草海国家级自然保护区森林群落优势种群数量动态及物种多样性研究

Study on the Quantitative Dynamics and Species Diversity of Dominant Species in Forest Communities in Caohai National Nature Reserve

该研究以草海国家级自然保护区森林群落乔木树种为依据进行聚类分析,将森林划分为4种群落类型,分别为云南松林、云南松-桤木林、桤木-滇杨林、桤木-华山松林。采用空间代替时间的方法,分析不同种群优势树种的年龄结构、存活曲线及静态生命表,应用时间预测模型对4种群落优势树种的发展趋势进行预测,并分析群落物种多样性,为研究区森林保护及可持续经营提供理论依据。结果表明:(1)云南松林和云南松-桤木林优势树种径级结构均呈现偏正态分布,衰退趋势明显,桤木-滇杨林、桤木-华山松林呈偏倒“J”型,衰退趋势相对较弱。(2)静态生命表及存活曲线分析表明,研究区内森林群落不同种群均出现不稳定状态,存活曲线不同程度偏离DeeveyⅢ型曲线。(3)时间序列分析表明研究区内经过未来2、4、6龄级时间后各种群数量出现增加,但中幼龄个体不断减少,老龄个体先增多后减少,如果不加以抚育管理,种群将不可避免走向衰退。(4)研究区内林下共有植物种类35科70属83种,其中灌木层植物17科23属29种,草本层植物21科48属54种。在3种群落类型中,物种丰富度指数(S)为草本层>灌木层,Pielou指数(Jsw)为灌木层>草本层,而桤木-华山松林则呈现相反趋势,物种多样性存在明显差异。

Based on the tree species of forest community in Caohai National Nature Reserve,the forest was divided into four types:Pinus yunnanensis forest,Pinus yunnanensis-Alnus cremastogyne forest,Alnus cremastogyne-Populus yunnanensis forest,Alnus cremastogyne-Pinus armandii forest.The age structure,survival curve and static life table of the dominant tree species in different communities were analyzed by using the method of space instead of time,and the development trend of the dominant tree species in four communities was predicted by using the time prediction model.The species diversity of the community was analyzed to provide theoretical basis for forest protection and sustainable management in the study area.The results showed that:(1)the diameter structure of dominant tree species of Pinus yunnanensis forests and Pinus yunnanensis-Alnus cremastogyne forests showed a partial normal distribution,and the decline trend was obvious,while Alnus cremastogyne-Populus yunnanensis forest and Alnus cremastogyne-Pinus armandii forest showed an inverted“J”type,and the decline trend was relatively weak.(2)The analysis of static life table and survival curve showed that different forest communities in the study area were unstable,and the survival curve deviated from Deevey III curve in different degrees.(3)The time series analysis showed that the number of the population increased after the second,fourth and sixth instars in the study area,but the number of middle and young age individuals decreased,and the number of old age individuals increased first and then decreased,the population will inevitably decline.(4)There are 83 species belonging to 70 genera and 35 families,including 29 species belonging to 23 genera and 17 families of shrub layer and 54 species belonging to 48 genera and 21 families of herb layer.The species richness index(S)was herb layer>shrub layer,and the Pielou index(Jsw)was shrub layer>herb layer in three types of forest community,the Alnus cremastogyne-Pinus armandii forest showed the opposite trend,and there were obvious differences in species diversity.