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Harvard Forest REU Symposium Abstract 2016

• Title: Community composition of woody species at their range limits in eastern North America
• Author: Alice H Linder (Harvard University)
• Abstract:

  Plant species’ ranges are determined through biotic and abiotic factors such as competition and stressful environments. Tree species in broadleaf temperate forests in the Northeast face changes to these ecological limitations due to shifting temperatures across their range. The effect of this shift is predicted to be most apparent at the species’ range limits, where such a change in conditions that previously halted population expansion can cause a range shift. By examining species at their range limits, we can predict their future responses to climate change and the implications for their distribution and success. The goal of this study was to determine how species richness and composition of competitive neighborhoods change across a latitudinal gradient in the Northeast. We examined whether focal deciduous tree species face a competitive disadvantage at their range extremes, which will in turn provide insight into how the species will respond to changing temperatures. We recorded the size and community composition of seven deciduous tree species at their range limits, varying from the northeastern United States to southeastern Quebec. Higher relative basal area, as well as taller individuals, indicates a competitive advantage. Results show a trend towards lower competitive ability for Betula papyrifera at its southern range extreme at Harvard Forest. For the other five species we examined, we saw very little change across the gradient. We also analyzed understory and over-story composition and plant functional traits.

• Research Category: Regional Studies; Physiological Ecology, Population Dynamics, and Species Interactions; Group Projects; Biodiversity Studies