古浪县北部荒漠植被主要植物种的生态位特征

利用Shannon-Wiener生态位宽度公式和Pianka生态位重叠公式,计测分析了甘肃省古浪县北部荒漠植被主要植物种在不同植被演替阶段的生态位宽度和生态位重叠。结果表明:在流动沙地上花棒的生态位宽度最大,其次是沙蒿;在半固定沙地上白刺的生态位宽度最大;在固定沙地上,不论是封育植被还是未封育植被中均是花棒的生态位最宽。同一植物种的生态位随着植被演替阶段的变化而发生变化,这种变化反映了不同演替阶段下的植被恢复效果。优势种的生态位重叠大,生态位宽的物种对重叠值也大,相同物种对在不同演替阶段的生态位重叠不一致。有些物种生态位宽度窄,但重叠值大,是由荒漠植被区物种分布存在生境斑块现象造成的。

Niche characteristics of main plant species in desert areas of north Gulang County, Gansu Province

By using Shannon-Wiener index of niche breadth and Pianka index of niche overlap, this paper studied the niche characteristics of main plant species at different succession stages of vegetation in desert areas of north Gulang County, Gansu Province. The results showed that on mobile sand, Hedysarum scoparium had the widest niche breadth, followed by Artemisia arenaria. On semi-fixed sand, Nitraria tangutorum had the widest niche breadth, while on fixed sand, whether on unclosing fixed sand or on closing fixed sand, the niche breadth of H. scoparium was the widest. The niche breadth of the same plant species varied with vegetation succession stage, which reflected the effect of restored vegetation under different succession stages. Dominant species and the species with wide niche breadth had large niche overlap, while the niche overlaps of the same pair of species at different vegetation succession stages were inconsistent. Because of the habitat patch of species distribution, some species with narrow niche breadth also had large niche overlap.