The Siberian tiger (also known as the Amur tiger) is one of the most critically endangered species in the world, and a keystone species in the Eurasian Temperate Forests of northeastern China and Russia Far East. Before the 20th century, the Siberian tiger was found in Russia Far East, Northeastern China, Eastern Mongolia, and the Korean peninsula, with a total number of more than 3000. Recent surveys indicate that the current tiger population consists of fewer than 600 individuals. The distribution areas are now restricted to one large habitat patch and two smaller ones in Russia Far East, and a few scattered small patches in northeastern China near the Russia-China border. Is the Siberian tiger population viable in a long run? How do habitat loss and fragmentation affect the population viability of the tigers? What conservation measures are needed to improve the population viability of the tigers? In this study, we address these questions using a population viability analysis approach in combination of spatial analysis with empirical data on habitat pattern and historical population dynamics of the tiger.
Our results show that poaching has been the most direct and significant threat to the Siberian tiger’s survival. The loss, fragmentation, and deteriorated quality of habitat also have had serious effects on the population viability of the tigers. The effects of habitat fragmentation varied as the total area of habitat changed. While tiger subpopulations persisted longer with increasing size of habitat patches, the detail of spatial configuration of habitat did matter significantly to the long-term viability of the entire tiger population. In particular, regional-level habitat connectivity was key to the tiger population viability for a given total area of habitat, pointing to the importance of establishing movement corridors in reserve design for the Siberian tiger. Based on our simulation analysis, we suggest to establish corridors between reserves in Russia and China to link the fragmented tiger habitats. Our results show that such cross-border corridors were essential for the long-term survival of the Siberian tiger. In addition, our study provides useful information for landscape planning and sustainable development in this region.