Annie Young-Mathews, Steve Culman, Louise Jackson, Shabeg Briar, Sara Sanchez-Moreno, Howard Ferris, Toby O’Geen, Kate Scow

This project is focused on the effects of riparian management and land use on the community composition and diversity of soil microbes, nematodes and plants, and the ability of soils to retain nutrients and store carbon.  The study area is an agricultural landscape located in western Yolo County in California’s Central Valley, with a gradient of land use intensity going from irrigated row crop agriculture in the east to grazed upland grasslands in the west.

Preliminary results show that land use in this highly disturbed landscape has a more significant influence on biodiversity and soil nutrient pools than distance from a waterway.  However, healthy riparian zones harbored more diversity and more highly structured soil communities than highly disturbed riparian zones.  Interestingly however, high aboveground plant diversity did not necessarily correlate with increased belowground microbial and nematode diversity, possibly due to the history of disturbance and lack of remnant populations for recolonization.

A related farmscape-scale project in the same region looked at the effects of riparian restoration (widening of the floodplain bench and revegetation with native grasses, shrubs and trees) on nematode community structure and diversity as a way to examine soil food web condition.  The study also examined the effects of restoration on greenhouse gas emissions, soil nutrient retention to prevent water quality degradation, control of noxious weeds, and carbon storage in soil and woody species.