新疆伊犁荒漠草原恢复措施下植物群落生态位特征分析

以禁牧2 年、休牧(每年5 月底至10 月初)、补播杂花苜蓿2 年3 种恢复措施及处于自由放牧状态下的荒漠草原退化草地为研究对象, 分析了伊犁荒漠草原植物群落的生态位特征。结果表明: 在对照、禁牧、休牧样地中, 建群种伊犁绢蒿(Seriphidium transiliense)生态位宽度值最大, 分别为1.037、1.101 和1.070, 在补播样地中针茅(Stipa sp.)的生态位宽度值最大, 为0.798。较高的生态位重叠发生在生态位宽度较大的物种之间,但最大的生态位重叠发生在生态位宽度较小的物种之间。在4 种样地中, 伊犁绢蒿-角果藜(Ceratoides arenarius)之间存在较高的生态位重叠和较大的生态位相似比例, 证明2 个种群之间在资源利用上存在激烈的种间竞争。

Characteristics of plant niche under different restoration measures in Ili desert grassland of Xinjiang Uygur Autonomous Region

Serious degradation of spring and autumn sagebrush desert steppes was a bottleneck for developing seasonal animal husbandry in northern Xinjiang. In order to restore the sagebrush desert steppes, grazing was seasonally banned or long-term prohibited and grassland reseeding was adopted. In this study, the characteristics of niche breadth and niche overlap of 16 Ili desert grassland species were analyzed. The selected grasslands were seasonal grazing banned, long-term grazing prohibited, reseeded and grazed freely. The dominant species (Seriphidium transiliense) had the largest niche breadth, expect in reseeded grassland. S. transiliense niche breadths in freely grazed grassland, long-term grazing prohibited grassland, seasonally grazing banned grassland were 1.037, 1.101 and 1.070, respectively. In also the reseeded grassland, Stipa sp. had the largest niche breadth (0.798). While higher Pianka niche overlap occurred in high niche breadth species, the highest niche overlap occurred in low niche breadth species. Furthermore, niche proportion similarity and overlap between S. transiliense and Ceratoides arenarius were high in all four grasslands. This showed an intense interspecies competition for resources between the two species.