Moisture and Saprotroph Effects on Log Decomposition Processes

水分和腐生菌对原木分解过程的影响

• 批准号: 9408169
• 负责人: Timothy Schowalter
• 金额: $ 54.59万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9408169&HistoricalAwards=false
• 关键词: Moisture; Saprotroph; Effects; Log; Decomposition

Decomposition of woody litter is a major process contributing to biogeochemical cycling and productivity in forested ecosystems. Because woody litter can amount to 22% of above biomass, it represents a substantial source of nutrients for plant uptake and carbon dioxide for release to the atmosphere. However, factors affecting decomposition and rate of carbon dioxide and nutrient release from logs remain poorly known. Saprotroph colonization patterns and biodiversity, as affected by moisture content, have been ascribed and important role in the decomposition process. The importance of these factors has not been evaluated experimentally. Our objective is to evaluate the influence of log moisture content and Saprotroph community development on log decomposition and mineralization rates. We will test hypothesis that (1) initial rates of decomposition processes are determined by the depth of penetration by insects and establishment of decay vs. non-decay fungi, (2) decomposition rate is a function of moisture content of logs, and (3) decomposition rate is positively related to the diversity of the saprotroph community. We expect decomposition and mineralization rates to increase incrementally from uncolonized logs to logs penetrated by insect tunnels, to insect tunnels colonized by decay and/or non-decay fungi. These hypotheses will be tested by comparing changes in wood density and carbon/nutrient losses due to fragmentation, respiration, and leaching in Douglas-fir logs with manipulated moisture content and manipulated initial saprotroph colonization (phloem borers vs. sapwood borers, non-decay fungi vs. decay fungi). Manipulation of saprotroph establishment in decomposing logs will indicate the functional importance of biodiversity to this ecosystem process.

森林凋落物分解是森林生态系统中重要的生态地球化学循环和生产力过程。 由于木质凋落物可占上述生物量的22%，因此它是植物吸收的营养物质和释放到大气中的二氧化碳的重要来源。 然而，影响木材分解和二氧化碳及养分释放速率的因素仍然知之甚少。 腐解生物的定殖模式和生物多样性，受水分含量的影响，已被归因和分解过程中的重要作用。 这些因素的重要性尚未通过实验进行评估。 我们的目标是评估原木含水量和腐解生物群落发育对原木分解和矿化速率的影响。 我们将检验以下假设：（1）分解过程的初始速率取决于昆虫的渗透深度和腐烂真菌与非腐烂真菌的建立，（2）分解速率是原木含水量的函数，（3）分解速率与腐生物群落的多样性呈正相关。 我们预计分解和矿化率增加，从未殖民日志日志的日志穿透昆虫隧道，昆虫隧道殖民腐烂和/或非腐烂真菌。 这些假设将通过比较木材密度和碳/养分损失的变化，由于破碎，呼吸作用，并在花旗松日志与操纵水分含量和操纵初始腐殖菌定植（韧皮部蛀虫与边材蛀虫，非腐烂真菌与腐烂真菌）的浸出进行测试。 操纵腐营建立在分解日志将表明生物多样性的功能重要性，这个生态系统的过程。