Peatlands cover only 3% of Earth’s land surface but contain about 20% of the global soil carbon pool. Peat deposits originated from woody plants and moss-generated litter. Because of cold, oxygen-poor conditions, the carbon contained in northern peatlands has accumulated for thousands of years. Under current warming trends and consistent with climate projections, such accumulations of carbon are now viewed as being vulnerable to further decomposition or mineralization. If global temperatures warm as projected at higher latitudes, these peatlands could release large amounts of greenhouse gases such as carbon dioxide (CO2) and methane (CH4) that could accelerate global warming. Our ability to predict or simulate the fate of the stored carbon in response to climatic disruption remains hampered by a limited understanding of the controls of carbon turnover and the composition and functioning of peatland ecosystems.
Aboveground warming chambers in final phase of construction. Image courtesy Oak Ridge National Laboratory.
To identify and quantify these critical environmental response mechanisms, the Terrestrial Ecosystem Science program within the Department of Energy’s (DOE) Office of Biological and Environmental Research is supporting a whole-ecosystem experiment in an ombrotrophic bog (i.e., a raised bog that receives all water and nutrients from direct precipitation) located in the Marcell Experimental Forest of northern Minnesota. The Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) project, led by Oak Ridge National Laboratory, will enable the assessment of ecological responses across multiple spatial scales—including microbial communities, moss populations, various higher plant types, and some animal groups. The project will evaluate a wide range of increased temperatures and levels of elevated atmospheric CO2 concentrations. Direct and indirect effects of the experimental perturbations will be tracked and analyzed over a decade. This comprehensive suite of spruce-peatland process studies and observations is being strongly linked to model development and application requirements for improving process representation, calibrating models, and evaluating model predictions for boreal systems. SPRUCE is a cooperative joint venture among scientists from DOE national laboratories, the U.S. Department of Agriculture Forest Service, and universities.
The experiment’s overarching science questions cover ecosystem responses ranging from the microbe to landscape scale. They include:
Environmental monitoring station located on the S-1 Bog at the USDA Forest Service, Marcell Experimental Forest. Image courtesy Oak Ridge National Laboratory.
Answers to these questions will provide insights not only for small-scale processes but also for landscape-relevant water, carbon, and energy fluxes for similar peatlands. Results will inform higher-order models of vegetation responses under various levels of climatic warming and associated end-of-century atmospheric change.
Meet FRED: A Global Fine-Root Ecology Database
A global Fine-Root Ecology Database to improve belowground understanding and modeling.