内蒙古自治区西部山地沙被空间格局及其植被调查

Spatial Pattern and Vegetation Characteristics of Mountain Sand Cover in Western Inner Mongolia

内蒙古西部区山地广泛分布着沙被景观,但目前学者们对于山地沙被的研究还相对较少,对山地沙被的动态、特性、功能和空间格局也还认识不足。文章采用卫星遥感和实地考察相结合的方法,对分布于内蒙古西部贺兰山、狼山和雅布赖山的山地沙被空间格局、斑块数量和植物群落特征等进行了普查和分析。结果表明:贺兰山、狼山和雅布赖山山地沙被覆盖比分别为4.68%、10.61%和24.40%,表现为越接近较大规模沙漠,山地沙被的覆盖比越大。大多数山地沙被与上游沙源地沙漠间存在地表沙被连续性,在距上游沙源地较近处的山坡、沟谷分布较多;距上游沙源地相对较远处,山地沙被具有在山谷集中分布且在相对宽阔的沟谷堆积的格局;仅有少量山地沙被呈孤岛状存在于山地基岩之上。从空间连通性上看,山地有效阻碍了沙物质向东南方向的移动;但有些区域的上游沙物质已覆被到了山谷和山坡,形成了特殊的山地沙被景观,有些区域的沙被甚至翻越了整个山地,构成了两大沙漠间的连接带。另外,山地沙被空间分布范围在年代际尺度上相对稳定。从气候和植被的角度看,贺兰山、狼山西段、雅布赖山的山地沙被属于沙漠性质,狼山东段及中段的山地沙被属于沙地性质。山地沙被上的植物群落具有沙被植物群落和山地砾化山坡植物群落的双重特征,但更倾向于沙被植物群落类型。研究结果可为内蒙古西部贺兰山、狼山和雅布赖山的生态保护、修复、开发利用和灾害防御提供理论依据。

Sand cover landscape is widely distributed in the mountainous areas of western Inner Mongolia, but there are relatively few researches on mountain sand cover, and the dynamics, characteristics, functions and spatial pattern of mountain sand cover are also not well understood. In this article, the spatial pattern, patch quantity and characteristics of plant communities in Wolf Mountain, Helan Mountain and Yabulai Mountain in western Inner Mongolia were investigated and analyzed by means of satellite remote sensing and field investigation. The results showed that the coverage ratios of mountain sand cover of Helan Mountain,Wolf Mountain and Yabulai Mountain were 4.68%, 10.61% and 24.40%, respectively. The closer to the large desert, the greater the sand coverage ratio. There was continuity between most of the mountain sand cover and the upstream sand source region. The mountain sand cover was more distributed on hillsides and valleys near the upstream sand source. At a relatively far distance from the upstream source area, the mountain sand cover was concentrated in the valleys and accumulated in the relatively wide gullies,and only a small amount of mountain sand cover existed as leaping island on the top of mountain bedrocks. From the perspective of spatial connectivity, the mountains effectively obstructed the movement of sand to the southeast. However, in some areas, the sand of upstream region had been covered to valleys and hillsides, forming a special mountain sand cover landscape. In some other areas, the sand cover had been over the entire mountain, forming a link between two deserts. In addition, the spatial distribution of mountain sand cover was relatively stable on the interdecadal scale. From the perspective of climate and vegetation, mountain sand covers in Helan Mountain, the west side of Wolf Mountain and Yabulai Mountain were desert, the mountain sand cover in the east and middle areas of the Wolf Mountain was sandy land. The plant communities on mountain sand cover had double characteristics of sand cover plant communities and gravelly mountain slope plant communities, but they were more close to the types of sand cover plant communities. The results could provide theoretical basis for ecological protection, restoration, exploitation and disaster prevention in Helan Mountain, Wolf Mountain and Yabulai Mountain in western Inner Mongolia.