红松活立木干基腐朽程度定量表征及与立地土壤因子关系

Our previous studies showed that butt rot rate of Pinus Koraiensis standing trees was high both in natural forest and plantation, 50% for mature and over-mature stands. Site soil provides water and nutrients for standing trees and affects the survival environment of decay fungi in the trees. However, the intrinsic relationship between butt rot and site soil factors is unclear. Moreover, the quantitative characterization of butt rot degree has also not been achieved yet. Based on this, Pinus Koraiensis standing trees in Xiaoxinganling Forest Region are selected as the study objects in this project, the research content is: (1)to study the change mechanism of characteristic values, from macroscopic and microcosmic levels, obtained by electrical resistance, stress wave and Resistograph methods for detecting different stage butt rot in standing trees, and further to analyze the quantitative relationships between the internal and external testing indicators, which were used to quantitatively characterize butt rot degree; (2) to study the relationships between butt rot degrees and site soil physical, chemical and microbiological characteristics, which aim to determine site soil key factors influencing butt rot and to explain the effect mechanism. The research results of the project can provide the basic data for stand quality assessment, forest management measures adjustment and rare tree species protection.

前期研究表明，天然林和人工林红松活立木干基腐朽率严重，成过熟林达50%。立地土壤为活立木生长输送养分和水分，影响活立木内腐朽菌的生存环境。干基腐朽与立地土壤因子的内在关系目前尚不清楚，干基腐朽程度也未实现定量表征。因此本项目以此为切入点，以小兴安岭珍稀树种红松活立木为研究对象，从宏观、微观层面研究活立木干基不同腐朽程度下电阻、应力波及阻抗检测特征值变化机理与程度，量化分析干基腐朽内部与外部定量检测诸多表征指标的关系，实现干基腐朽程度的定量表征；通过研究干基腐朽程度与立地土壤物理、化学和微生物特性的关系，确定影响干基腐朽的立地土壤关键驱动因子，揭示干基腐朽程度对关键驱动因子变化的响应程度与机理。研究结果可为林分质量评估、森林经营措施调整和珍稀树种保护提供基础数据。

前期研究表明，天然林和人工林红松活立木干基腐朽率严重，成过熟林达50%。立地土壤为活立木生长输送养分和水分，影响活立木内腐朽菌的生存环境。干基腐朽与立地土壤因子的内在关系目前尚不清楚，干基腐朽程度也未实现定量表征。因此本项目以此为切入点，以小兴安岭珍稀树种红松活立木为研究对象，从宏观层面上研究了活立木干基不同腐朽程度下电阻、应力波及阻抗检测特征值变化机理与程度，并针对不同腐朽程度确定了定量检测方法；在微观层面上，通过分析活立木内部不同化学指标的变化，实现了活立木干基内部腐朽程度的定量表征；通过研究干基腐朽程度与立地土壤物理、化学和微生物特性的关系，确定了影响干基腐朽的立地土壤关键驱动因子，其中主要包括干基处含水率、土壤有机质含量、坡向、坡位、光照强度、林区内温度及边心材含水率，同时还对上述因子与干基腐朽进行了全面的相关性分析，进而揭示了干基腐朽程度对关键驱动因子变化的响应程度与机理。研究结果可为林分质量评估、森林经营措施调整和珍稀树种保护提供基础数据。