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Harvard Forest Symposium Abstract 2011

  • Title: Effects of climate change on ecology of ground-dwelling spiders
  • Primary Author: Irma Nieto (University of Vermont (UVM))
  • Additional Authors: Nicholas Gotelli (University of Vermont (UVM))
  • Abstract:

    Climate change is altering biodiversity through changes in population and community-level processes. Some species are contracting from the equatorial and extending beyond the poleward edges of their ranges. Variation in the capacity for and rate of this process across species can lead to changes in community composition, ultimately affecting ecosystem function and services. Scientists have been using models to project changes in species’ distributions, but these models often oversimplify processes limiting species’ ranges. Therefore, experimental field manipulations that directly test the effects of warming on populations and communities are needed to better understand the effects of climate change on biodiversity. Here use large open-top environmental heating chambers to simultaneously manipulate temperature from ambient to 6°C above ambient, using a statistically powerful and cost-efficient response-surface (regression) design at two field sites situated in northern and southern temperate mixed hardwood forests in eastern North America (Harvard Forest in Massachusetts, Duke Forest in North Carolina). The proposed field manipulations will reveal the effects of temperature increases on the populations, communities of assemblages of ground spiders. Spiders are a model taxon for studying effects of global climatic change because they comprise the dominant fraction of animal biomass in many terrestrial communities and because they are generalist predators. Over three years, the species composition and phenology will be monitored. The experiment tests the predictions that, under climate change, spider abundance will increase in the north and decrease in the south and spider biodiversity will decline.

    A total of 689 spiders were collected during this study, and 424 were mature corresponding to 31 species (Table1). The regression models indicate that the spider abundance of three species have a significant relationship with temperature, within the July 2009, March, April, July and August 2010 (Table2, Figure1). But when we modeling the total spider abundance (adults + immatures) as a function of the temperature, we found significant relationship in July 2009 and from May to Augusto 2010 (Table3, Figure 2).

  • Research Category: Biodiversity Studies

  • Figures:
  • Table 1.pdf
    Table 2_Fig 1.pdf
    Table 3_Fig 2.pdf