Project Title

Natural and Anthropogenic Drivers of Stream Macroinvertebrate Diversity over time in Georgia, USA

Academic department under which the project should be listed

CSM - Ecology, Evolution, and Organismal Biology

Faculty Sponsor Name

Nicholas Green

No human subjects

Abstract (300 words maximum)

We investigated how aquatic macroinvertebrate communities in streams of Georgia, USA, changed over time in relation to trends in land use and human activities within watersheds. Stream organisms respond to natural and human influences at multiple spatial and temporal scales. The state of Georgia, USA, has approximately 70,000 km of perennial streams and rivers in 53 USGS HUC8 watersheds. These streams cross land at 0 to >1400 m elevation, across 6 EPA level III ecoregions, and a wide range of land use types. Stream biodiversity is an important indicator of overall watershed and stream health. Understanding how different factors influence stream organisms across spatial and temporal scales is crucial for conservation of aquatic communities and ecosystems, as well as promoting water quality. We integrated data from a state-wide biomonitoring program (Georgia Environmental Monitoring and Assessment System) collected 2000-2018 with public spatial data characterizing the hydrology, land cover, human population density, and other factors within the sampled watersheds. The dataset included 496 sampling sites in every major watershed. We then used boosted regression trees to identify environmental drivers of stream biodiversity while accounting for nonlinearity and interactions between predictors. Our primary hypothesis is that stream biodiversity will decrease over time, with greater decline in watersheds with more intensive human land use. Our results will identify anthropogenic impacts on Georgia stream biota in their spatial and temporal context. This is critical as human land use intensifies (e.g., suburban and urban development) and these effects interact with pre-existing natural gradients such as elevation and latitude. Our findings have the potential to inform science-based management of Georgia streams for biodiversity conservation.

Project Type

Event

This document is currently not available here.

Share

COinS
 

Natural and Anthropogenic Drivers of Stream Macroinvertebrate Diversity over time in Georgia, USA

We investigated how aquatic macroinvertebrate communities in streams of Georgia, USA, changed over time in relation to trends in land use and human activities within watersheds. Stream organisms respond to natural and human influences at multiple spatial and temporal scales. The state of Georgia, USA, has approximately 70,000 km of perennial streams and rivers in 53 USGS HUC8 watersheds. These streams cross land at 0 to >1400 m elevation, across 6 EPA level III ecoregions, and a wide range of land use types. Stream biodiversity is an important indicator of overall watershed and stream health. Understanding how different factors influence stream organisms across spatial and temporal scales is crucial for conservation of aquatic communities and ecosystems, as well as promoting water quality. We integrated data from a state-wide biomonitoring program (Georgia Environmental Monitoring and Assessment System) collected 2000-2018 with public spatial data characterizing the hydrology, land cover, human population density, and other factors within the sampled watersheds. The dataset included 496 sampling sites in every major watershed. We then used boosted regression trees to identify environmental drivers of stream biodiversity while accounting for nonlinearity and interactions between predictors. Our primary hypothesis is that stream biodiversity will decrease over time, with greater decline in watersheds with more intensive human land use. Our results will identify anthropogenic impacts on Georgia stream biota in their spatial and temporal context. This is critical as human land use intensifies (e.g., suburban and urban development) and these effects interact with pre-existing natural gradients such as elevation and latitude. Our findings have the potential to inform science-based management of Georgia streams for biodiversity conservation.