湖南莽山针阔混交林粗死木质残体的研究

Study on coarse woody debris of coniferous and broad-leaved mixed forest in Mangshan Mountain of Hunan Province

通过实地调查,对湖南莽山国家森林公园针阔混交林的粗死木质残体(CWD)现状进行研究,以揭示莽山典型森林CWD的发生特征及分布规律,为莽山森林资源的经营与保护提供理论依据。通过在莽山针阔混交林内设置一个面积0.15 hm^(2)样地,并将其分成15个小样方,调查分析每个小样方内CWD的输入方式、径级结构、贮存量和腐烂等级。莽山CWD的输入方式包括倒木、枯立木和枯枝,大径级倒木是CWD贮存量的主要组成部分,针阔混交林CWD的总贮存量为108.59 t·hm^(-2)。从腐烂等级来看,CWD的腐烂等级以Ⅲ级、Ⅳ级较多,分别占其总贮存量的29.3%、42.8%,Ⅰ级、Ⅱ级腐烂程度都较少。莽山针阔混交林的CWD贮存量大于国内其他森林,且以直径30cm以上的倒木和枯立木为主,腐烂等级高,这可能与冰灾、风害的影响有关。

In the present work,coarse woody debris(CWD)of coniferous and broad-leaved mixed forest in Mangshan Mountain National Forest Park of Hunan Province was studied based on field investigation,in order to understand the occurrence characteristics and distribution law of CWD in typical forests of Mangshan Mountain,and provide theoretical basis for the management and protection of forest resources in Mangshan Mountain.A sample plot of 0.15 hm 2 was set up in coniferous and broad-leaved mixed forest in Mangshan Mountain,and the plot was divided into 15 subplots.CWD investigation was carried out in the subplot and input mode,while structural characteristics of diameter class,storage capacity and decay grade of CWD were investigated and recorded.CWD input modes of Mangshan Mountain coniferous and broad-leaved mixed forest included fallen tree,dead standing tree and dead branch.The total storage capacity of CWD is 108.59 t·hm^(-2),and larger diameter fallen trees consist of the main proportion.From the point of decay grade of CWD,grade III and IV account for 29.3% and 42.8% of the total storage respectively,while the decay grade I and II have a small proportion.The storage capacity of CWD in Mangshan Mountain natural forest is higher than other forests.The most storage comes from fallen trees,while the diameter of dead trees was larger than 30 cm.The CWD of coniferous and broad-leaved mixed forest may have been affected by ice storm damage of 2008.