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Harvard Forest REU Symposium Abstract 2005
- Title: Changes in Herbaceous Vegetation Composition in Response to Soil Warming
- Author: Katherine J Lenoir (Wellesley College)
- Abstract:
This project studied the effects of warmed soils on herbaceous vegetation and Acer rubrum seedling growth at Barre Woods, in July 2005. Percent sunlight to plots was also compared to plant density and diversity (Shannon’s and Margalef’s indices). Herbaceous composition was studied (including graminoids, lycopodium, and ferns) by stem counts of all species present in randomly selected circle (3.14m2 area) and square plots (1m2 area) of experimentally heated and control megaplots (900 m2). Herbaceous species composition of square plots was also sampled in 2002, before heating began, allowing for comparison of square plots in 2005 with pretreatment. Heated plots had cables running through the soil, to increase the temperature by 5ºC; heating has been turned on since 2003. Light data was measured per plot by taking hemispherical photographs, which were then analyzed with Hemiview software for percentage of sunlight in sampled plots. Acer rubrum seedlings were collected from heated and control megaplots and planted in a green house, in order to count number of germinating seedlings and growth rate of seedlings. There was no difference in herbaceous diversity between heated and control plots, however, the composition of species changed from 2002 to 2005. Maianthemum canadense density increased significantly, while Lycopodium obscurum density decreased significantly in the heated plot. The percent of light coverage in the forest did not correlate to diversity or density of herbaceous plants. Acer rubrum seedlings from the control plot were heavier and germinated more often.
- Research Category:
