Relevant study subjects on nitrogen dynamics and cycles in forested catchment and expected strategies

Abstract

After the Industrial Revolution, anthropogenic nitrogen N emission to the atmosphere has reached unprecedented level, and Nitrogen Saturation has correspondingly been reported in the forested areas within the high N deposition regions of Europe and North America. Mechanisms of nitrogen saturation have previously been studied through biogeochemical methodologies; however, N dynamics in catchment scale could not be described sufficiently, because geographical variability of catchment characteristics such as hydrologic properties is generally large and its effects provide various responses. We propose new strategy depending upon microbial ecological approach to reconstruct the mechanistic understandings on previously reported biogeochemical responses to the environmental changes. Combined usage of novel isotopic techniques on bioelements and newly advanced gene analysis using functional genes will have potential to provide insightful information on spatiotem-poral heterogeneity and non linear responses of N dynamics in forested ecosystems.