Harvard Forest Research

Succession of Predatory Arthropod Diversity (Spiders and Ground Beetles) in Newly Harvested Pine Plantations

Principal Investigator: Aaron Ellison
Harvard Forest: May 15 2008 - Oct 01 2010:

Abstract:
Between 1911 and 1944, several large spruce and pine plantations were established at the Harvard Forest, of which 135 total acres remained in fall 2007. Recent studies show that plantations have 20 to 30% less vegetative species richness than native forests. Because arthropod species richness is closely linked to a habitat’s vegetative structure, I hypothesize that arthropod richness is similarly lower in plantations than in native forests. In fall 2007, I established nine 25-square-meter plots (6 plots to be harvested in 2008, 3 to remain unharvested), with a four-week arthropod collection cycle, to establish a baseline of species richness in the plantations. The same collection cycle will be repeated in the spring/fall 2008, again in spring/fall 2009, and possibly in spring/fall 2010, tracking the successional richness of the predatory arthropods as they recolonize the harvested plantation areas. Just after the plantations are harvested, I project that predatory arthropod richness will drastically decrease, because only a small number of spiders and ground beetles are known to colonize disturbed areas. As the harvested plantations gradually return to native forest, I predict that arthropod species richness will not only increase, but increase well beyond the baseline established from the plantation state. This study has implications for several correlated research trajectories: successional richness of spiders and ground beetles in disturbed areas has only recently appeared in the literature; around the world, plantation seeding and harvesting continues as a common management practice, alongside uncoordinated efforts to manage animal species; spiders and ground beetles are uniquely situated as both predator and prey for a wide array of animals of ecological concern.: