2020 | Plant-Microbe Interactions

FACULTY SEED GRANT | Global Change Center

Using a global weed to disentangle environment and host effects on plant-microbe interactions across nested spatial scales

INVESTIGATORS:

• Dr. Bryan Brown, Biological Sciences
• Dr. Brian Badgley, School of Plant and Environmental Sciences
• Dr. Jacob Barney, School of Plant and Environmental Sciences
• Dr. David Haak, School of Plant and Environmental Sciences

Declining stream health due to agricultural pollution is a major global issue requiring interdisciplinary solutions. Agricultural pollution (e.g., sediment) adversely affects biodiversity,  and ecosystem services — key components of stream health. Farmers often partner with government agencies through cost-share agreements to apply best management practices (BMPs) to improve stream health while continuing food production. Although ≈ 65,000 BMPs have been applied in the Powell, Clinch, and Holston watersheds of southwest VA, water quality goals in many locations remain unmet. These shortfalls can arise from varying BMP efficacy due to interactions among watershed features, BMP types and locations, and ecological responses along hydrological flow paths. Biophysical processes are also influenced by social processes, including the socioeconomic factors driving land-use decisions.

Therefore, improving stream health requires integrating social science, watershed modeling, and ecology.  Most research on BMP efficacy focuses on ecological or hydrological — not social — aspects.  However, because farmers participate in BMP programs voluntarily, social science is crucial to understanding efficacy at watershed scales. Social science contributes to conservation through  justifying actions, improving management practices, and helping achieve ecological outcomes. For BMP efficacy, social science can clarify factors influencing participation in cost-share programs, which  can inform outreach to increase participation. Landowners participate in BMP programs by a)  entering cost-share agreements (i.e., adoption) or b) continuing or maintaining conservation practices after agreements end (i.e., persistence). 

Although persistence is important for maintaining environmental benefits of BMPs, most agency  programs focus on adoption. Persistence includes maintenance of structural BMPs or reimplementation of management BMPs. Maintained structural BMPs more effectively decrease sediment loads to  streams than unmaintained BMPs. Unfortunately, landowners often revert to prior land management when cost-share contracts end, thereby losing BMP-induced ecological benefits (e.g.,  fallen fencing that no longer excludes cattle from streams). A clearer understanding of landowner and  BMP persistence (i.e., rates and drivers) could help agencies assess the importance of promoting new  BMPs versus maintaining existing BMPs in achieving water-quality goals. 

Our team will integrate social science, watershed modeling, and ecology to develop and test a novel model to explain BMP efficacy. We will build on current work, funded by Natural Resources Conservation Service (NRCS), that models pollutant yields to streams,  measures water quality, and collects macroinvertebrates as indicators of stream health. This work lacks the social science needed to fully understand BMP efficacy. Herein, we propose to survey landowners to achieve three objectives complementing our current work: 1) assess persistence, 2) determine landowner attributes influencing persistence, and 3) compare effects of watershed features, water  quality, and BMP implementation on stream health. Coupling current and proposed work would provide a sound basis for more expansive proposals (e.g., to NRCS or National Institute of Food and  Agriculture) to examine how interactions between ecological and social processes determine land management. 

Reference citations for project proposal description available upon request.