An experimental ‘null model’ in California serpentine meadows (current): Environmental conditions scale with distance, making it difficult to assess the individual effects of environment or distance in explaining spatial patterns of species diversity. Experiments designed to circumvent this problem, by using seed addition experiments or constructing artificial communities, recreate species pools in ways that poorly represent spatial structure in natural communities. At the McLaughlin Natural Reserve in Northern California, I vacuumed all seed material from plots located across the 2800-ha reserve, created species pools that contained species found at multiple spatial scales (e.g., plots 1 meter to 5 miles apart), and reintroduced these seed mixes back onto the plots. This method effectively removed the effect of distance, and will allow me to evaluate the role of environment alone in structuring annual plant communities in this system. Project with Sharon Strauss and Ben Gilbert.
Belowground rhizotron experiment (current): 30 species of annual plants were grown in clear tubes and tilted on a 45-degree angle. Roots grow gravitropically against the surface of the clear tube, which allows me to non-destructively observe belowground root architecture traits over time. These belowground traits are important for the ecological dynamics of annual plants, particularly for species that experience frequent water limitation in their Mediterranean climates. However, this traits are often overlooked because they are logistically intractable to measure–until now! Project with Chris Blackford and Ben Gilbert.
Maternal effects in ecological communities (2013) — see the paper here: We grew 30 species of annual plants in wet or dry environments, and looked at how the success of offspring differed depending on the maternal environment. We found that 40% of species demonstrate significant maternal effects in seed size, seed dormancy, or offspring performance, which is pretty cool since this is the first study to quantify maternal effects across a range of species. Project with Ben Gilbert.
Small mammal effects on community assembly (2011) — see the paper here: Small mammals are voracious plant predators, but are also primary prey for many aerial hunters. To avoid predators, small mammals often restrict their activity to areas perceived as low risk. In a restored tallgrass prairie in Ontario, we found that small mammal activity decreased with distance from adjacent old-field habitat that is high in plant cover. Because small mammals preferentially predate on a subset of available plant species in prairies, we found that beta-diversity was high in areas far from old-field where small mammals were less abundant, allowing plant community assembly to unfold stochastically regardless of seed palatability. Project with Laura Johnson and Andrew MacDougall.