极小种群东北红豆杉所在群落特征及其环境解释

以东北红豆杉(Taxus cuspidata Sieb.et Zucc.)所在群落为对象,选择有东北红豆杉分布的21个样方进行群落调查,结合样方植物和环境数据,采用系统聚类、RDA分析、方差分解等方法研究东北红豆杉所在群落的特征及其主要影响因素。结果表明:(1)东北红豆杉所在群落共记录到48科90属107种植物,其物种组成丰富,可将群落划分为红松-紫椴林、红松-云杉-冷杉林、红松-槭树林、红松-风桦林4个林分类型;(2)温度、降水、林分类型和土壤pH等环境因子显著影响东北红豆杉的分布及其群落特征,整体上温度是最显著的影响因子,但在不同林型中各环境因子的主要作用不同;(3)气候因子、地形与土壤因子、生物因子三者对东北红豆杉所在群落分布的共同解释率为49.85%,地形与土壤因子的单独解释力最大(15.70%),其次为气候因子(14.96%)和生物因子(9.79%)。总之,由于自然和人为因素的干扰,东北红豆杉所处的群落类型多样,且东北红豆杉种群特征在不同的群落中各不相同,主要分布在红松-紫椴林和红松-云杉-冷杉林中,其他2种群落类型对回归保护地的选择具有很好的指示作用,应针对不同的分布群落采取不同的保护措施。

Characteristics and environmental interpretation of communities of Taxus cuspidata Sieb. et Zucc., a plant species with extremely small populations

In this paper, the Taxus cuspidata Sieb. et Zucc. community was taken as a breakthrough point, and 21 plots with Taxus cuspidata distribution were selected for community survey. From the sampled plant and environmental data, the characteristics and main influencing factors of Taxus cuspidata communities were studied by systematic clustering, RDA analysis, and variance decomposition. Results showed that: (1) A total of 107 species belonging to 90 genera and 48 families were recorded, and Taxus cuspidata communities exhibited high species richness. The Taxus cuspidata communities could be divided into four types: i.e., Pinus koraiensis-Tilia amurensis forest, Pinus koraiensis-Picea jezoensis-Abies nephrolepis forest, Pinus koraiensis-Acer forest, and Pinus koraiensis-Betula costata forest. (2) Temperature, precipitation, forest type, and soil pH significantly affected species composition of the Taxus cuspidata communities, with overall temperature being the most significant factor.However, the main effects of environmental factors in different forest types were different. (3) Climatic, topographic, soil, and biological factors jointly explained 49.85% of Taxus cuspidata community distribution. Among the above factors, topographic and soil factors had the largest individual explanatory power (15.70%), followed by climatic (14.96%) and biological factors (9.79%). In conclusion, due to both natural and human interference, the Taxus cuspidata communities are diverse, and the population characteristics of Taxus cuspidata is different among the communities. Taxus cuspidata is mainly distributed in Pinus koraiensis-Tilia amurensis and Pinus koraiensis-Picea jezoensis-Abies nephrolepis forests, and the other two community types have a guiding significance for Taxus cuspidata reintroduction protection. In addition, different protection measures should be considered for the different community types.