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SPECIAL SESSION: Impact of Environmental Changes on Nematode Communities and Soil Health

Changing ecosystems - Plant succession effects on soil diversity and function
Dorota Porazinska - Entomology and Nematology, University of Florida.

Climate warming is a key factor driving range shifts of species. Most work has been focused on shifts of aboveground plant communities, but changes in vegetation can trigger parallel shifts in in soil communities with consequences on ecosystem-level nutrient cycle budgets and ecosystem functioning.

High alpine ecosystems are particularly sensitive to climate warming because snow, one of the fastest changing climate features, is the main driver of ecosystem structure and function. Consistent with global patterns, long-term snow cover changes (a thinner and less isolating snow cover that develops later and melts earlier) at the Niwot Ridge in the Colorado Rocky Mountains have resulted in a slow but consistent migration of plants into higher elevations generating a mosaic of habitats ranging from originally free of plants to increasingly vegetated. We used this natural experiment to examine climate-driven shifts of plants and soil communities and their role in shifts of soil carbon and nitrogen dynamics.

The main hypothesis was that snow cover would be the driving factor of plant communities (less snow – more plants) that in turn drive soil communities (i.e., including nematodes) (more plants – more soil biota) that together drive soil C and N up. In addition, we predicted that positive relationships would be particularly evident for plant pathogens and parasites.