大兴安岭北坡火后紫貂冬季生境适宜性与景观格局的恢复

Research on Post-fire Restoration of Sable's Habitat Suitability and Landscape Pattern in the Northern Greater Hing′an Mountains

由自然和人为原因引起的生境丧失与生境破碎化已严重影响到野生动物的生存。大兴安岭北坡是国家一级保护动物紫貂(Martes zibellina)的主要分布区,1987年发生在这里的特大森林火灾造成了森林景观的严重破碎化,紫貂的生存面临极大的威胁。本文的研究目的是为了确定火灾13年后,紫貂冬季生境的恢复程度。首先根据紫貂对冬季生境的喜好,选取对其生存影响较大的生态因子,结合数字化林相图,利用地理信息系统软件ArcGIS编制火烧前后的生境适宜性类型图。然后选取相关的景观格局指标,对火烧前后的生境格局进行对比分析。结果显示,尽管火后采取了一系列的森林恢复措施,但紫貂冬季适宜生境仍有大幅度减少,特别是中等适宜生境类型减少最为明显。适宜生境破碎化加剧,隔离度增加。适宜生境斑块的形状趋于简单,软边界比重有所增加。以上结果表明,与火前相比,紫貂生境明显恶化,需要较长的时间恢复。

Habitat loss and fragmentation have been associated with the population decrease of endangered species. A catastrophic fire took place in the northern Greater Hing＇ an Mountains where the main habitat of Sables （ Mattes zibellina） is located in China in 1987. That fire aggravated the loss and fragmentation of the forest landscape inevitably. Due to restricted distribution and low population density, sable has been listed as the national first grade protected species in China. The objective of this paper was to identify to what extent the habitat of sables was restored 13 years later after fire. Based on the behavior data and forest inventory data, suitability habitat maps in winter were derived and habitat structure was analyzed with selected landscape indices. The results showed that compared to the pre-fire situation, although forest cover had mostly restored in 2000, the area of suitable habitat reduced greatly, especially that of the moderately suitable habitat. Fragmentation was aggravated, with suitable patches more isolated. Patch shape became simpler, and the percentage of soft boundaries increased. The results above indicated that the suitable habitat has deteriorated, and much more time is needed for the restoration.