Using Structural and Thermal Heterogeneity To Minimize or Reverse the Impacts of Climate Change in Terrestrial Systems

EPA Grant Number: FP917237
Title: Using Structural and Thermal Heterogeneity To Minimize or Reverse the Impacts of Climate Change in Terrestrial Systems
Investigators: Schuler, Matthew Scott
Institution: Washington University
EPA Project Officer: Jones, Brandon
Project Period: September 1, 2010 through August 31, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Global Change


Current forest management techniques have reduced structural heterogeneity at broad ecological scales, likely having a major impact on species diversity and ecosystem function. I will use stage-structured Species Area Distributions and Species Biomass Distributions to quantify differences in structural heterogeneity in forest plots across a latitudinal gradient. Two types of forest stands will be compared: mixed-stage structure (heterogeneous), and single-stage structure (homogenous). By quantifying differences at each site, I hope to show that structural heterogeneity buffers extreme variation in climate, allowing for the maintenance of rare plant and arthropod populations.


My research will focus on management and restoration efforts that change structural and thermal heterogeneity in forest ecosystems. By combining theory and management, I hope to quantify levels of structural and thermal heterogeneity that minimize the effects of climate change in forest ecosystems. Highly structured forests are expected to better maintain rare plant and arthropod diversity, compared to single-stage structured forests, even after extreme climatic events.


Using methods described by O’Dwyer et al. (2009), I will measure demographics, Species Area Distributions, and Species Biomass Distributions in 1-hectare forest plots, allowing me to quantify structural heterogeneity across a latitudinal gradient. Within each plot, I will quantify plant and arthropod diversity prior to any treatments. The distribution of temperatures in the environment has been shown to be important for thermoregulation by ectothermic species; therefore, I will use iButton data-loggers to record differences in thermal heterogeneity within each plot. Following these measurements, I will modify the timing and quantity of rain events to mimic potential effects of climate change. Control plots will receive no treatment, but natural rainfall amounts will be measured within each plot to compare to treatment plots. The treatments will last for at least 3 years. During and immediately following the treatments, I will measure changes in plant and arthropod diversity, as well as any changes in structural heterogeneity. These experiments will test the importance of vertical structure in forest plots, and how structure and climate interact to change species abundances and distributions.

Expected Results:

When assessing the effects of stochastic climate variation, I expect to find that highly structured plots maintain biodiversity of plants and arthropods better than homogenous forest plots. The thermal heterogeneity in structured plots will allow ectothermic species to thermoregulate effectively, and maximize performance and reproduction. A high diversity of ectothermic animals will positively influence plant populations through plant-pollinator interactions, and potentially increase seed dispersal. Recent models also predict that predators are more able to control herbivorous insect populations in habitats with high thermal heterogeneity; reduced herbivory will increase plant fitness.

Potential to Further Environmental/Human Health Protection:

Forests have been heavily harvested worldwide. Broad scale clear-cuts have diminished natural structure once found in forest habitats, likely diminishing any beneficial buffering against climatic stochasticity. Habitat management plans need to be implemented that make it logical for land owners to re-establish natural heterogeneity once found in forest ecosystems. By re-establishing forest structure, using the management tools I propose, scientists and land managers can take an interactive and cooperative role in minimizing the effects of climate change. This proposal combines multiple disciplinary backgrounds, and therefore applies to those studying ecology, wildlife, physiology, and habitat management. Beyond the scope of science, promoting habitats that maintain biodiversity, even in the light of increased climatic stochasticity, offers interesting implications for farmers, conservationists, and the general public.

Supplemental Keywords:

biodiversity, structure, heterogeneity, forest, rainfall, temperature, climate change, latitudinal gradient,