Microbial drivers of methane emissions from unrestored industrial salt ponds

Wetlands are important carbon (C) sinks, yet many have been destroyed and converted to other uses over the past few centuries, including industrial salt making. A renewed focus on wetland ecosystem services (e.g., flood control, and habitat) has resulted in numerous restoration efforts whose effect on microbial communities is largely unexplored. We investigated the impact of restoration on microbial community composition, metabolic functional potential, and methane flux by analyzing sediment cores from two unrestored former industrial salt ponds, a restored former industrial salt pond, and a reference wetland. We observed elevated methane emissions from unrestored salt ponds compared to the restored and reference wetlands, which was positively correlated with salinity and sulfate across all samples. 16S rRNA gene amplicon and shotgun metagenomic data revealed that the restored salt pond harbored communities more phylogenetically and functionally similar to the reference wetland than to unrestored ponds. Archaeal methanogenesis genes were positively correlated with methane flux, as were genes encoding enzymes for bacterial methylphosphonate degradation, suggesting methane is generated both from bacterial methylphosphonate degradation and archaeal methanogenesis in these sites. These observations demonstrate that restoration effectively converted industrial salt pond microbial communities back to compositions more similar to reference wetlands and lowered salinities, sulfate concentrations, and methane emissions.

Public–Private Partnership Wetland Restorations Provide Quality Forage for Waterfowl in Northern New York

The Partners for Fish and Wildlife Program and Wetlands Reserve Program are U.S. federal programs that provide financial and technical assistance to restore wetland habitats on private property, and are important tools for the conservation and management of waterfowl. This study examined whether these wetland restorations successfully restored one important component of waterfowl habitat, the availability of vegetative forage, at sites in the St. Lawrence River valley of New York. We conducted surveys at 47 restored and 18 reference wetlands to characterize the vegetation assemblage in terms of its value as forage for waterfowl. Results suggest that these public–private partnership wetland restorations develop assemblages of wetland vegetation that are similar to reference wetlands. Vegetation assemblage metrics, including estimates of species richness, the richness of species of food value, the Vegetative Forage Quality Index, and the cover of species of food value, did not differ between restored–reference wetland pairs. However, invasive species were common at sites, and we detected a negative association between the cover of invasive species and the Vegetative Forage Quality Index at both restored and reference wetlands. On the basis of these results, we conclude that Partners for Fish and Wildlife Program and Wetland Reserve Program wetland restorations provide quality forage for breeding and migratory waterfowl in this region, but that the presence of invasive vegetation at sites has the potential to decrease the quality of vegetative forage at sites over time.

Sand quarry wetlands provide high-quality habitat for native amphibians

Anthropogenic disturbances to habitats influence the fitness of individual animals, the abundance of their populations, and the composition of their communities. Wetlands in particular are frequently degraded and destroyed, impacting the animals that inhabit these important ecosystems. The creation of wetlands during and following sand extraction processes is inevitable, and thus, sand quarries have the potential to support aquatic animals. To determine how amphibians utilise these wetlands, I conducted nocturnal call surveys at wetlands within the Kables Sands quarry, New South Wales, Australia, and within surrounding reference wetlands, and quantified levels of developmental instability (DI) as a proxy for fitness. Whilst quarry and reference wetlands were largely similar in terms of environmental characteristics, quarry wetlands consistently harboured more amphibian species and individuals. Using unsigned asymmetry as a measure of DI, frogs from the quarry sites exhibited significantly lower levels of DI compared to reference wetlands, indicating that quarry wetlands may be comparatively higher quality. Levels of DI within quarry wetlands also compared favourably to data from healthy frog populations extracted from the literature. Further enhancing the suitability of quarry wetlands would require minimal effort, with potentially significant increases in local and regional biodiversity. Documenting species presence and quantifying individual fitness by measuring limb lengths is an economically and logistically feasible method to assess the health of quarry wetlands. Overall, the methods outlined here provide a powerful, yet simple, tool to assess the overall health and suitability of quarry wetlands that could be easily adopted at quarries throughout the world.