DISSERTATION RESEARCH:Will CO2-mediated Increases in Fine-root Litter Progressively Decrease Forest N Availability by Increasing N Immobilization in Soil Organic Matter?

土壤具有长期储存碳的能力。 在土壤剖面中，植物遗骸在多大程度上不被分解，将决定土壤中储存的碳和氮的数量，以应对大气中二氧化碳浓度的上升。 本研究旨在探讨细根凋落物分解与土壤有机质中碳、氮固定的关系。 细根和土壤有机质与贫化碳-13同位素签名将采取从CO2富集实验在落叶林的立场和分解的相互移植实验。分解细根中的碳将被量化，因为它被转移到具有不同寿命的土壤有机质组分中。该项目的结果将促进对森林生态系统中调节地上和地下碳储存的陆地过程的理解，并为用于预测生态系统对气候变化的反应的模型提供信息。

Soils have the capacity to store carbon for a long time. The degree to which plant remains are protected from decomposition in the soil profile will determine the amount of carbon and nitrogen stored in soils in response to rising atmospheric concentrations of carbon dioxide. The objective of this research is to mechanistically link the decomposition of fine-root litter to carbon and nitrogen immobilization in soil organic matter. Fine roots and soil organic matter with a depleted carbon-13 isotope signature will be taken from a CO2-enrichment experiment in a deciduous forest stand and decomposed in a reciprocal transplant experiment. Carbon from the decomposing fine roots will be quantified as it is transferred to fractions of soil organic matter with different longevities. Results of this project will advance the understanding of terrestrial processes that regulate above- and belowground carbon storage in forested ecosystems, and inform models used to predict ecosystem responses to climatic change.