ARS/SCA: McCulley FAPRU-SCA Award

Managed grasslands, a.k.a. pastures, cover significant land area in the eastern U.S. and are important economically, as the base of animal production systems (Sheaffer et al. 2009). They are also important for regional nutrient cycling and the maintenance of overall environmental quality and ecosystem services (Singer et al. 2009). Future changes in the physical environment associated with climate change are likely to interact with management practices, such as the adoption of new genetic material and endophyte associations, to alter both the quantity and the quality of the forage these ecosystems provide (Izaurralde et al. 2011). Yet little is known regarding how forage species will respond to changing climate. Utilizing an existing manipulative, climate change experiment, this project will examine how elevated temperature (+3oC) and altered growing season precipitation affect managed grassland plant communities, forage production, and forage quality. By transplanting genetically identical, ramet/tiller clone pairs of tall fescue (each pair consists of an endopohyte-infected and endophyte-free individual) and other grass species into the forage climate change experiment, this project will evaluate the plant genotype-endophyte symbiosis-environment interaction on plant growth, rates of photosynthesis and associated ecophysiological parameters, fungal alkaloid production, and forage quality. Results from this project will further our understanding of how forage production and quality of pastures of the upper transition zone are likely to respond to predicted future changes in climate. Data will inform forage breeders about the ability of various forage species and fescue genotypes to adapt to and withstand warmer and potentially wetter conditions. The exploration of genotype effects and interactions with climate on the tall fescue-fungal endophyte symbiosis and secondary metabolite production will generate novel information of potential interest to a broad array of scientists (i.e., agronomists and animal scientists, ecologists, fungal biologists, plant physiologists and molecular biologists) and may also have direct management implications, given the significant effect of alkaloids on animal production on fescue-based grassland systems.