岷江上游大沟流域油松人工幼林生物量组成及其影响因素

Biomass Compositions of Pinus tabulaeformis Plantation and Their Relationships in the Dagou Valley of the Upper Minjiang River

为了揭示人工林不同层次的生物量组成关系及其影响因素,选择岷江上游大沟流域的油松人工林,调查分析了林分不同层次生物量组成及其关系,探讨了乔木密度、坡向、海拔对生物量的影响。发现:1)两种林龄油松人工林生物量分配基本一致,即,乔木层>灌木层>草本层;乔木各构件生物量大小顺序为:枝>干>叶>根>果/皮。同时指出,枝叶对下木层生物量的影响显著。2)乔木密度显著控制了林分生物量及其组成,在本调查范围内坡向的影响似乎不明显;海拔对22 a油松影响显著,而24 a的不显著;综合分析表明,本区域内,22 a油松保持在3 800株/hm2左右和24 a在3 500株/hm2左右时,有助于林分生物量的稳定与提高,促进生态系统功能的恢复。

This paper studies on biomass distribution of different layers and their relationships in 22 and 24 ages＇Pinus tabulaeformis artificial forests in the Dagou valley in the upper of Minjiang River; and discusses the effect of arbor density, slope aspects and elevation on biomass, for revealing the relationship and composition of different layers＇biomass and their influential factors. The ,results show that： 1 ） Both of 22years and 24years P. tabulaeformis artificial forests displayed a similar pattern of biomass, which is, arbor 〉 shrub 〉 herb. Biomass allocation of P. tabulaeformis is following, branch 〉tnmk 〉 leaf 〉 root 〉 bark/fruit. It was also found that the biomass of under-shrub and under-herb were influenced obviously by branch and leaf biomass of P. tabulaeformis; 2） The arbor densities have influenced the biomass and their distribution significantly on both forests. However, it seems that slope aspects have no significant effects on biomass. Biomass in 22years P. tabulaeformis forests was also influenced by elevation, but the same effect was not found in 24years forests. By comprehensive analysis, it indicates that the forests biomass will arrive at their equilibriums at about 3 800/ha in 22years P. tabulaeformis forests and about 3 500/ha in 24years in the area, so they will promote the restoration progress and improve the functions of eco-system better.