PARENT SESSION
Oral Session #105: Conservation Ecology: Biodiversity.
Presiding: L. Alonso
Friday, August 9. 9:00 AM to 12:00 PM. Grand Ballroom Central, Radisson.

Does oak herbivore species richness show clear-cut responses to timber harvest in Missouri Ozark Forests?

Forkner, Rebecca^*,1, Marquis, Robert¹, Lill, John², Le Corff, Josianne³, ¹ University of Missouri-St. Louis, St. Louis, MO² Tyson Research Center, Eureka, MO³ Institut National d'Horticulture, Angiers, France

ABSTRACT- We report the impacts of uneven-aged (UAM, i.e. selectively logged) and even-aged (EAM, i.e. clear-cut) timber management regimes on the species richness of leaf-chewing herbivores of Quercus alba and Quercus velutina (white oak and black oak, respectively) in the Missouri Ozarks. This is the first study to examine the effects of logging on insects during the life stage that damages leaves. We censused leaf-chewing herbivores feeding in intact understory and canopy forest stands within replicates of each timber harvest practice and no-harvest controls (NHM) for 3 years prior to and 5 years after timber extraction. Pre-treatment data showed no differences in species richness among stands in UAM, EAM, or NHM canopy or understory sites. The density of species (#/m² leaf area) of Q. velutina herbivores in understory UAM sites was reduced relative to EAM and NHM sites in post-harvest years. Rarefaction curves for UAM and EAM canopy and understory sites in post-harvest years fell within the 95% confidence intervals for NHM rarefaction curves. Prior management history also affected herbivore richness: richness increased with increasing time since last disturbance (e.g., logging, fire, or grazing). These results suggest that this low level of timber extraction does not drastically alter species richness, but more severe cutting would do so.

KEY WORDS: logging, Quercus spp., Lepidoptera