Global Change From the Ground Up: Soil Microbial Diversity in a Climate and Land-Use Change Experiment

EPA Grant Number: F13B20373
Title: Global Change From the Ground Up: Soil Microbial Diversity in a Climate and Land-Use Change Experiment
Investigators: MacRae-Crerar, Aurora Alexandra
Institution: University of Pennsylvania
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2014 through September 1, 2016
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2013) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Ecology


Soil and the myriad microbes it contains are the foundation of ecosystem processes, but how these ecosystems respond to global change is unknown. Global change includes shifts in both climate and land use. This research uses DNA sequencing to investigate if and how soil microbial communities respond to treatments that simulate climate and landuse change—including temperature, moisture and grazing. Results will be examined for evidence of microbial sentinels that may act as indicators of soil health and predictors of impending change.


In collaboration with the PIRE Mongolia Project, fieldwork has been done in northern Mongolia at an International Long-Term Ecological Research site near Lake Hövsgöl, where significant changes in climate and grazing status have been observed. Soil samples were collected in three habitats at this site: forest, steppe and riparian. Within the steppe, samples were collected over the course of 4 years (2009–2012) from control areas and areas that included grazing and climate manipulation treatments along a topographical gradient. Samples were sequenced by the Earth Microbiome Project, allowing the identification and quantification of soil bacteria. Bioinformatic analysis investigating the patterns seen across treatments and the relationship of patterns to environmental variables is underway.

Expected Results:

Despite the innate heterogeneity of the soil, distinct bacterial communities should be represented in each experimental treatment. The climate manipulation treatment, which both warms and dries the soil, is expected to decrease bacterial diversity. The grazing treatment is expected to stimulate decomposition and the availability of heterogeneous substrates, allowing a projected increase in bacterial diversity. A combination of both treatments could likely result in relatively intermediate levels of bacterial diversity.

Potential to Further Environmental/Human Health Protection

Biological diversity generally strengthens desirable ecosystem states by increasing ecosystem resilience. Identifying the factors that contribute to soil microbial diversity is key to understanding soil health, which is the foundation of healthy terrestrial ecosystems.

Supplemental Keywords:

climate change, land use, soil biome

Progress and Final Reports:

  • 2015
  • Final