UC Berkeley

The spatial distribution and species composition of plant communities depend on a multitude of potentially interacting drivers. These drivers include abiotic factors, such as climate conditions, and biotic factors, such as species interactions. Long-term data on vital rates (i.e., survival, growth, reproduction) for individuals in a community can reveal the influence of factors such as climate and neighboring individuals on performance. In this dissertation, I use a demography dataset that tracks the location and vital rates of over 3,300 individuals of 18 species across nine years in an alpine plant community. Here, I test whether vital rates respond to microenvironment modification of ground temperatures and soil moisture by neighboring plants. In the next chapter, I assess how abiotic dispersal may promote the co-location of seeds and host plants and, thus, influence species interactions. Finally, I explore how species respond to increased vital rate variance from environmental stochasticity by estimating the extent that population stochastic growth rates are buffered to perturbations. Collectively, this dissertation demonstrates the sensitivity of demographic processes to macroclimate, seed dispersal, and environmental stochasticity within and across co-occurring species using a highly resolved model system.