AUTHORS: Olivia P. Reves, Department of Natural Resources and Environmental Sciences, University of Illinois Urbana-Champaign, Urbana, IL, USA; Mark A. Davis, Illinois Natural History Survey, Prairie Research Institute, University of Illinois Urbana-Champaign, Champaign, IL, USA; Eric R. Larson, Department of Natural Resources and Environmental Sciences, University of Illinois Urbana-Champaign, Urbana, IL, USA
ABSTRACT: The conversion of natural ecosystems to agriculture is a leading cause of habitat loss and threatens global biodiversity. For the past two centuries, the midwestern United States has experienced agricultural intensification and expansion, resulting in losses of natural ecosystems including tallgrass prairies, wetlands, and forests. Forest cover in states like Illinois has increased over the last several decades, partially due to agricultural conservation efforts like agroforestry, the Conservation Reserve Enhancement Program, and implementation of riparian buffers. However, does this increasing forest cover, intended to reduce nutrient and soil loss and benefit in-stream biota, also have benefits to terrestrial biodiversity? We used environmental DNA (eDNA), DNA collected and isolated from environmental samples, to evaluate how forest cover influences and potentially benefits terrestrial and semi-aquatic vertebrates in agricultural landscapes. In May and June of 2024, we collected eDNA samples from 47 low order streams over gradients of both riparian and whole-watershed forest cover from the U.S. National Land Cover Database. We then conducted eDNA metabarcoding of vertebrate communities using 12S and COI primers. Next, we used generalized linear mixed models to examine effects of forest cover on species richness, as well as non-metric multidimensional scaling to explore differences in community composition between sites of varying forest cover. Evaluating how terrestrial vertebrate communities respond to forest cover can shape management practices from riparian buffers to watershed-wide scales across agricultural regions.
