东北地区天然次生林乔木层物种多样性与树木生长的关系

Relationship between species diversity of arbor layer and tree growth in natural secondary forests in northeast China

【目的】了解东北地区天然次生林乔木层物种多样性和树木生长之间的关系,确定合理的物种多样性大小,进行适当的抚育采伐和人工补植,为次生林经营与管理提供科学的理论基础。【方法】在东北小兴安岭(XXAL)、张广才岭(ZGCL)、老爷岭(LYL)、长白山(CBS)、哈达岭(HDL)和龙岗山(LGS)地区共设置样地123块,调查各地区物种组成、重要值、多样性和树木生长情况。【结果】所有样地内共调查物种48种,隶属于17科31属,其中龙岗山地区样地内所包含的科、属、种数量最多,其次为哈达岭、长白山、老爷岭、张广才岭和小兴安岭,从重要值看,各地区主要以榆树、色木槭和水曲柳为优势树种;样地内物种α多样性指数均在长白山地区表现最大,在小兴安岭地区表现最小,且两者之间差异性显著(P<0.05),丰富度指数则在龙岗山最大,在小兴安岭最小,两者之间差异性显著(P<0.05),而各地区之间纬度相差越大,样地内物种β多样性指数差异越明显,两地之间物种共有种越少,群落演替速率越高;各地区平均胸径和平均树高大小关系均表现为CBS>LYL>LGS>ZGCL>HDL>XXAL,各地区胸径最大树种为长白山地区蒙古栎,胸径为64.8 cm,胸径最小树种为龙岗山地区暴马丁香,胸径为4.0 cm,各地区树高最大物种为龙岗山地区胡桃楸,树高为28.9 m,树高最小树种为龙岗山地区黄菠萝,树高为1.3 m。【结论】在一定范围内,物种多样性对于林分内物种平均胸径和平均树高均有促进作用。因此,在次生林经营管理过程中,应采取适当的抚育采伐和人工补植,保证合理的林分物种多样性,为天然次生林的生长提供最优的空间。

【Objective】Through understanding the relationship between species diversity of arbor layer and tree growth in natural secondary forests in the Northeast,China,to determine the reasonable size of species diversity and carry out appropriate tending and artificial replanting,and then provide a scientific theoretical basis for the management of secondary forests.【Method】A total of 123 plots were set up in the Xiaoxing’an ridge(XXAL),Zhangguangcai ridge(ZGCL),Laoye Ridge(LYL),Changbai mountain(CBS),Hada ridge(HDL)and Longgang mountain(LGS)to investigate the species composition,Important value,diversity and tree growth in this study.【Result】A total of 48 species were investigated in all plots,belonging to 17 families and 31 genera,among them,the number of families,genera,and species included in the Longgang mountain plots was the largest,followed by Hada ridge,Changbai mountain,Laoye ridge,Zhangguangcai ridge,and Xiaoxing’an ridge.Judging from the important values,the Ulmus pumila,Acer mono and Fraxinus mandshurica were dominant species in each region.Theαdiversity index of the species in the plots was the largest in the Changbai mountain area and the smallest in the Xiaoxing’an ridge area,and the difference between the two was significant(P<0.05).The richness index was the largest in Longgang mountain and the smallest in Xiaoxing’an Ridge,and the difference between the two was significant(P<0.05).The greater the latitude difference among areas,the more obvious the speciesβdiversity index difference in the plot,and there were the fewest common species in the two araes and the highest community succession rate.The relationship among the average DBH and the average tree height in each region was CBS>LYL>LGS>ZGCL>HDL>XXAL.The tree with the largest diameter at breast height(DBH)and the smallest DBH in each region were Quercus mongolica in Changbai Mountain and Syringa reticulata in Zhangguangcai Ridge,with a DBH of 64.8 cm and 4.0 cm respectively.And the tree with the largest height and the smallest height in each region were J.mandshurica in Longgang mountain and Phellodendron amurense in Longgang mountain,with a DBH of 28.9 m and 1.3 m respectively.【Conclusion】Within a certain range,species diversity had a promoting effect on the average DBH and average tree height of the species in the forest.Therefore,in the process of secondary forest management,proper tending and artificial replanting should be adopted to ensure reasonable forest species diversity and provide the best space for the growth of natural secondary forests.