小兴安岭丰林阔叶红松林木质物残体的贮量特征分析

Characteristics of woody debris in mixed broadleaved-Korean pine forest plot in Fenglin National Nature Reserve in Xiao Hinggan Mountains,China

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）, including coarse woody debris （diameter ≥ 10 cm, CWD） and fine woody debris （1 cm ≤diameter 〈10 cm, FWD） , is one of the most important components in forest ecosystems. This study aimed to understand the species composition, diameter distribution, existing types and decay classes of WD, and their relationships with stand factors in 30 hm2 plot of mixed broadleaved-Korean pine forest in Fenglin National Nature Reserve in Xiao Hinggan Mountains. The total volume of WD with diameter ≥ 1 cm was 104.26 m3/hm2. The volume proportion of FWD to CWD was 0.5：99.5 ; The diameter distribution of WD density showed typical reverse J-shaped curve, the small size WD （ ≤ 20 cm） was accounted for 52.9% of the total density. The volume of WD showed nearly J-shaped curve. The volume of Pinu~ koraiensis increased with increase of the diameter, the other species displayed almost normal distribution. Existing types of WD were mainly composed of trunk segment, uprooted blow-down and breakage at rootstock. As the increasing of diameters, the density and volume percentage of trunk segment decreased, and uprooted blow-down and breakage at rootstock initially increased, then decreased. The decay classes of CWD showed nearly normal distribution curve, peaked at the classes of Ⅲ and Ⅳ. The total density of WD was positively correlated with the total density of living tree （P 〈 0.05）. The total basal area of WD was negatively correlated with total volume, max diameter at breast height （DBH） and mean DBH of living tree （P 〈 0.05）. The total volume of WD was negatively correlated with the total basal area and the total volume of living tree （P 〈 0.05）. On the whole, the density, basal area and volume of classe Ⅲ, Ⅳ, Ⅴ were significantly correlated with the basic parameters of living tree.