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Harvard Forest Symposium Abstract 2015

  • Title: Biogeographic variation in the potential for scatter hoarders to act as mutualists for three tree species
  • Primary Author: Michael Steele (Wilkes University)
  • Additional Authors: Harmony Dalgleish (William and Mary College)
  • Abstract:

    We use a model developed by Zwolak and Crone (2011) to address two sets of questions related to the dispersal and establishment of oaks and American chestnut: (1) how does the potential for scatter hoarders (primarily rodents) to act as mutualists vary across two oak species (Quercus rubra [RO]and Q. alba [WO]) and American chestnut (Castanea dentata)? And, (2) what is the influence of seed source and temperature on this potential? In this artificial cache experiment we will use a system of 15 enclosures (1350 nuts) per site across 5-6 geographically diverse sites (one of which is Harvard Forest). By enclosing seeds and preventing access by seed consumers, we plan to determine the probability of seed emergence for artificially cached and non-cached nuts of the three tree species. From previous studies we already have reasonable estimates on the probability of each of these seed types to be cached and not recovered (also needed in the Zwolak-Crone Model). The multi-year study (probably 2 years) will involve testing RO and WO acorns from Virginia across all sites, and RO and WO acorns from each site in Virginia. Nuts of American chestnut (AC) will be acquired from the American Chestnut Foundation. Pure AC nuts will be used when available but in 2012-2013 we will use BC3F2 seed, estimated to be about 15/16 of pure AC. Enclosures (containing nuts) will be placed in the field in early November and germination and establishment success will be determined in the spring. We will monitor temperature with iButtons and monitor soil moisture with soil moisture sensors and data loggers (3-5 sensors and 1 logger per site). Harvard Forest is selected as one of the 6 potential sites (others in PA, VA, ME, IN, and MD) we plan to use in this study. HF is chosen because of its security, proximity to the other sites in the study, and its forest composition (oak dominance).

  • Research Category: Biodiversity Studies