Climate variability is a key challenge for range management, as forage can fluctuate widely with rainfall. At the same time, climate variation may promote coexistence of different forage species. Importantly, recent work suggests that previous-year rainfall is as important as current-year rainfall for rangeland dynamics. This study of lagged effects of precipitation on rangelands focuses on interactions between the common annual forage grass, nonnative Avena barbata, and the native perennial bunchgrass, Stipa pulchra.

This project combines a manipulative experiment with demographic modeling to (1) investigate the differences in lagged drought responses of nonnative annual versus native perennial grasses (2) understand the role of lagged rainfall effects for maintaining annual-perennial coexistence in California rangelands, (3) investigate the consequences of lagged rainfall effects on stability of grassland productivity. 

Using the large-scale climate shelters at Sierra Foothills Research and Extension Center, we measure life history traits and competition between Stipa and Avena planted in different abundances.