开敞度调控对阔叶红松人工天然混交林上层阔叶树的影响

Effect of Community Structure Regulation on Upper-Layer Broad-Leaved Trees in a Mixed Forest of Planted Korean Pine and Naturally-regenerated Broad-Leaved Trees

以阔叶红松人工天然混交林为对象,以林下红松个体开敞度(K)为主要数量控制指标进行群落结构量化调整,研究调整后6年间上层阔叶树直径和树高生长及树种组成和物种多样性的变化。结果表明:量化调整明显促进了保留阔叶树的直径生长和树高生长,各处理累计的定期生长量均高于对照,且随调整时期延长差异不断加大;K=1.5和K=2.0水平的年生长量与对照林分的差异基本都达到显著水平;量化调整改善了上层阔叶树树种组成,水曲柳、黄檗和胡桃楸等珍贵阔叶树种比例上升,白桦和山杨等先锋树种比例下降;量化调整使阔叶树物种丰富度增加,物种多样性和均匀度增加或差别不大,生态优势度降低或差别不大。

In this paper, the diameter and height increment, species composition and species diversity of the upper- layer broad-leaved trees were measured during 6 years period after stand structure quantitative regulation with opening degree of the under-canopy planted P. koraiensis is trees in a mixed forest of planted Pinus koraiens with natural broad- leaved trees. The results showed that the quantitative regulation of stand structure （QR） evidently promoted the diameter and height increment of upper-layer broadleaved trees （UBT）. Periodic increment of UBT in various QR treatments was all higher ihan that in control and the increment was increased along with the elongation of QR period. The annual increment of UBT in K = 1.5 and K = 2.0 treatments was significantly higher than that in control. QR improved the species composition of UBT in the treated plots, the proportion of valuable hardwood species like Fraxinas mandshurica, Phellodendron amurense and Juglans mandshurica was increased, and the proportion of pioneer species like Betula platyphylla and Populus davidiana was decreased. QR increased the species richness of UBT, increased species diversity and uniform degree of UBT or no changes, decreased ecological dominance or no changes.