Career Links Page for Marcus W. Griswold

My research has focused primarily on the impact of land management practices (e.g., riparian buffer zones) on small headwater streams in Costa Rica and the southeastern United States. I am primarily interested in the consequences of landscape alterations on water quality and biota, as well as the community and population level responses of aquatic and terrestrial biota to human disturbances. My dissertation research utilizes a paired watershed study to evaluate the effectiveness of Georgia's Best Management Practices for logging near streams. Specifically, I study the impacts of various logging regimes on the community and behavioral responses of aquatic macroinvertebrates, particularly with regards to changes in habitat quality and quantity. As part of this five-year study, I regularly collaborate with hydrologists and wildlife biologists to understand the complex responses of multiple trophic levels to a range of environmental parameters. My work in Costa Rica expands on my dissertation project by linking food web structure to land use management along a gradient of riparian zone quality, from pasture to primary forest, in lowland tropical streams. These studies rely on stable isotopes and biodiversity as indicators of disturbance. Preliminary data show that in both cases, natural disturbances (e.g., drought) potentially altered the impact of the anthropogenic disturbance. Future studies would seek to understand how aquatic ecosystems recover and adapt to natural and anthropogenic disturbances. This research would be highly relevant within the climate change framework, as current models predict that frequent periods of natural disturbances are likely in the future.


In addition to working in watersheds managed for forestry, I also collaborate with colleagues to understand the impacts of urbanization on riparian zone quality and stream communities. This work examines the impact of road crossings over streams on the upstreams and downstream invertebrate communities in relation to geomorphology, heavy metal deposition, and sediment and organic matter dynamics.