辽东林区人工诱导红松阔叶混交林群落结构与动态变化

Structure and Dynamic Change of Artificially Induced Korean Pine and Broad-leaved Mixed Forests in the Eastern Forest Region of Liaoning Province

采用样带网格调查法和分层株数法,初步研究了辽东林区退化天然次生林经40余年人工诱导形成的红松阔叶混交林群落结构及动态变化趋势,定量地评价了不同恢复措施对其群落结构及动态的影响,探讨了辽东林区退化天然林恢复技术及优化模式。结果表明:不同透光方式(未透光、半透光和全透光)对群落组成结构和径级分布具有较大的影响,即随着透光强度的增加,红松在群落中的地位(重要值依次为49.3%、75.8%和100.0%)呈现出逐渐加强的变化规律,而阔叶树种则逐渐下降;未透光林分以中、小径材占优势(94.8%),半透光林分以中径材占优势(88.9%),而全透光林分则以大、中径材占优势(100%)。立地条件(坡位)对群落结构也具有一定的影响,即沿着自下而上的坡面环境梯度,半透光林分中红松的重要值在中上部坡位呈现增加趋势(61.5%、74.5%和75.8%),阔叶树种呈现出有规律的更替;半透光林分大径材比例呈下降趋势;全透光林分的中径材质量有所下降。半透光林分与全透光林分均呈现出更新层和演替层数量较多,主林层数量较少的分布格局,且均呈现出进展演替趋势——红松阔叶混交林。

An experiment was conducted to study the structure and dynamic change of artificially induced Korean pine and broadleaved mixed forests from degraded natural secondary forests for the past 40 years by line transect method and tree counting method for each divided stratum in the eastern forest region of Liaoning. The effects of different restoration methods on their structure and dynamic change were assessed quantitatively, and the restoration techniques and the optimal mode were discussed. Results showed that different tending and thinning measures （control, selective cutting in the upper layer, and clear cutting in the upper layer） had great influence on species composition structure and diameter class distribution of the community, namely, the important value of Korean pine in the community gradually increased （49.3%, 75.8% and 100.0% respectively） as tending and thinning intensity increasing, while the broad-leaved trees showed an opposite trend. Medium diameter trees and small diameter trees were dominant in the control（94.8% ） , and medium diameter trees was dominant in the upper layer in the selective cutting stand（88.9% ） , but large diameter trees and medium diameter trees were dominant in the upper layer in the clear cutting stand（ 100% ）. The site （ slope position） also had certain influence on community structure, the important value of Korean pine increased from the lower slope position to the upper slope position（61.5%, 74.5% and 75.8% respectively）, and the broad-leaved trees showed regular succession. Moreover, the proportion of large diameter trees decreased in the upper layer in the selective cutting stand. The quality of medium diameter trees declined in the upper layer in the clear cutting stand. Selective cutting stand and clear cutting stand in the upper layer showed the same distribu- tion pattern： the number of tree species in regeneration layer and succession layer was much more than that of tree layer, and they would both be developing to the stage of Korean pine and broad-leaved mixed forest.