川西亚高山暗针叶林恢复过程中不同恢复阶段的定量分析

Quantitative analysis of different restoration stages during natural succession processes of subalpine dark brown coniferous forests in western Sichuan,China

以空间代替时间的方法,运用种间联结测定、主成分分析和最优分割法对川西亚高山箭竹-暗针叶林和藓类-暗针叶林经采伐后自然恢复形成的不同恢复系列（20、30、40和50年）,以及未被采伐而保留下来的160～200年生暗针叶老龄林进行恢复阶段的定量分析.结果表明：藓类和箭竹暗针叶次生林向暗针叶老龄林恢复过程中,红桦、卧龙柳、五角槭、疏花槭、康定野樱桃、挂苦绣球、椴树和川滇柳归并为衰退种组;湖北花楸、陕甘花楸和微毛野樱桃归并为过渡种组;岷江冷杉、紫果云杉、铁杉和青扦归并为进展种组.20～40年生的次生林进入以红桦为主的阔叶林阶段,其森林类型分别为藓类-红桦林和箭竹-红桦林;恢复到50年,则开始进入红桦和岷江冷杉组成的针阔混交林阶段, 其森林类型分别为藓类-红桦-岷江冷杉林和箭竹-红桦-岷江冷杉林;未被采伐而保留下来的160～200年生暗针叶林是以岷江冷杉为主的暗针叶老龄林阶段, 其森林类型分别为藓类-岷江冷杉林和箭竹-岷江冷杉林.

By adopting space as a substitute for time, and based on the approaches of inter-specific association, PCA and optimal division, the restoration stages of various secondary forest communities originated from the natural succession processes of bamboo-dark brown coniferous and mossdark brown coniferous old-growth forests after clear-cut were quantified at different temporal series （20, 30, 40, 50 and 160-200 years）. The results showed that Betula albo-sinensis, Salix rehderiana, Acer rnono, A. laxiflorum, Prunus tatsienensis, Hydrangea xanthoneura, Tilia chinensis and Salix dolia were the declining species groups with progressive restoration processes from secondary forest to mature moss and bamboo-dark brown coniferous forests, Sorbus hupehensis, S. koehneana and P. pilosiuscula were the transient species groups, and Abies faxoniana, Picea purpurea, Tsuga chinensis and P. wilsonii were the progressive species groups. During the period of 20-40 years restoration, the secondary forests were dominated by broad-leaved tree species, such as B. albo-sinensis, and the main forest types were moss - B. albo-sinensis forest and bamboo - B. albo-sinensis forest. Through 50 years natural succession, the secondary forests turned into conifer/broad-leaved mixed forest dominated by B. albo-sinensis and A. faxoniana, and the main forest types were moss - B. albo-sinensis - A. faxoniana forest and bamboo - B. albo-sinensis - A. faxoniana forest. The remained 160-200 years old coniferous forests without cutting were dominated by old-growth stage A. faxoniana, and the main forest types were moss- A. faxoniana forest and bamboo- A. faxoniana forest.