放牧对甘肃多儿保护区大熊猫小种群形成的驱动探讨

小种群是在自然因素或人为活动影响下，形成具有生存风险的隔离或异质种群，认识其形成原因并制定保护对策是开展救护行动的基础。野生大熊猫(Ailuropoda melanoleuca)具有许多相互隔离的小种群，各小种群的生存状况决定该物种的整体保护成效。本文以甘肃多儿保护区大熊猫种群为例，在对保护区内大熊猫进行种群分布、空间利用、干扰状况调查的基础上，开展栖息地适宜性评价，分析了保护区大熊猫有效利用空间及其时空格局与环境容纳量。结果显示：(1)保护区适宜栖息地面积5 789.2 hm²，次适宜栖息地面积18 165.6 hm²，共占保护区总面积43.9%。优质栖息地主要分布在工布龙区域，该区域森林和生态系统保持原生状态，也是保护区大熊猫的主要分布区；(2)工布龙区域总面积9 949.7 hm²，其中适宜和次适宜栖息地共5 129.4 hm²，牧场是大熊猫栖息地的主要干扰因子，放牧干扰下工布龙区域适宜和次适宜栖息地面积共减少12.9%，破碎化水平加剧；(3)牧场与大熊猫栖息地镶嵌分布，导致适宜栖息地隔离，放...

A Study on the Driving Effect of Grazing on Giant Panda Small Population Formation in Gansu Duoer Reserve

Objectives] Small populations are isolated or heterogeneous populations with survival risks under the influence of natural factors or anthropogenic activities, and understanding their formation are the basis to formulate conservation strategy and rescue programme. The Giant Panda (Ailuropoda melanoleuca) has many small populations which are isolated from each other, and the living conditions of the small populations will determine the overall conservation effectiveness of the species. Methods] Taking the Giant Panda population in Duoer Reserve of Gansu Province as an example (Fig. 1), based on the investigation of population distribution, space utilization and disturbance status of the Giant Panda in the reserve, the habitat suitability assessment was completed, and the spatial and temporal pattern of effective utilization of the Giant Panda and its environmental capacity are also analyzed (Table 1). Results] The results showed that: (1) The suitable habitat area of the reserve is 5 789.2 hm2, and the sub-suitable habitat area is 18 165.6 hm2, accounting for 43.9% of the total area of the reserve (Table 2). The high-quality habitat is mainly distributed in Gongbulong area, which is the main distribution area of Giant Pandas in the reserve (Fig. 2). (2) Grazing is the main disturbance factor of Giant Panda habitat in the Gongbulong area, and the pasture occupies 43.7% of this area. The total area of suitable and sub-suitable habitats in the Gongbulong area decreased by 1 200.9 hm2 under grazing interference, accounting for a decrease of 12.9% in the total area of the region (Fig. 3, Table 3); moreover, the fragmentation of habitat got worse. (3) Pasture inserted into Giant Panda habitat and shaped mosaic pattern with habitat, it also led to the isolation of suitable habitat. Due to the seasonal features for grazing, Giant Pandas were forced to choose seasonal migration along altitude retrograde to avoid the interference, which resulted in a suitable habitat area of 364.0 hm2 available for their use, sub-suitable habitat area is 1 088.9 hm2 in summer, and the available suitable habitats are 756.4 hm2 and the sub-suitable habitat area is 1 719.2 hm2 in winter and spring (Table 4). Conclusion] Studies have shown that the spatial pattern of pastures and grazing activities lead to insufficiency of living space and habitat isolation for Giant Pandas. Especially in summer, the minimum environmental capacity is only 2 to 3, which cannot guarantee the long-term survival of large populations. It also affects their life history and population fitness resulting in a low encounter rate in field. It is suggested to optimize the functional zoning, adjust the pasture layout, control the grazing activities to reduce the disturbance and increase the habitat supply, and implement Ex-situ conservation programme to improve the habitat environment and living conditions of the small population.