PARENT SESSION
Poster Session 37: Forest Ecology.
Thursday, August 5 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Using dendrochronology to reconstruct the effects of climate and host condition on a wood boring insect.
MUZIKA, R*,1, GUYETTE, R1, 1 University of Missouri-Columbia, Columbia, MO, USA
ABSTRACT- Long-term time series data are critical for understanding endemic and epidemic populations of insects, their temporal and spatial dynamics, and factors affecting outbreaks. We constructed multi-decadal records of red oak borer (Enaphalodes rufulus (Haldeman) Coleoptera: Cerambycidae) using dendrochronologically dated tree wounds caused by the insect, and examined the long-term response of red oak borer populations to climate, host age and growth rate. The methods provide wounding dates with annual resolution and absolute spatial location, so that this approach can be used to determine biotic and abiotic bottom up factors, and their relevant temporal and spatial scales. In an oak (Quercus) dominated forest in Missouri, over 700 borer wounds were tree-ring dated on 31 trees (Q. coccinea and Q. velutina) that were sectioned at 1 m height intervals. We determined that red oak borer wounds, precisely dated by dendrochronological methods, can be used to document the timing and magnitude of larval activity. Overall borer activity in this even-aged forest has increased over the past 70 years, particularly in the most recent 25 years. Borer activity increased with tree age and mean growing season temperature, but was not significantly related to precipitation or to basal area increment. Greater insect activity was associated with decreases in wood density. Models are used to identify vulnerable trees and stands, and to evaluate the importance of factors such as climate, management history, and site conditions. This research contributes to development of a precise climate response function and to a greater understanding of the influence of climate change on insects, particularly potential pest species.
Key words: beetle, dendrochronology, Quercus, insect populations