短花针茅荒漠草原不同载畜率植物群落优势种群空间分布格局的研究

Study on Spatial Distribution Pattern of Dominant Populations in Plant Community with Different Stocking Rates in Stipa breviflora Desert Steppe

以内蒙古四子王旗短花针茅荒漠草原为研究对象,应用扩散系数的t检验、平均拥挤度、丛生指标、聚块性指标、Green指数、Cassie指标等方法,研究了短花针茅、无芒隐子草和冷蒿3种优势植物在不同载畜率下的格局分布类型、格局规模以及聚集强度。结果表明,短花针茅、无芒隐子草和冷蒿的分布类型均为聚集分布,其中,在对照区和中牧区,其聚集强度的大小顺序依次为无芒隐子草、冷蒿、短花针茅;在轻牧区和重牧区,聚集强度的大小顺序依次为冷蒿、无芒隐子草、短花针茅。随着草地的退化,无芒隐子草和冷蒿在群落中上升为主要的种群。

With the Stipa breviflora desert steppe in Siziwang Banner of Inner Mongolia as the research object, the pattern distribution types, pattern scale and clump intensity of 3 kinds of dominant plants as S. breviflora, Cleistogenes mutica, A rtemisiafrigida with different stocking rates were studied by using t test of diffusion coefficient, mean crowding intensity, clumping index, patchiness index, Green index, Cassie index and so on. The results showed that the distribution types of S. breviflora, C. mutica, A. frigida were clump distribution. In CK area and middle pasturing area the clump intensity of 3 kinds of plant in order was C. mutica 〉 A. frigida 〉 S. breviflora and in light and heavy pasturing area, their clump intensity in order was A. frigida 〉 C. mutica 〉 S. breviflora. With the degradation of desert steppe, C. mutica and A. frigida would become as the main populations in community.