DISSERTATION RESEARCH: Response of Decomposer Fungi to Simultaneous Warming and Nitrogen Additions

分解真菌是温带森林生态系统中的主要腐朽媒介。 从这个意义上说，它们在生态系统功能中发挥着至关重要的作用，因为它们的活动有助于调节土壤碳和养分循环。 本博士论文旨在探讨分解真菌的多样性与木材腐朽的关系。 它还询问了气候变化和氮沉降等主要环境干扰是否会破坏这种关系。 为了解决真菌分解者群落、环境变化和土壤养分循环之间的相互作用，在哈佛森林长期土壤变暖×氮添加研究中将红枫木材埋在土壤中。 这个实验模拟了全球变暖和酸雨导致的温度升高和氮输入。 红枫作为土壤真菌定居和分解的食物来源。 12个月、18个月和24个月后，红枫将被从土壤中取出，并评估其腐烂状态。 与此同时，将使用提取、克隆和测序真菌DNA的方法来鉴定在木材诱饵外部和内部定居的真菌。 这种方法将允许定量评估真菌如何应对环境压力，反过来，这种反应如何可能对生态系统功能产生不利影响。 更广泛的意义是，它将提供有关土壤真菌如何促进大规模进程的信息，以及在制定土地保护和恢复计划时应如何考虑它们。 对本科生助理的培训将是博士生活动的额外好处。

Decomposer fungi are the primary decay agents in temperate forest ecosystems. In this sense they play a crucial role in ecosystem function since their activities help to regulate soil carbon and nutrient cycles. This doctoral dissertation study examines whether there is relationship between the diversity of decomposer fungi and wood decay. It also asks if major environmental disturbances such as climate change and nitrogen deposition can disrupt this relationship. To address interactions among the fungal decomposer community, environmental change, and soil nutrient cycles, red maple wood was buried in soil at the Harvard Forest long-term Soil Warming × Nitrogen Addition Study. This experiment mimics the increased temperatures and nitrogen inputs that occur as the result of global warming and acid rain. The red maple acts as a food source that soil fungi colonize and decompose. After 12, 18, and 24 months, the red maple will be removed from the soil and assessed for its state of decay. At the same time, the fungi that colonized both the outside and the inside of the wood bait will be identified using a method that extracts, clones, and sequences fungal DNA. This approach will allow the quantitative assessment of how fungi respond to environmental stress, and in turn, how this response might adversely impact ecosystem function. A broader implication is that it will provide information on how soil fungi contribute to large scale processes, and how they should be considered when devising land conservation and restoration plans. Training for an undergraduate assistant will be an added benefit of the doctoral student's activities.