Hastings Natural History Reservation

17 Apr, 05 AM - 17 Apr, 08 AM

Project Overview: This project addresses how coevolutionary dynamics are structured across complex geographic landscapes and lineages. I am interested in how one on one interactions change as they become embedded within different communities of other taxa. The Lithophragma (Saxifragaceae) and Greya (Prodoxidae) interactions have been studied extensively in a one on one framework and provide a unique system in which to take the next step to coevolutionary dynamics in a multispecific setting. Two species of Lithophragma, L. affine and L. heterophyllum, co-occur along the California coast ranges and are obligately used by G. politella (pollinating seed parasite) and G. obscura (oviposits through the side of the ovary). This four species interaction provides a unique system in which to study the diversification of interactions within a clade. The two major objectives of this study will be: 1. Determine the interaction structure of both L. affine and L. heterophyllum with G. obscura and G. politella. 2. Determine the phylogeography of all species involved and how that corresponds to the interaction structure. These objectives will be addressed using a combination of ecological observations and phylogenetic analyses across the Lithophragma range. Plant and insect material will be collected for molecular work and voucher specimens. Plant and insect material collections will be maintained in the laboratory of John Thompson, UC Santa Cruz. Proposed Collection Methods, Spring 2002 In Spring 2002, one population of L. affine and one population of L. heterophyllum were found in the Hastings Natural History Reserve. The L. affine population is located on the hillside adjacent to the main entrance road, near the tree line. The L. heterophyllum population is along the entire main roadside, growing on the shady road cut. Two cauline or rosette leaves will be removed from about 20 individuals in each population and placed on drierite for later DNA extraction. Individuals that appear to be setting seed will be marked at the base with flagging and revisited at weekly intervals to collect seed. Flagging will be removed as individuals set seed. Greenhouse experiments are planned in Spring 2003 using the collected seed. Other field sites of mine have not set an abundant number of seeds and I have had to supplement my seed collection with bulbils. L. heterophyllum produces aerial bulbils at the nodes of cauline leaves and these can be collected without harm to the plant. One plant can produce 10-100 bulbils, depending on site. Bulbils from about 10 L. heterophyllum individuals may be collected if sufficient seed is not collected. L. affine produces only subterranean bulbils and the entire plant must be dug up to collect these. If L. affine fails to set sufficient seed, I will dig up 4-5 L. affine to collect bulbils. Future greenhouse and field experiments require that I grow 50-75 individuals from each site, so adequate seed and bulbil supply is imperative.

Visit #390 @Hastings Natural History Reservation

Approved

Under Project # 389 | Research

University of California, Santa Cruz - Ecology and Evolutionary Biology

graduate_student - University of California, Santa Cruz

Reservation Members(s)

Katherine Horjus Apr 17, 2002 (1 days)

Reserve Resources(s) | Create Invoice

Day Use Only 1 Apr 17 (3 hours)