UC Santa Barbara

Foundation species are species that tend to dominate the biomass of a community, modify the physical environment, and shape the habitat in which other species exist. Global change threatens ecosystems in which foundation species play a major role, in large part because the loss of foundation species may cause major shifts in community structure. Giant kelp (Macrocystis pyrifera) is a foundation species that shapes Santa Barbara’s subtidal marine ecosystems. Giant kelp grows from the seafloor to the surface, creating a densely vegetated canopy that supports a rich benthic community of invertebrates and macroalgae. In this dissertation, I leverage giant kelp as a fitting study system to examine the consequences of foundation species loss and recovery, and ask how species characteristics (i.e. functional traits) define species differentiation within a kelp forest. I work with observational community data and experimental manipulation from the Santa Barbara Coastal Long-Term Ecological Research (SBC LTER) program, and field-collected functional trait data from SBC LTER sites. In my work, I demonstrate that 1) foundation species loss and recovery ultimately influences community structure, 2) foundation species influence community biomass directly and indirectly via community diversity, and 3) functional traits reveal species similarities and groupings that are not reflected by traditional functional forms.