Using environmental DNA to inform biodiversity conservation in agricultural landscapes
Reves, Olivia P.
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/130031
Description
Title
Using environmental DNA to inform biodiversity conservation in agricultural landscapes
Author(s)
Reves, Olivia P.
Issue Date
2025-07-14
Director of Research (if dissertation) or Advisor (if thesis)
Larson, Eric R
Committee Member(s)
Davis, Mark A
Stickley, Samuel F
Department of Study
Natural Res & Env Sci
Discipline
Natural Res & Env Sciences
Degree Granting Institution
University of Illinois Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Keyword(s)
agricultural conservation
biodiversity
eDNA
environmental DNA
Illinois
metabarcoding
riparian buffers
stream flow
vertebrates
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 (U.S.) has experienced agricultural intensification and expansion, resulting in losses of native tallgrass prairies, wetlands, and forests. To mitigate agricultural pressures, conservation practices have been widely implemented across the Midwest. As a result, forest cover in Midwestern states like Illinois has increased over the last several decades partially due to agricultural conservation practices like riparian buffers, which can improve water quality, alleviate nutrient transfer and reduce soil loss. While the benefits of riparian buffers to aquatic taxa are well-documented, benefits to terrestrial biodiversity are less understood. To monitor wildlife across taxa, a combination of conventional methods can be costly, time-consuming and invasive. Environmental DNA (eDNA), DNA collected and isolated from environmental samples, can provide a solution to this challenge. Further, rivers have proven to be conveyor belts of not only aquatic DNA but also terrestrial eDNA as well from upstream or adjacent riparian areas. Among many factors that can influence eDNA dynamics in a river, precipitation can either dilute eDNA due to increasing discharge or mobilize eDNA into rivers from adjacent riparian terrestrial ecosystems. For my first study, I sampled three rivers before and after precipitation events in the Vermilion River watershed of east-central Illinois to evaluate if terrestrial DNA exhibits a mobilization effect and if aquatic eDNA exhibits a dilution effect in response to rainfall. I found that rainfall had a positive, significant effect on terrestrial taxa richness and a negative, non-significant effect on aquatic taxa richness. This study not only advances eDNA applications for vertebrate community analysis but also informs future eDNA sampling efforts for detecting terrestrial and aquatic taxa from lotic environments. For my second study, I collected eDNA samples from streams across a forest cover gradient in central Illinois to quantify the terrestrial biodiversity co-benefit of riparian buffers, a proposed agricultural conservation practice for the Midwest, to terrestrial wildlife. I demonstrated that sites with complete (100%) riparian buffers can support three times the terrestrial vertebrate taxa richness compared to sites lacking buffers entirely, with highly forested sites harboring unique forest-associated communities. This study demonstrates the benefit of riparian buffers to terrestrial wildlife and validates eDNA as a rapid biomonitoring tool to assess biodiversity responses to agricultural conservation practices. Collectively, my thesis research seeks to support biodiversity conservation across agricultural landscapes.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
