commonly in impacted and reference wetlands but were found in only one created wetland. Our results show that shallow created wetlands with little aquatic vegetation may be attractive breeding areas for some amphibians, but may result in high mortality and little recruitment if they fail to hold water for the entire larval period.     

Vegetation Communities of 20-year-old Created Depressional Wetlands

Many studies have chronicled the early development of vegetation in wetlands created as mitigation for wetland impacts; however, very few studies have followed the floristics of wetlands that are more than 10 years post-creation. This article reports the results of vegetation composition and structural analysis within eleven 20-yr-old created non-tidal, emergent wetlands. Vegetation and inundation were sampled in 173 plots within 11 wetlands during the 1992 and 1994 growing seasons. A drought occurred in 1993, thus analyses characterized vegetative response and included weighted average (weighted by the tolerance of the species to excess soil moisture), species richness, species composition, and life history strategy. Weighted average and species richness increased in 7 and 10 of the 11 sites, respectively. There was little change among most species including Typha latifolia and Scirpus cyperinus, the two species with highest importance values (IV). However, among the top 10 species ranked by IV, two aquatic species decreased and a facultative species increased. Only one of the 10 most important species, Eleocharis obtusa, was an annual and only one, Salix nigra, was a woody perennial and the IV of both species declined during the study. After 20 years, a transition from annual to perennial graminoid life histories is suggested; however, succession from emergent to shrub–scrub or forested wetland is not indicated.     

Wetland Selection by Mallard Broods in Canada's Prairie-Parklands

ABSTRACT Although brood survival has a pronounced effect on population growth in mallards (Anas platyrhynchos), knowledge of brood ecology is more limited than for other vital rates. During 1993–1997 we collected wetland selection data from 210 radiomarked mallard broods on 15 study areas located throughout the Canadian Prairie-Parklands. We used information-theoretic approaches to select the best-approximating model of habitat selection in relation to wetland characteristics. Wetland permanence, cover type, width of flooded emergent vegetation, and interactions between these variables and date, moisture level, and dominant species of emergent vegetation were all important predictors of wetland selection. Mallard broods selected deeper wetlands, especially later in the brood-rearing season. Mallard broods also selected wetlands with large central expanses of open water and wide peripheral zones of flooded emergent cover. These habitat characteristics can most easily be met in landscapes that already contain an abundance and diversity of natural wetland habitats. Where such wetlands are unavailable, restoration or management of deeper wetlands may be necessary to meet the habitat requirements of mallard ducklings.     

Restoration of Freshwater Intertidal Habitat Functions at Spencer Island, Everett, Washington

In November 1994 dikes were breached around Spencer Island, restoring tidal inundation and connections to the Snohomish River estuary, Washington. Approximately 23.7 ha (58.5 ac) of palustrine wetlands previously dominated by Phalaris arundinacea (reed canarygrass) now experience diurnal tides and are in the process of transition to a freshwater tidal system. It was expected that brackish water would accompany the return of tidal influence to the site, but post‐project monitoring has revealed little evidence of salinity. Pre‐ and post‐project monitoring of changes in habitat function included aerial photography, vegetation and fish sampling, and benthic prey studies. To date site changes include (1) die back of pre‐project vegetation, development of tidal mudflat, and emergent wetland habitats, with recruitment of vegetation typical of freshwater tidal wetlands; (2) presence of juvenile coho, chum, and chinook salmon that feed on invertebrate prey typical of the site; (3) presence of three distinct benthic invertebrate assemblages in the project area; and (4) some invasion by Lythrum salicaria (purple loosestrife). The unexpected freshwater conditions, the lack of published information about tidal oligohaline marshes in the Pacific Northwest, the use of the site by endangered salmonid species, and the invasion by an undesired plant species underscore the importance of long‐term monitoring at the site.     

Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

This study examined the use of freshwater wetland restoration and enhancement projects ( i.e . non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement ( i.e . addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi . Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.     

Comparison of created and natural freshwater emergent wetlands in Connecticut (USA)

Five three- to four-year old created palustrine/emergent wetland sites were compared with five nearby natural wetlands of comparable size and type. Hydrologic, soil and vegetation data were compiled over a nearly two-year period (1988-90). Created sites, which were located along major highways, exhibited more open water, greater water depth, and greater fluctuation in water depth than natural wetlands. Typical wetland soils exhibiting mottling and organic accumulation were wanting in created sites as compared with natural sites. Typha latifolia (common cattail) was the characteristic emergent vegetation at created sites, whereas a more diverse mosaic of emergent wetland species was often associated with Typha at the natural sites. Species richness was slightly higher in created (22–45) vs. natural (20–39) wetlands, but the mean difference (33 vs. 30) was not significant. Nearly half (44%) of the 54 wetland taxa found at the various study sites were more frequently recorded at created than natural wetlands. The presence of mycorrhizae in roots of Typha angustifolia (narrow-leaved cattail) and Phragmites australis (common reed) was greater at created than natural wetlands, which may be related to differential nutrient availability. Wildlife use at all sites ranged from occasional to rare, with more sightings of different species in the natural (39) than created (29) wetlands. The presence of P. australis and introduced Lythrum salicaria (purple loosestrife) may pose a threat to future species richness at the created sites. One created site has permanent flow-through hydrology, and its vegetation and wildlife somewhat mimic a natural wetland; however, the presence of P. australis and its potential spread pose an uncertain future for this site. This study suggests the possibility of creating small palustrine/emergent wetlands having certain functions associated with natural wetlands, such as flood water storage, sediment accretion and wildlife habitat. It is premature to evaluate fully the outcome of these wetland creation efforts. A decade or more is needed, emphasizing the importance of long term monitoring and the need to establish demonstration areas.     

Urban bat communities are affected by wetland size,quality, and pollution levels

Wetlands support unique biota and provide important ecosystem services. These services are highly threatened due to the rate of loss and relative rarity of wetlands in most landscapes, an issue that is exacerbated in highly modified urban environments. Despite this, critical ecological knowledge is currently lacking for many wetland‐dependent taxa, such as insectivorous bats, which can persist in urban areas if their habitats are managed appropriately. Here, we use a novel paired landscape approach to investigate the role of wetlands in urban bat conservation and examine local and landscape factors driving bat species richness and activity. We acoustically monitored bat activity at 58 urban wetlands and 35 nonwetland sites (ecologically similar sites without free‐standing water) in the greater Melbourne area, southeastern Australia. We analyzed bat species richness and activity patterns using generalized linear mixed‐effects models. We found that the presence of water in urban Melbourne was an important driver of bat species richness and activity at a landscape scale. Increasing distance to bushland and increasing levels of heavy metal pollution within the waterbody also negatively influenced bat richness and individual species activity. Areas with high levels of artificial night light had reduced bat species richness, and reduced activity for all species except those adapted to urban areas, such as the White‐striped free‐tailed bat (Austronomus australis). Increased surrounding tree cover and wetland size had a positive effect on bat species richness. Our findings indicate that wetlands form critical habitats for insectivorous bats in urban environments. Large, unlit, and unpolluted wetlands flanked by high tree cover in close proximity to bushland contribute most to the richness of the bat community. Our findings clarify the role of wetlands for insectivorous bats in urban areas and will also allow for the preservation, construction, and management of wetlands that maximize conservation outcomes for urban bats and possibly other wetland‐dependent and nocturnal fauna.     

Wetland development in a previously mined landscape of East Texas,USA

We studied wetland development in a chronosequence of created wetlands in a reclaimed landscape in east Texas seasonally for 1 year. The purpose of the study was to identify features (i.e., indicators) that best reflected changes in wetland ecosystem state through time and could serve as indicators of “maturity” for bond-release. Features considered included surface water nutrients, soil nutrients, soil redox potential, vegetative biomass and diversity, and benthic invertebrate biomass and diversity. Our sampling focused on nine wetlands representing three different-age classes (n = 3 for each) as a surrogate for time. All wetland sites were created with the same homogenized mine spoil and had similar hydrology and climate. Age-specific changes in all parameters were observed, except for surface water nutrients. The oldest wetlands (i.e., “mature”) exhibited highest soil concentrations of N, C, K, P, and Ca. Soil redox potential was significantly lower in the mature wetlands, in addition to within-wetland (lowest in deepest sampling zones) and intra-annual variability (i.e., lowest during the summer). Mature created wetlands supported the highest vegetative biomass and species richness and highest densities of invertebrates; however, taxa richness was similar across all age groups. Of all parameters we measured, vegetation metrics were among the simplest and most cost-effective measures used to track the early development of mitigated wetlands. This study provides the basis from which to track the development of these reclaimed ecosystems in a more rigorous and easily replicated manner. With further validation, select use of these parameter sets in east Texas and other similar landscapes could aid both in determining compliance for regulatory purposes as well as tracking success of ecological mitigation.