Research

A number of different projects are being conducted in the lab.  My students typically undertake related, but non-overlapping projects with my main projects, but we all work as a team to improve and refine each project. See people pages for all of these projects.

I have three main projects going in the lab currently.

I. Using historical and contemporary approaches to reconstruct pathways to ecological specialization.  Ecological specialists comprise a large portion of global biodiversity. In this project, undertaken with post-doc N. Ivalu Cacho, we are working to understand the evolution of soil specialization in, and the evolutionary relationships among, members of the Streptanthoid complex, a diverse group of mustards, many endemic to the California Floristic Province. We have generated a phylogenetic hypothesis for the group (in review Molecular Evolution and Phylogenetics) and are using this hypothesis to understand trade-offs associated with soil specialization, specifically serpentine endemism. We use current ecological competition experiments in field soils, field and trait surveys and the phylogeny to understand the selective pressures and trade-offs, including both biotic and abiotic forces, leading to edaphic specialization. Our field sites span  Southern CA to Oregon, from deserts to high mountains, coastal areas and inland. Streptanthus and allies are called ‘jewelflowers’ and I  think they are super cool and beautiful. This helps keep me going when I am struggling in their preferred habitat of hot, south-facing very loose, steep and rocky slopes.

II.   Community phylogenetics and niche conservatism in plant communities.  With Jean Burns and Brian Anacker, I am studying plant community assembly at the UC Bodega Marine Reserve. We use experimental approaches, planting individuals into the niches of more and less closely related species, to understand niche conservatism and coexistence among species. We are also measuring many traits and environmental attributes across our site to understand the major contributors to coexistence in this diverse community.

III. Understanding the role of rhizobia and soil communities in coexistence of diverse Trifolium species assemblages. At the Bodega Marine Reserve, there are 9 native species of Trifolium, and many introduced ones. In collaboration with Maren Friesen at MSU, I will be starting a large project in which we use transcriptomics of Trifolium species planted across soil niches, in the presence and absence of the local competitor, as well as rhizobial sequencing and rhizobia-species affinity/interactions to understand competitive/mutualistic interactions and  N-fixation efficiency.