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Harvard Forest REU Symposium Abstract 2018

  • Title: What does the future hold for the Harvard Forest Megaplot? Seedling Abundance, Diversity, and Mortality
  • Author: Nia J Riggins (Bryn Mawr College)
  • Abstract:

    Forests are important because they benefit the economy, harbor biodiversity, store carbon, and are a valuable conservation mechanism. Unfortunately several trees are dying due to the invasive species such as Tsuga canadensis (eastern hemlock) being killed by the Adelges tsugae (hemlock wooly adelgid). Tsuga canadensis is a hypothesized foundation species that is prevalent in the eastern United States. This tree casts deep shade over the area it occupies. For this reason, T.canadensis has a big effect on understory plant abundance, diversity, and mortality because light limitation can affect how plants grow and survive. How will the absence of this T. canadensis affect seedling recruitment in the forest. To answer this question data was collected from the hemlock-dominated mega plot where adelgid was first found in 2009. Seedlings that reside in meter by meter plots were measured and identified, and hemispherical canopy pictures were taken to measure canopy openness. A total of 4,240 seedlings were measured with the top species found being Acer rubrum (red maple) at 2,557 seedlings and T.canadensis at 604 seedlings. Abundance changes as the amount of light available to the seedlings changes. The overall survivorship rate for the seedlings was 0.863 and mortality rate was 0.1587. It is necessary to study seedlings because they represent the future trees.

  • Research Category: Group Projects; Large Experiments and Permanent Plot Studies; Physiological Ecology, Population Dynamics, and Species Interactions