以放牧率梯度研究内蒙古典型草原主要植物种群的生态位

对内蒙古典型草原主要植物种群在不同放牧强度下生态位分化规律进行研究。结果表明，羊草，克氏针茅的生态位，宽度相对较窄，分别为０．２９８和０．５６５，表明对放牧较敏感，属宜轻牧植物。蓿豆，冰草和菊叶委陵菜的生态位宽度适中，属宜中牧植物。而糙隐子草，冷蒿，星毛委陵菜，雨草苔，木地肤和变蒿等耐牧性较强，具有很宽的生态位宽度分别为０．９７８，０．９６９，０．９３１，０．９７０，０．９３８，０．９２４，具有很

Responses of the Major Plant Populations of Inner Mongolia Typical Steppe to Grazing Rate Based on Niche Considerations

On the grazing gradient consisting of six different stocking rates,niche breadths and niche overlaps for 11 main plant populations in Inner Mongolia typicaI steppe were measured,and the following results wcre concluded: 1)Leymus chinensis and Stipa grandis had relatively narrow niche breadths (0.298,0.565)and could endure only light grazing. While Agropyron michnoi, Potentilla tauacetifolia,and Melissitus rulhenica had intermediate niche breadths (0.857, 0.891, 0.849),which could endure moderate grazing intensity. 2)Cleistogenes squarrosa, Potentilla acaulis .Carex duriuscula,Artemisia frigida, Kochia prostrata,Artemisia commutata had extremely wide niche breadths(being0. 978,0. 931,0. 970,0.969,0.939,0. 924respectively). These species could endure heavy grazing intensity,showing considerable ability in utilizing resources. 3) It could be seen that the species with greater niche breadths generally had greater niche overlaps with other species,and the niche overlaps among species that had similar morphological characters were much greater.