Feedback Between Plants and Soil Microbes in Serpentine and Prairie Grasslands

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

Feedback between plants and soil microbes in serpentine and prairie grasslands This research investigates whether the relationships between certain grass species and their mycorrhizal fungi play a role in maintaining plant species diversity in natural communities. Mycorrhizal fungi generally form mutually beneficial associations with plant roots. Plants supply the fungi with sugars and, in return, receive benefits that include increased uptake of water and nutrients, and in some cases, increased ability to cope with toxic metals. Recent studies have documented negative feedback between different mycorrhizal fungi and different plant species, where the fungi associated with a particular plant species do not provide as much benefit to that plant species as do fungi associated with other plant species in the community. Consequently, when one plant dies and its mycorrhizal fungi and any associated pathogenic fungi remain in the soil, that plant is likely to be replaced by a different plant species, thereby promoting species diversity. This work builds on negative feedback found in a grassland on serpentine soil, which naturally has a high heavy metal content. Negative feedback will be further explored at that site and in the tallgrass prairie, where these same grasses occur. Results may also help in developing mycorrhizal fungi that facilitate remediation of soils polluted with heavy metals.