Mechanisms controlling soil carbon sequestration under atmospheric nitrogen deposition

Content Provider	United States Department of Energy Office of Scientific and Technical Information (OSTI.GOV)
Author	Sinsabaugh, R. L. Zak, D. R. Moorhead, D. L.
Organization	University of New Mexico
Abstract	Increased atmospheric nitrogen (N) deposition can alter the processing and storage of organic carbon in soils. In 2000, we began studying the effects of simulated atmospheric N deposition on soil carbon dynamics in three types of northern temperate forest that occur across a wide geographic range in the Upper Great Lakes region. These ecosystems range from 100% oak in the overstory (black oak-white oak ecosystem; BOWO) to 0% overstory oak (sugar maple-basswood; SMBW) and include the sugar maple-red oak ecosystem (SMRO) that has intermediate oak abundance. The leaf litter biochemistry of these ecosystems range from highly lignified litter (BOWO) to litter of low lignin content (SMBW). We selected three replicate stands of each ecosystem type and established three plots in each stand. Each plot was randomly assigned one of three levels of N deposition (0, 30 & 80 kg N ha-1 y-1) imposed by adding NaNO3 in six equal increments applied over the growing season. Through experiments ranging from the molecular to the ecosystem scales, we produced a conceptual framework that describes the biogeochemistry of soil carbon storage in N-saturated ecosystems as the product of interactions between the composition of plant litter, the composition of the soil microbial community and the expression of extracellular enzyme activities. A key finding is that atmospheric N deposition can increase or decrease the soil C storage by modifying the expression of extracellular enzymes by soil microbial communities. The critical interactions within this conceptual framework have been incorporated into a new class of simulations called guild decomposition models.
Sponsorship	USDOE Office of Science (SC)
Related Links	https://www.osti.gov/biblio/923800
File Format	PDF
DOI	10.2172/923800
Language	English
Publisher Date	2008-02-19
Publisher Place	United States
Access Restriction	Open
Subject Keyword	ENVIRONMENTAL SCIENCES ABUNDANCE BIOCHEMISTRY BIOGEOCHEMISTRY CARBON CARBON SEQUESTRATION COMMUNITIES DEPOSITION ECOSYSTEMS ENZYMES FORESTS LIGNIN NITROGEN OAKS PROCESSING SACCHAROSE SOILS STORAGE carbon sequestration nitrogen deposition soil
Content Type	Text
Resource Type	Technical Report