Who’s Bugging Out?: The Impacts of Mechanical Thinning on Arthropod Communities in
Northern Arizona, USA
Jerod Benefield1, Dr. Karen Haubensak2, Dr. Richard Hofstetter3
UGRAD Symposium Abstract, 2013
Mechanical thinning is a widely used forest management tool in the southwestern United
States. Decreasing stand densities, or the number of trees per acre, are known to increase
understory production in terms of both vegetation abundance and richness. The effects of these
post-thinning condition changes on macroarthropod communities within soil and litter food webs
are not currently known. My goal is to quantify insect community responses to the understory
vegetation changes induced by mechanical thinning treatments. Stand characteristics and pit trap
samples were collected from 16 sites (8 mechanically thinned, 8 unmanaged) during the premonsoon month of June and the post-monsoon month of September during 2012. Samples were
analyzed in the lab and arthropod specimens were categorized according to functional guilds.
Based on cascading trophic level responses to changes in understory vegetation within thinned
sites, we expect to observe distinct differences within macroarthropod community assemblages
between mechanically thinned and unmanaged sites. As drivers of nutrient cycling and
decomposition within forest ecosystems, arthropod communities and their responses to habitat
manipulation should be studied to ensure responsible forest management and better understand
landscape level changes from forest thinning.
Northern Arizona University1, 2, 3, School of Forestry1, 3, Department of Biological Sciences2