土壤水分对中国沙棘人工林结构多样性的影响

为揭示土壤水分对中国沙棘人工林分化的影响规律，采用物种多样性指数分析了不同坡向12年生林分的结构多样性。结果表明，土壤含水率按照北、西、东、南坡向依次递减，且不同坡向间存在极显著差异；种群生长量、密度与土壤含水率相关显著；随着土壤水分的改变，种群生长、繁殖能力以及种群间和种群内的分化、综合优势比随之改变。随着土壤含水率的降低，林分的密度逐渐变小、离散程度加大、郁闭度逐渐降低、更新速度减缓，土壤水分引起的变异占总变异的50.26％，从而形成了多样性的种群结构。

Effect of Moisture on the Structural Diversity of Hippophae rhamnoides L.subsp.sinensis Plantations

In order to study the effects of soil moisture on differentiation of Hippophae rhamnoides L.subsp.sinensis plantations, 12 years old plantations located at different slopes were chosen to analyze the species diversity indexes . The results indicated that in the order of north , west, east and south slope , the soil moisture showed the change of decrease , and the differences between slopes were very significant .Both population growth and population density were significantly correlated with soil moisture .As the soil moisture changed , the population growth , reproductive capacity , differentiation among or within populations , and summed dominance ratio changed accordingly .With the decrease of soil moisture , the stand density gradually decrease , dispersion degree increase , canopy density de-crease, regeneration speed decrease .The study results revealed that the variation caused by soil moisture change accounted for 50.26 % of the total variation , the diversified population structure therefore formed .