不同林龄草类-兴安落叶松林粗木质残体特征

Coarse Woody Debris of Grass-Larix Gmelinii Forests in Different-Age

以大兴安岭草类-兴安落叶松林为对象,通过分析不同龄林粗木质残体(CWD)的物种组成、径级结构及腐烂等级,揭示了CWD的基础特征及贮量。结果表明:CWD密度、体积和生物量分别为400～1 650株.hm-2、6.73～203.09 m3.hm-2和3.45～104.33 t.hm-2。随着林分林龄的增加,CWD密度逐渐减少,体积和生物量均从幼龄林开始增加,到成熟林时达到高峰后开始下降。随着林分林龄的增加,高腐烂等级的CWD体积和生物量比例逐渐增加,幼中龄林和近熟林以Ⅰ～Ⅲ级腐烂为主,成过熟林以Ⅳ～Ⅴ级腐烂为主。随着径级的增加,CWD体积和生物量比例在中龄林先增加后降低,在近熟林、成熟林和过熟林中有逐渐增加的趋势。群落由兴安落叶松和白桦构成,兴安落叶松CWD在数量、体积和生物量上均占74%以上。

The research was conducted to ＂study the species composition, diameter class structure and decay class of coarse woody debris （CWD） of typical Grass-Larix grnelinii forest in Daxing＇ an Mountain for the characteristics and storage of CWD. The density, volume and biomass of CWD are 400-1 650 hm^-2 , 6.73-203.09 m3·hm^-2 and 3.45-104.33 t·hm^-2 , re- spectively. The density of CWD decreases with the increasing of stand age. Both the volume and the biomass of CWD reach the peak at the mature forest, and then decline. With the increasing of stand age, the volume and the biomass pro- portion of CWD at high decay class increase gradually. The decay classe focuses on Ⅰ-Ⅲ at young, middle-aged and near- mature forest, and Ⅳ-Ⅴ at mature and over-mature forest. With the increasing of DBH class, the proportions of CWD vol- ume and biomass increase first, decrease at middle-aged stand and increase at near-mature, mature and over-mature for- est. The orooortions of density, volume and biomass of L. emelinii CWD are above 74%.