Habitat evaluation of wild Amur tiger (Panthera tigris altaica) and conservation priority setting in north-eastern China

Abstract

The Amur Tiger (Panthera tigris altaica) is one of the world’s most endangered species. Recently, habitat fragmentation, food scarcity and human hunting have drastically reduced the population size and distribution areas of Amur tigers in the wild, leaving them on the verge of extinction. Presently, they are only found in the north-eastern part of China. In this study, we developed a reference framework using methods and technologies of analytic hierarchy process (AHP), remote sensing (RS), geographic information system (GIS), GAP analysis and Natural Break (Jenks) classification to evaluate the habitat and to set the conservation priorities for Amur tigers in eastern areas of Heilongjiang and Jilin Provinces of northeast China. We proposed a Habitat Suitability Index (HSI) incorporating 7 factors covering natural conditions and human disturbance. Based on the HSI values, the suitability was classified into five levels from the most to not suitable. Finally, according to results of GAP analysis, we identified six conservation priorities and designed a conservation landscape incorporating four new nature reserves, enlarging two existing ones, and creating four linkages for Amur tigers in northeast China. The case study showed that the core habitats (the most suitable and highly suitable habitats) identified for Amur tigers covered 35,547 km², accounting for approximately 26.71% of the total study area (1,33,093 km²). However, existing nature reserves protected only (7124 km² or) 20.04% of the identified core habitats. Thus, enlargement of current reserves is necessary and urgent for the tiger’s conservation and restoration. Moreover, the establishment of wildlife corridors linking core habitats will provide an efficient reserve network for tiger conservation to maintain the evolutionary potential of Amur tigers facing environmental changes.

Introduction

Amur tiger (Panthera tigris altaica) is the largest of the five tiger subspecies. They are currently distributed mainly in the eastern mountainous areas of Heilongjiang and Jilin provinces, the Russian Far East and North Korea (Sun et al., 2005). The tiger was ranked as one of the top ten endangered species by the Wildlife Conservation Society in 1994 and was listed as the first-rank protected animal in China. In recent years, habitat degradation and fragmentation, damage to ecosystems, food scarcity, geographical isolation and large scale human hunting have drastically reduced the habitat and number of Amur tigers in the wild, leaving them now on the verge of extinction with a population of only 360–450 individuals (Zhang et al., 2005, Zhou, 2008). They are now in danger of extinction and need immediate protection. Furthermore, being at the top level of the food chain, these animals directly or indirectly control the herbivorous primary consumers and play an extremely important role in the balance of the ecosystem (Li, 2004). This threatened species effectively function as an umbrella species for the remaining mammals (Graham et al., 2003). Recently, many countries have embarked on enlarging nature reserves and linking separate habitats to enhance the survival of tigers, such as the wildlife corridors connecting Heilongjiang province, Jilin province and Russia. Effective protection and management of these eco-corridors are critical in safeguarding and recovering the population of Amur tigers (Sun, 2006). The traditional methods of tiger conservation have included roughly identifying the number of tigers, changes in distribution and the relationship between food density and tiger activity patterns by selecting monitoring areas, establishing monitoring points or monitoring transects (Sun et al., 2005). However, these methods are labor intensive, expensive and are inefficient. With the development of spatial and cyber technologies, remote sensing and geographic information systems provide powerful tools for environmental and habitat assessment on a landscape scale (Store and Jokimäki, 2003, Krivtsov, 2004, Wang et al., 2008). An important feature of remote sensing and geographic information systems is the ability to generate new information by integrating the existing diverse datasets sharing a compatible spatial referencing system (Goodchild, 1993). Recently, these technologies have been used for gathering information on physical parameters of wildlife habitats, geospatial modeling for wildlife habitat evaluation and nature reserve design (Huang et al., 1998, Kushwaha and Roy, 2002). Use of these technologies provides for more effective data collection and analysis enhancing the protection of Amur tigers.

Previous landscape level analyses of tiger distributions using modern technologies have identified parts of Northeast China as priority areas for tiger conservation (Sanderson et al., 2006). The current study takes a closer look at the already identified priority areas, examining factors that might influence their distribution at the local level, and identifying core habitats and linkages within the tiger conservation landscape.

An important aspect in species conservation is habitat protection, which is defined as the necessary living units for a given wild species, including space, food, water, etc. Habitat suitability models are useful habitat evaluation tools that have been extensively used by conservation planners to estimate the likelihood of occurrence and abundance of threatened wildlife species in terrestrial ecosystems (Carvalho and Gomes, 2003). Based on the extensive data collected, we developed a habitat suitability model incorporating vegetation types, food density, topography (elevation, slope and aspect) and human disturbance (human population density and distance from roads) as effective factors to evaluate tiger habitat. Then we conducted a GAP analysis by comparing the results with the pattern of existing reserves, prioritized the conservation gaps for on-ground implementation and finally put forward suggestions for conservation planning (Scott et al., 1993, Prendergast et al., 1999).

The methods and technologies used in the study were remote sensing (RS), geographic information system (GIS), analytic hierarchy process (AHP) and Natural Break (Jenks) classification. A Habitat Suitability model was developed using these methods and technologies to identify suitable sites and conservation priorities for Amur tigers in the study area. In this paper, we aim to provide the scientific basis and references for effective habitat evaluation, priority setting and conservation planning for the Amur tiger.