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Harvard Forest Symposium Abstract 2008

  • Title: Climate Change Baselines: The Rate of Floral Change in an Ordinary Forest in an Ordinary Century
  • Primary Author: Jerry Jenkins (Wildlife Conservation Society)
  • Additional Authors: Glenn Motzkin (University of Massachusetts - Amherst )
  • Abstract:

    To assess the response of plant communities to climate change, we need background measurements of the rate of floral change under relatively constant climates in the past. We report one such measurement here. The Harvard Forest is an 1,100 hectare tract of upland forests and wetlands in central Massachusetts. It has been owned by Harvard University for 101 years, and was first used as a forest experiment station and then as a NSF Long-term Ecological Reserve. In this period it has lost pastures, gained forests, passed through a period of intensive silviculture and a major hurricane, and been subject to acid deposition and some climate amelioration. But it has not seen major alterations in the land use of the forest or the surrounding watersheds. The botanical record consists of 3,600 herbarium specimens and 808 verified species, compiled in three checklists and one full flora. We conducted a four-year inventory of the flora and analyzed historical changes using six metrics. We found that the taxonomic and life-form spectra, species richness of characteristic habitats, and level of geographic specialization of the native flora have changed little despite the loss of open lands, the aging of the forests, and a significant (~15%) turnover in species composition; we suggest that these may be robust metrics against which to measure future change. The alien flora, on the other hand, showed distinct richness and compositional changes, and we suggest that it may need to be excluded from future analyses of change.

  • Research Category: Biodiversity Studies, Historical and Retrospective Studies, Physiological Ecology, Population Dynamics, and Species Interactions