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Harvard Forest Symposium Abstract 2009

  • Title: How are ground-dwelling micro-arthropod communities and nutrient flow affected by the loss of hemlock?
  • Primary Author: Tara Sackett (University of Toronto)
  • Additional Authors: Aimee Classen (University of Tennessee at Knoxville); Aaron Ellison (Independent); Nicholas Gotelli (University of Vermont (UVM)); Nick Reynolds (University of Tennessee at Knoxville); Nathan Sanders (University of Tennessee at Knoxville)
  • Abstract:

    Litter-dwelling arthropod communities in hemlock stands infested by the Hemlock Woolly Adelgid (Adelges tsugae) may shift in composition as deciduous species become more predominant in the canopy and litter. These changes may also affect associated ecosystem functions. In this experiment we are testing for changes in microarthropod communities and nutrient flow as a result of a shift in litter composition from hemlock to deciduous.

    Our experiment uses 0.5 x 0.5 m blocks of litter (“litter loaves”) as sample units; these loaves were removed from the ground just above the mineral horizon, so that the litter strata of the loaf remain intact. At Harvard Forest in October 2007 we switched litter loaves between hemlock and deciduous stands, as well as maintaining control plots (within stand switches) and undisturbed controls in each stand type (6 treatments). There were 6 sample units per treatment, and we replicated the experiment in two pairs of stands. Beginning in November 2007 ion-exchange resin bags (15 mL resin) were placed under each litter loaf and control plot and replaced every 6 months.

    We will leave the litter plots for 1.5 years. The resin bags will analyzed for changes in nutrient flow. In the spring of 2009 we will destructively sample the plots to census arthropods.

  • Research Category: Biodiversity Studies