Research

Drought impacts on post-fire regeneration

I study how pre- and post-fire drought impacts regeneration of plant communities after fire. My work spans experimental snowpack manipulations and large-scale observational datasets of natural regeneration to understand the balance of direct effects of drought with indirect effects via species interactions. Past study sites include Sierra Nevada mixed conifer forest and northern California serpentine chaparral.

Lagged effects of drought in California grasslands

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. This study uses the large-scale climate shelters at Sierra Foothills Research and Extension Center, to understand drought impacts 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. 

Drivers of restoration success in mountain meadows

Working with Scott River Watershed Council, we are investigating potential factors benefiting and hampering restoration of mountain meadows. This project examines the potential of seed banks—species present in an area as seeds but not common above-ground as plants—to promote natural regeneration of meadow communities after restoration of hydrologic processes. We also study the impact of early- versus late-season cattle grazing on the meadow restoration

Modeling coexistence in diverse communities

I develop complex models to better understand patterns of coexistence between species, and extend ecological coexistence theories to natural and managed systems. My work includes the development of a Bayesian sparse modeling approach to quantifying species interactions in diverse communities, extending coexistence models to mixed annual- and perennial-dominated communities, and examining how patterns of temporal and spatial heterogeneity differ between annual- and perennial-dominated communities.

My collaborative approach to building ecological theory includes participation in two international synthesis workshops, sPriority: Mechanisms and quantification of priority effects, and sToration.