In summer 2011, Tropical storms Lee and Irene caused an estimated 90% decline of the submersed aquatic plant Michx. (Hydrocharitaceae) in the Hudson River of New York (USA). To understand the genetic impact of such large-scale demographic losses, we compared diversity at 10 microsatellite loci in 135 samples collected from five sites just before the storms with 239 shoots collected from nine sites 4 years after.
View Article and Find Full Text PDFConsiderable progress has been made in ecological and evolutionary genetics with studies demonstrating how genes underlying plant and microbial traits can influence adaptation and even 'extend' to influence community structure and ecosystem level processes. Progress in this area is limited to model systems with deep genetic and genomic resources that often have negligible ecological impact or interest. Thus, important linkages between genetic adaptations and their consequences at organismal and ecological scales are often lacking.
View Article and Find Full Text PDFTidal habitats host a diversity of species and provide hydrological services such as shoreline protection and nutrient attenuation. Accretion of sediment and biomass enables tidal marshes and swamps to grow vertically, providing a degree of resilience to rising sea levels. Even if accelerating sea level rise overcomes this vertical resilience, tidal habitats have the potential to migrate inland as they continue to occupy land that falls within the new tide range elevations.
View Article and Find Full Text PDFThe maintenance of marsh platform elevation under conditions of sea level rise is dependent on mineral sediment supply to marsh surfaces and conversion of above- and belowground plant biomass to soil organic material. These physical and biological processes interact within the tidal zone, resulting in elevation-dependent processes contributing to marsh accretion. Here, we explore spatial pattern in a variable related to aboveground biomass, plant litter, to reveal its role in the maintenance of marsh surfaces.
View Article and Find Full Text PDFDifferences in body sizes may create a trade-off between foraging efficiency (foraging gains/costs) and access to resources. Such a trade-off provides a potential mechanism for ecologically similar species to coexist on one resource. We explored this hypothesis for tundra (Cygnus columbianus) and trumpeter swans (Cygnus buccinator), a federally protected species, feeding solely on sago pondweed (Stuckenia pectinata) tubers during fall staging and wintering in northern Utah.
View Article and Find Full Text PDFVallisneria americana Michaux (wild celery) is currently a target of submersed aquatic vegetation restoration efforts in the Chesapeake Bay watershed. To aid these efforts, we have developed 11 polymorphic microsatellite markers to assess the distribution and degree of genetic diversity in both restored and naturally occurring populations in the Chesapeake Bay. In 59 individuals from two populations, we detected two to 10 total alleles per locus.
View Article and Find Full Text PDFLandscape fragmentation and exotic species invasions are two modern-day forces that have strong and largely irreversible effects on native diversity worldwide. The spatial arrangement of habitat fragments is critical in affecting movement of individuals through a landscape, but little is known about how invasive species respond to landscape configuration relative to native species. This information is crucial for managing the global threat of invasive species spread.
View Article and Find Full Text PDFThe restoration of degraded systems is essential for maintaining the provision of valuable ecosystem services, including the maintenance of aesthetic values. However, restoration projects often fail to reach desired goals for a variety of ecologic, financial, and social reasons. Feasibility studies that evaluate whether a restoration effort should even be attempted can enhance restoration success by highlighting potential pitfalls and gaps in knowledge before the design phase of a restoration.
View Article and Find Full Text PDFReliably predicting the consequences of short- or long-term changes in the environment is important as anthropogenic pressures are increasingly stressing the world's ecosystems. One approach is to examine the manner in which biota respond to changes in the environment ("response traits") and how biota, in turn, affect ecosystem processes ("effect traits"). I compared the response and effect traits of four submersed aquatic macrophytes to understand how water level management may affect wetland plant populations and ecosystem processes.
View Article and Find Full Text PDFRapid changes in biodiversity are occurring globally, yet the ecological impacts of diversity loss are poorly understood. Here we use data from marine invertebrate communities to parameterize models that predict how extinctions will affect sediment bioturbation, a process vital to the persistence of aquatic communities. We show that species extinction is generally expected to reduce bioturbation, but the magnitude of reduction depends on how the functional traits of individual species covary with their risk of extinction.
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