You are here

Harvard Forest >

Harvard Forest REU Symposium Abstract 2011

  • Title: Warming Effects on Ants Soil Movement and Mortality Rates
  • Author: Natashia Manyak (University of Massachusetts - Amherst )
  • Abstract:

    Ants are important components of most terrestrial ecosystems since they are often associated with key processes like soil movement. Specifically, ants that build subterranean nests have an effect on soil nutrient dynamics due to the large amount of soil that are displaced during nest excavation. Our study focuses on the effects of warming on a common ant of the forests of the Northeastern U.S, Formica subsericea. My objective was to determine if the rate of soil movement and total mortality varies under different warming treatments .We hypothesized that under warmer treatments, ant soil movement may peak at a temperature under which ants can work most efficiently and still survive, but beyond which their activity may be detrimentally affected. We also hypothesized that under warmer treatments ant mortality rate will increase as a consequence of metabolic exhaustion. We tested these hypotheses in a microcosm warming experiment using two warming treatments (+3°C and +5°C) and a controlled, non-manipulated treatment. One hundred individual ants were kept in 90, 19 liter containers and left to build nests for a period of four weeks. Rate of soil displaced was determined through time series photographs taken at 12 hour intervals for a duration of 120 hours. We analyzed the resulting images using ImageJ freeware. Mortality rate was measured weekly by counting number of dead ants per colony at all 90 microcosms. We found that ant mortality rate was not significantly different across the temperature treatments and was directly linked to rate of soil excavation. Further analysis is required to evaluate the variation in excavation rates between warming treatments. This study provides an analysis of how predicted regional warming may affect ant soil movement dynamics.

  • Research Category: Physiological Ecology, Population Dynamics, and Species Interactions; Soil Carbon and Nitrogen Dynamics