Data from: Genetic signatures of ecological diversity along an urbanization gradient

Despite decades of work in environmental science and ecology, estimating
human influences on ecosystems remains challenging. This is partly due to
complex chains of causation among ecosystem elements, exacerbated by the
difficulty of collecting biological data at sufficient spatial, temporal,
and taxonomic scales. Here, we demonstrate the utility of environmental
DNA (eDNA) for quantifying associations between human land use and changes
in an adjacent ecosystem. We analyze metazoan eDNA sequences from water
sampled in nearshore marine eelgrass communities and assess the
relationship between these ecological communities and the degree of
urbanization in the surrounding watershed. Counter to conventional wisdom,
we find strongly increasing richness and decreasing beta diversity with
greater urbanization, and similar trends in the diversity of life
histories with urbanization. We also find evidence that urbanization
influences nearshore communities at local (hundreds of meters) rather than
regional (tens of km) scales. Given that different survey methods sample
different components of an ecosystem, we then discuss the advantages of
eDNA—which we use here to detect hundreds of taxa simultaneously—as a
complement to traditional ecological sampling, particularly in the context
of broad ecological assessments where exhaustive manual sampling is
impractical. Genetic data are a powerful means of uncovering
human-ecosystem interactions that might otherwise remain hidden;
nevertheless, no sampling method reveals the whole of a biological
community.