论文部分内容阅读
以大兴安岭杜香-兴安落叶松林为对象,采用2类标准分析不同年龄林分粗木质残体(CWD)的物种组成、径级结构及腐烂等级,揭示CWD特征及贮量的变化。结果表明:Harmon标准计算的密度、体积和生物量为350～659株·hm-2、2.64～38.27m3·hm-2和1.13～8.52t·hm-2,分别比LTER标准高出52.07%～92.38%、17.44%～63.13%和16.88%～22.11%。随着林分年龄的增加,Harmon标准计算的CWD密度呈“U”型分布,体积和生物量均呈近似正态分布;LTER标准计算的CWD密度从中龄林开始逐渐上升,体积和生物量则逐渐降低。随着林分年龄的增加,2类标准计算的腐烂等级高的CWD密度、体积和生物量比例均逐渐增加,其中幼中龄林以Ⅰ-Ⅱ级腐烂为主,近成熟林以Ⅱ-Ⅲ级为主。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76%以上。
Taking Duxing-Xing’an Larix gmelinii forest in Daxinganling as an example, the species composition, diameter structure and decay grade of coarse woody debris (CWD) in different ages were analyzed by using two kinds of criteria to reveal the changes of CWD characteristics and stock volume. The results showed that the Harmon standard calculated the density, volume and biomass of 350 ~ 659 plants · hm-2 · 2 · 64 · 38.27m · hm-2 and 1.13 ~ 8.52 t · hm-2, 92.38%, 17.44% ~ 63.13% and 16.88% ~ 22.11%. With the increase of stand ages, the CW standard density calculated by the Harmon standard showed a “U” shape distribution with a nearly normal distribution of volume and biomass. The CWD density calculated by the LTER standard gradually increased from the middle-aged forest and the volume and biomass The amount is gradually reduced. With the increase of stand ages, the density, volume and biomass of CWD with higher rotten grades calculated by the two standards increased gradually. Among them, the young middle-aged stands were mainly Ⅰ-Ⅱ rots, and the mature mature stands Ⅱ-Ⅲ Mainly based. The community is composed of Larix gmelinii and Betula platyphylla, CWA Larix chinensis accounts for more than 76% of its volume, volume and biomass.