大渡河干旱河谷四川牡丹种群结构特征及与环境因子的关系

摘要

2014年对四川省阿坝州四川牡丹分布较为集中的地方设置19个样方进行调查,根据其数据编制静态生命表,采用主成分分析等方法对大渡河干旱河谷四川牡丹种群结构、种群特征与环境因子的关系进行研究.结果表明,不同生境的四川牡丹种群年龄级分布存在一定差异,在以灌木为优势种的群落生境中,由于郁闭度低、透光率高,四川牡丹幼苗数量多,种群的更新状态较好,属于增长型或稳定型种群;在以乔木为优势种的群落生境中,四川牡丹幼苗死亡率高,种群属于衰退型;主成分分析表明,四川牡丹平均基径和种群密度受环境因子影响显著,其中坡度是影响四川牡丹种群特征的首要环境因子,其次是土壤自然含水率.%Investigations were implemented in 2014 on 19 samples plots of Paeonia szechuanica communities relatively more distributed in Aba, Sichuan province. Static life table was compiled based on survey data. Relationship of population structure and properties with environmental factors was analyzed by principal component analysis.The results showed that age class distribution of P. szechuanicapopulation had difference among different sample plots. At habitats dominated by bush species,P. szechuanicahad more seedlings, indicating better regeneration and belonging to stable and growing population. At habitats dominated by tree species,P. szechuanica had higher death rate of seedlings, indicating declining population. Principal component analysis showed that the average ground diameter and population density ofP. szechuanica was significantly affected by environmental factors, especially slope and soil moisture content.