Prairie Heating and CO2 Enrichment (PHACE)

The Pendall Lab group is investigating how plant-microbe interactions regulate soil carbon cycling within an ongoing, state-of-the-art, manipulative climate change experiment in grassland near Cheyenne, Wyoming, the Prairie Heating and CO2 Enrichment (PHACE) experiment. Thirty plots are exposed to combinations of climate conditions, including warming and CO2 conditions expected to occur before the end of the 21st century, and altered precipitation. An important component of the experiment is the comparison of carbon and nutrient cycling between native and disturbed grassland with distinct plant communities, including invasive species.This project is expected to reduce uncertainties related to interactions between soil nutrients, biological communities and climate change, leading to improved predictions of future atmospheric CO2 concentrations and associated warming effects.
Our central hypothesis is that community-scale plant and microbial traits interact at the root-soil interface to regulate decomposition of SOM, through adjustments in microbial community composition and exoenzyme stoichiometric balance that result from plant responses to climate change and disturbance (Figure 1).

The PHACE project is led by Jack Morgan, of the USDA Agricultural Research Station, in Fort Collins, CO. The ARS web page for the project provides a great overview of the individuals involved, the infrastructure, and current progress.

Matt Wallenstein and his group have collaborated on the PHACE project since 2008, evaluating enzymatic and microbial community responses to the global change treatments.

The new Summer Soil Institute at Colorado State University ( will bring students to the PHACE field site for sampling and analyses.

Click here to view more photos from the field.