sapling forest

At the same time, with the large sapling forest ecosystem is for the research object, bring up the concept of key species that with related the degree of harm sapling, and the calculation formula of key species index and distinguish the standard.

同时，以幼林生态系统为研究对象，提出了与林木危害程度相关的群落关键种的概念以及关键种指数的计算公式和判别标准。

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Research on Soil and water loss law of newly built sapling forest land of Pinus elliottii

湿地松新造幼林地水土流失规律研究

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The two differ, Luan of the first month forest farm forest more class, while the black dragon hill forest birch sapling forest maximum diameter is 9, and the tree numbers less.

两地不同之处在于，孟滦林场大阶级林木较多，而黑龙山林场白桦幼龄林最大径阶为9，且林木株数较少。

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Black dragon hill forest birch sapling forest aggregation degree than Luan of the first month forest birch sapling forest aggregation degree is bigger.

黑龙山林场白桦幼龄林聚集程度比孟滦林场白桦幼龄林聚集程度较大。

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Point out the community key species is species that result in serious impaired forest, its density with the constitute ratio and the degree of harm sapling is related.

指出群落关键种的实质是对林木造成严重危害的种群，其密度和组成比与林木的被害程度呈正相关。

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