public read Forest Ecosystem Monitoring Cooperative

705 Spear StreetSouth BurlingtonVermont05403United States of America

(802) 656-0683femc@uvm.eduwww.uvm.edu/femcHarvard University Harvard ForestleadDuke Forest partnerThroughout the Northeast, the hemlock woolly adelgid (Adelges tsugae) threatens eastern hemlock (Tsuga canadensis) through direct mortality resulting from infestation followed by defoliation and indirect mortality in the form of pre-emptive logging. The efficacy of regeneration of vegetation following hemlock decline depends upon advance regeneration of seedlings and saplings, seed dispersal, and recruitment. This study investigated (1) whether the basic parameters of height of release and wind velocity affected seed dispersal distance and (2) the fit of a basic ballistic model of seed dispersal to empirical data in areas both with and without canopies. Empirical data was collected from seed dropping and seed rain experiments at Harvard Forest. Height and wind velocity only affected seed dispersal distance in open areas. Predicted values of dispersal distance generated by the basic ballistic model did not provide a good fit to observed dispersal data. Poor fits of the ballistic model to the data were due to the model’s inability to account for rare, long distance dispersal events. More complex models with additional parameters are necessary to model Non-localized seed dispersal. Forest Ecosystem Monitoring CooperativeEmeryBooseprincipalInvestigatorSince 1907, the Harvard Forest has served as a center for research and education in forest biology and conservation. The Forest's Long Term Ecological Research (LTER) program, established in 1988 and funded by the National Science Foundation, provides a framework for much of this activity.Tree Seed Dispersal in Hemlock Removal Experiment at Harvard Forest 2005Throughout the Northeast, the hemlock woolly adelgid (Adelges tsugae) threatens eastern hemlock (Tsuga canadensis) through direct mortality resulting from infestation followed by defoliation and indirect mortality in the form of pre-emptive logging. The efficacy of regeneration of vegetation following hemlock decline depends upon advance regeneration of seedlings and saplings, seed dispersal, and recruitment. This study investigated (1) whether the basic parameters of height of release and wind velocity affected seed dispersal distance and (2) the fit of a basic ballistic model of seed dispersal to empirical data in areas both with and without canopies. Empirical data was collected from seed dropping and seed rain experiments at Harvard Forest. Height and wind velocity only affected seed dispersal distance in open areas. Predicted values of dispersal distance generated by the basic ballistic model did not provide a good fit to observed dispersal data. Poor fits of the ballistic model to the data were due to the model’s inability to account for rare, long distance dispersal events. More complex models with additional parameters are necessary to model Non-localized seed dispersal. VMC.1387.2861mySQL/femc/data/archive/project/Harvard_Forest_Research/dataset/tree-seed-dispersal-hemlock-removal-experiment2005-01-012005-12-31speciesSpecies in Tree Seed Dispersal in Hemlock Removal Exp at HF datasetSpecies in Tree Seed Dispersal in Hemlock Removal Exp at HF 2005 dataset (hf120)textAcer sp.ITIS #28727, maples (Acer sp.)Quercus sp.ITIS #19276, oak (Quercus sp.)Betula sp.ITIS #19478, birch (Betula sp.)Tsuga canadensisITIS #183397, Canada hemlock; hemlock spruce (Tsuga canadensis)