U.S.-Hungary Research on a Cross-Continental Study of Controls on Soil Carbon and Nitrogen Dynamics

Oregon State University, Corvallis OR

Investigators

Abstract

INT 0002956 Lajtha This U.S.-Hungary research project involves a long-term study of controls on soil organic matter formation or "Detritus Input and Removal Treatments" (DIRT) at three established sites in the United States and one in Hungary. Kate Lajtha of Oregon State University serves as the U.S. principal investigator in cooperation with her Hungarian counterpart, Janos Atilla Toth of Kossuth University in Debrecen. The goal of DIRT is to assess how rates and sources of plant litter inputs control the accumulation and dynamics of organic matter and nutrients in forest soils over decadnal time scales. The U.S.-Hungarian research team intends to examine processes at multiple levels in the soil to explore the chemical and biological interconnections that lead to formation of humic materials over long time spans. Of special interest is the stabilization and retention of soil organic carbon (C) and inorganic and organic nitrogen (N) because soil organic matter decomposition processes appear to influence global carbon sequestration. The Hungarian Sikfokut long-term ecological research site that joins the U.S.-based effort via this project is a temperate deciduous oak forest located in Eger, Hungary. It brings a European site to the effort that has vegetation similar to participating eastern U.S. forest sites, yet one that exhibits significantly higher nitrogen inputs. Thus, cooperative research with Hungarian counterparts at Sikfokut offers a unique opportunity to test hypotheses in a structurally similar system with extreme N input and forest floor chemistry. The planned collaboration has three foci: a) an analysis of the controls on N dynamics and leaching; b) analysis of carbon dynamics due to interacting mechanisms of formation, stabilization, destabilization; and c) field soil respiration measurements. Results are expected to shed new light on the pathways of N and C sequestration and loss, across a large climatic and pollution history gradient. This cross-continental study of soil dynamics fulfills the program objectives of advancing scientific knowledge by enabling experts in the United States and Central Europe to combine complementary talents and share research resources in areas of strong mutual interest and competence.