Soil carbon storage is determined to a large degree by the balance between plant productivity and organic matter decay. Soil microorganisms are the primary decomposers of organic matter and their metabolism controls how much carbon is lost from the soil and returned to the atmosphere as carbon dioxide. One of the key factors determining the fate of soil carbon is the efficiency with which soil microorganisms convert organic matter to microbial biomass. Despite its importance in determining soil carbon dynamics, little is known about how microbial efficiency responds to environmental change. In this project, a new technique, calorespirometry will be used to make in situ measurements of microbial efficiency in soils exposed to chronic warming and nitrogen fertilization.
Global change is altering the functioning of terrestrial ecosystems. This project will focus on two aspects of global change that have particular significance for the northeastern U.S., warming and nitrogen deposition. This project will provide evidence for how warming and nitrogen fertilization interact to influence microbial metabolism and carbon loss from soils, and will provide valuable data for input into global carbon and soil organic matter models. Additionally, a five-year outreach program will be developed for the State of New Hampshire to provide accessible information to the general public on the services that ecosystems provide (e.g., air and water quality), and how global change is impacting the ability of ecosystems to maintain these services. This objective will be accomplished via a website, public service announcements on local National Public Radio stations, posters on public transport systems, and an ecosystems services module for New Hampshire Project Learning Tree, a statewide environmental education program.
