Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Threats to aquatic taxa in an arid landscape: knowledge gaps and areas of understanding for amphibians of the American southwest.

Abstract

The American Southwest is a dryland region with variable, seasonal precipitation, and a wide range of freshwater habitats. Amphibians are among the diverse freshwater taxa that rely on aquatic habitats of the southwest, yet the state-of-the-science regarding vulnerability of the region's amphibians to threats recognized globally is unclear. To address this knowledge gap, we reviewed 81 publications and 341 species:threat relationships to assess coverage in the peer-reviewed literature of potential threats to 35 amphibians native to the region. We classified threats into three major categories: climate change, biological, and land use. Using a new trait database for anurans (frogs and toads) of the United States, we evaluated these threats in the context of life history diversity of the region's anurans. We found high coverage for hydrological alteration and introduced species as well as changes to community dynamics, land use, and precipitation. Other potential threats-particularly those linked to climate change such as changes in seasonality and fire-had comparatively low coverage. Coverage varied widely among species, with the number of reported species:threat relationships ranging from 37 (the lowland leopard frog, Lithobates yavapaiensis) to no coverage for some species-including some of conservation concern (e.g., Sacramento Mountains salamander, Aneides hardii). Our findings support leveraging available information to test hypothesized linkages between amphibian life histories and risk and response to threats; using high coverage species and threats to inform simulations and experiments exploring species:threat relationships and efficacy of management strategies; and addressing knowledge gaps for species and threats with no proxies through on-the-ground natural history efforts.