PARENT SESSION
Oral Session #83: Insect Population and Community Ecology.
Presiding: C. Rodriguez-Saona
Thursday, August 8. 9:00 AM to 11:30 AM. Palo Verde Room, Radisson.

Host plant genetics affects arthropod community composition.

WIMP, GINA^*,1, MARTINSEN, GREGORY¹, YOUNG, WILLIAM¹, WHITHAM, THOMAS¹, ¹ Northern Arizona University, Flagstaff, Arizona

ABSTRACT- We sought to examine how host plant hybridization (Populus angustifolia x P. fremontii) affected arthropod diversity, abundance, and composition on cottonwoods. Previous observational studies showed that different communities were found associated with the different cross types and their parental species (Fremont, F₁ and backcross hybrids, and narrowleaf). In order to experimentally examine the relationship between host plant hybridization and arthropod community structure, we utilized a 10 year-old common garden of the different tree types where pure or hybrid status was established using molecular techniques. Although we did not find differences in arthropod species richness and abundance across tree types, we did find significant differences in community composition. All tree types except backcross hybrids and narrowleaf were significantly different from one another in arthropod community composition. Using vector analysis, we found that percent Fremont alleles in individual trees could be used to accurately predict the shift in community composition. These patterns were repeated over two years of study. At the stand level, the greatest variation in tree genotypes resulted in the greatest arthropod species diversity. These results have implications for riparian restoration ecology because conservation of genetic diversity in producers can enhance biodiversity in other trophic levels.

KEY WORDS: community, genetics