论文部分内容阅读
木质物残体(WD)包括粗木质残体(CWD,直径D≥10 cm)和细木质残体(FWD,1 cm≤D<10 cm),是森林生态系统中重要的组成部分。以小兴安岭丰林阔叶红松(Pinus koraiensis)林30 hm2监测样地木质物残体为研究对象,分析了WD的物种组成、径级结构、存在形式、腐烂等级的分布及其与林分因子的相关关系。结果表明:样地内D≥1 cm的WD材积为104.26 m3/hm2,其中FWD与CWD的材积比为0.5∶99.5;WD密度的径级分布呈典型的倒“J”形,且以小径级(≤20 cm)的WD为主(52.9%)。WD的材积呈近“J”形,红松WD的材积随着径级的增加而增加,其余树种呈近正态分布。WD的存在形式主要以树段、拔根倒和干基折断为主,随着径级增加,树段的密度和材积比例逐渐减小,拔根倒和干基折断的密度和材积比例先增加后减少。CWD的腐烂等级呈近正态分布,主要集中在Ⅲ、Ⅳ等级。WD的总密度与活立木的总密度显著正相关(P<0.05)。WD的总断面积与活立木的总体积、最大胸径(DBH)、平均DBH均显著负相关(P<0.05)。WD总体积与活立木的总断面积、总体积显著负相关(P<0.05)。总体来看Ⅲ、Ⅵ、Ⅴ腐烂等级WD的密度、断面积和体积均与活立木的基本参数显著相关。
Woody debris (WD) includes coarse woody debris (CWD, D≥10 cm in diameter) and fine wood debris (FWD, 1 cm≤D <10 cm), which are important components of forest ecosystems. Taking wood residues from 30-hm2 monitoring site of Pinus koraiensis forest in Xiaoxing’an Mountains as the research object, the distributions of species composition, diameter-class structure, existing forms and decay grades of WD were analyzed and their correlations with stand factors relationship. The results showed that the WD volume of D ≥ 1 cm in the plot was 104.26 m3 / hm2, and the volume ratio of FWD to CWD was 0.5:99.5. The diameter distribution of WD density was typical inverted J shape, Grade (≤20 cm) WD is the main (52.9%). The volume of WD was nearly “J” -shaped, and the volume of Pinus sylvestris WD increased with the increase of diameter. The rest of the species was nearly normal distribution. The dominant forms of WD are mainly tree branches, roots and inverted basal folds. With the increase of diameter, the density and volume ratio of tree segments gradually decrease, and the density and volume ratio of broken roots and dry basis first increase After reduction. The decay grade of CWD was nearly normal distribution, mainly concentrated in Ⅲ, Ⅳ grade. The total density of WD was positively correlated with the total density of live wood (P <0.05). The total area of WD was negatively correlated with the total volume of DBH, DBH and DBH (P <0.05). The total volume of WD was significantly and negatively correlated with the total area and total volume of living wood (P <0.05). Overall, the density, cross-sectional area and volume of Ⅲ, Ⅵ, Ⅴ decay grades WD were significantly correlated with the basic parameters of live wood.