Log Decomposition Processes as Influenced by Heterotroph Community Structure

将对分解的原木进行详细的过程级和社区级研究，这是俄勒冈州H.J.安德鲁斯LTER站点长期木材腐烂研究的一部分。具体而言，研究将重点完成三个研究任务。首先，将完成一项为期两年的关于四种腐烂原木营养动态的研究。有关原木营养成分变化的数据将与通过固氮等过程输入的营养信息以及通过破碎和淋滤等过程输出的营养信息相结合。其次，将研究1985年野外采集的原木，以确定固氮作用、真菌群落分布和与分解者群落相关的酶活性。这项工作将完成对木材腐烂季节模式的研究。第三，对1985年采伐的测井资料进行萜烯和酚含量分析。其中一些化合物被认为是蛀木昆虫的引诱剂和/或分解抑制剂。本研究的意义在于，它将有助于我们了解木材腐烂在森林生态系统养分循环中的作用。在太平洋西北部的原始森林中，倒下的原木和其他木质碎片占地上有机物（活的和死的有机物）的22%，占地上碎屑的81%。在这些森林系统中，这些大量的死木质材料可能是重要的营养物质仓库和营养动态调节器。肖沃尔特博士和他的同事们在这一研究领域有着良好的生产力记录。他们可以得到的制度支持是优越的。

Detailed process-level and community-level studies will beconducted on decomposing logs that are part of a long-term logdecay study centered at the H.J. Andrews LTER site in Oregon. Specifically, the research will focus on completing threeresearch tasks. First, a two-year study of nutrient dynamics infour species of decaying logs will be finished. Data on changesin nutrient content of the logs will be integrated withinformation on nutrient inputs through processes such as nitrogenfixation, and outputs through processes such as fragmentation andleaching. Second, logs set in the field 1985, will be studied todetermine nitrogen fixation, fungal community distribution andenzyme activity associated with the decomposer community. Thiseffort will complete a study of seasonal patterns in log decay. And third, analyses of terpene and phenol content of the logs setout in 1985, will be completed. Some of these compounds arethought to serve as attractants for wood-boring insects and/or asinhibitors of decomposition. The significance of this research is that it will help us tounderstand the role of log decay in nutrient cycling in forestecosystem. In old-growth forests of the Pacific Northwest,downed logs and other woody debris comprise up to 22% of above-ground organic mass (live and dead organic matter) and 81% ofaboveground detritus. This large mass of dead woody material maywell serve as an important storehouse of nutrients and regulatorof nutrient dynamics in these forest systems. Dr. Showalter and his colleagues have good records ofproductivity in this research area. The institutional supportavailable to them is superior.