PS 59-45 - Relationships among understory vegetation, insect diversity, and forest management in hemlock-dominated ecosystems

Thursday, August 11, 2011
Exhibit Hall 3, Austin Convention Center
Alysa J. Remsburg1, Erika F. Latty2, Amy Arnett2 and Kathleen Dunckel3, (1)Unity College, Unity, ME, (2)Center for Biodiversity, Unity College, Unity, ME, (3)Center for Natural Resource Management and Protection, Unity College, Unity, ME

Understanding the impact of logging practices on ecosystem function is extremely important, particularly in the face of salvage logging in pest-infested forests. In this study, we are investigating the impact of logging in hemlock-dominated forests in central Maine. The Hemlock Woolly Adelgid (HWA) is currently killing eastern hemlock (Tsuga canadensis) in southern Maine within 80 miles of the study area. This study is designed to understand the community shifts, and associated change in ecosystem processes, that will occur with preemptive logging in the face of potential loss of hemlock to HWA. To do this, we recorded baseline community and ecosystem data for hemlock-dominated forests in central Maine, where hemlock-dominated have not been well described. We measured several ecological variables in 59 plots each 100 m2 in area; 25 of the plots were logged for hemlock within the last two years.  We recorded community composition of ants and carabid beetles, understory vegetation patterns, leaf litter composition, fine and coarse woody debris abundances, soil moisture, and photosynthetically active radiation (PAR).   


Our results suggest that logging influenced leaf litter composition: bark and fine woody debris biomasses were greater at the logged plots, while deciduous litter was higher at the unlogged plots. The stem density of the woody seedlings was highest in the logged plots but stem densities of ferns and herbaceous plants were similar between treatments. We also found that community composition of carabid beetles and ants differed between logged and unlogged plots. The shift in ant communities from Formica dominated to Aphaenogaster dominated in logged plots suggests a change in the efficiency of ecosystem processes.  An understanding of how logging alters ecosystem processes and community diversity will help inform forest management practices in the face of HWA infestation. 

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