PARENT SESSION
Oral Session # 61: Biogeochemistry IV: Al, Ca, P, and DOC.
Presiding: R Fitzhugh
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 205.

Ecological stoichiometric differences on islands in the Gulf of California.

Huxel, Gary^*,1, Talley, Drew^{1, 2}, Sanchez-Pinero, Francisco³, ¹ University of South Florida, Tampa, FL² University of California, Davis, Davis, CA³ Universidad de Granada, Granada, Andalucia, Spain

ABSTRACT- Our previous research has demonstrated significant differences among tenebrionid beetles on islands in the Gulf of California. The islands vary is use by seabirds and are classified as non-bird, roosting, and nesting islands. On roosting and nesting islands, seabird carcasses are the primary carbon sources, while on non-seabird islands plant detritus is the major resource of carbon for the beetles. However, significant differences in nitrogen and phosphorus concentrations between plant and carrion tissues, and within and across island types exist. We address whether these differences influence patterns of resource flow. We find that on non-bird islands while C comes mostly from plant tissue, C contributes the vast majority of nitrogen and phosphorus. On nesting islands, C, N, and P are all mostly derived from carrion resources. However, on roosting islands because plant tissue reaches its highest density, and N and P concentrations are the highest in plants, C, N, and P are derived nearly equally from plant and carrion tissues. These differences in stoichiometry have significant influences on the diversity of tenebrionid beetles (both alpha and beta diversities) on islands in the Gulf of California.

Key words: nitrogen, tenebrionid beetles, stoichiometry, phosphorus