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

INT 0002956 Lajtha这个美国-匈牙利研究项目涉及一项长期研究，对美国三个已建立的地点和匈牙利的一个地点的土壤有机质形成或“碎屑输入和清除处理”(污垢)的控制进行研究。俄勒冈州立大学的凯特·拉伊塔与匈牙利德布勒森科苏斯大学的亚诺斯·阿蒂拉·托斯合作，担任美国首席研究员。土壤的目标是评估植物凋落物输入的速率和来源如何在十年时间尺度上控制森林土壤中有机质和养分的积累和动态。美国-匈牙利研究小组打算研究土壤中多个层面的过程，以探索导致腐殖质长时间形成的化学和生物相互联系。特别令人感兴趣的是土壤有机碳(C)和无机和有机氮(N)的稳定和保持，因为土壤有机质分解过程似乎影响全球碳固定。匈牙利锡克福库特长期生态研究地点是位于匈牙利埃格尔的一片温带落叶栎林，该地点通过该项目加入了美国的努力。它将一个欧洲地点带入了这一努力，该地点的植被类似于参与的美国东部森林地点，但表现出明显更高的氮素输入。因此，与匈牙利同行在锡克福库特的合作研究提供了一个独特的机会，可以在具有极端N输入和森林地面化学的结构相似的系统中测试假设。计划中的合作有三个重点：a)对氮素动态和淋溶的控制进行分析；b)由于形成、稳定和不稳定的相互作用机制而进行的碳动态分析；以及c)田间土壤呼吸测量。这项关于土壤动力学的跨洲研究通过使美国和中欧的专家能够结合互补的人才并在具有强烈的共同兴趣和能力的领域共享研究资源，实现了推进科学知识的计划目标。

INT 0002956LajthaThis 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.