| With millions of years of evolution,the Siberian tiger is at the top of the food chain and plays an important role in the natural ecosystem,reflecting to some degree the regional biodiversity and function of natural ecosystem.However,the Siberian tiger is one of the most endangered species both nationally and internationally.Based on the historic changes in Siberian tiger distribution and number,the dynamic changes in the land use in the distribution area/vegetation coverage,and the study on the driving forces that brought about these changes,helped by previous researches,surveys of sample plot inventory,3D space data collecting,processing,analyzing,this article,conducts analysis of current Siberian tiger distribution area and suitability assessment by using AHP,and selects potentially restorable Siberian tiger habitat by using resource function model(space logistic regression model),and analysis the connection among each potential habitat to pick up protection corridors by the theory of landscape ecology and landscape connectivity.The main conclusions are as follows:(1)Siberian tigers fell sharply in number,to their extinction,with their habitat shrinking into fragments.But at present it turns for the better.Tigers are unevenly distributed in the middle and south of Sikhote-Alin in Russia and in 6 isolate areas in China such as the south of Old Master Peak,the east of Wanda Mountains,Ragon Ridge,the north of Old Master Peak,Harba Peak,the south of Zhangguangcai Peak.The number of tigers in the far east of Russia is about 500.In the early decades of 20 th century,the number of tigers had a tendency toward sharp decline in China.Wild Siberian tigers are now experiencing a slight rise in China,there are 11-13 wild Siberian tigers in the monitored areas in Jilin Province,12-14 in Heilongjiang Province in 2013.(2)Due to extensive land reclamation,large-area deforestation,significant changes had occurred in land use and land cover types in Siberian tiger distribution area.Before1860,human land use activities caused little disturbance on the natural ecological environment.After 1860,China and Russia encouraged large numbers of immigrants to exploit the resources in the areas,which resulted in the landscapes fragmentation,and tiger habitats shrink.At present,the degree of the land use intensity in China is fargreater than that in Russia Far East Area.Russia's overall forest coverage is greater,and forest quality is better.From 1980 to 2015,the area of mixed forest which is optimum for Amur tiger distribution has increased by 36.48 km2 in China'Amur tiger distribution area;the area of bare vegetation cover where Siberian tigers avoid has increased 70.83km2,with an annual increasing rate of 0.94%;Farmland area has increased by 478.4km2,with an annual increasing rate of 0.33%;the wetland water area which plays an important regulatory role on areal climate has increased by 27.42 km2,Amur tiger habitats tend to be better off.(3)The research on the suitability of the habitat in the current Siberian tiger distribution areas shows: the areas most suitable for tigers cover 37.59% of tiger distribution areas,located in Ragon ridge,the south of Old Master Peak,the north of Old Master Peak,Wanda Mountains: the suitable 28.68% in Wanda Mountains,the south of Old Master Peak,the north of Old Master Peak,Harba Peak,the south of Zhangguangcai Peak in Jilin Province: the less suitable 25.03% in Zhangguangcai Peak in Jilin Province and Heilongjiang Province,Harba Peak,Wanda Mountains,Old Master Peak: the unsuitable areas,which,small in size,but significant,cover 8.70% of the tiger distribution area,equivalent to 3949.39 km2,is situated in the north of Zhangguangcai Peak in both Jilin and Heilongjiang Province.The unsuitable areas are also found in 4 of the other 5 isolated tiger distribution areas.Tigers will be put in a position unfavorable for their existence and for them to forage food when these isolated area reach a certain size.(4)The research on wild Siberian tiger potential habitat selection and assessment shows: by calculating the constructed logistic potential habitat statistical model,and using probability ARCGIS natural breaks,the study areas are divided into unsuitable,less suitable,suitable and the most suitable by calculating on the constructed Logistic potential habitat model.The Amur tiger's is better relatively suitable habitat area and,most suitable habitat area areis 73148 km2 and 73740 km2 respectively,accounting for5.62% and 5.62% of total area and 5.62% respectively;Mid-range suitable habitat area is 164824 km2,accounting for 12.67% of the total area;not suitable habitat area is989032 km2,accounting for 76.04% of the total area,which is the largest proportion,much of the study area is not suitable for Amur tiger's survival.Suitability is high among the current Siberian tiger distribution area such as the east of Wanda Mountains,the west of Wanda Mountains,the north of Old Master Peak,the south of Old Master Peak,the south of Zhangguangcai Peak,Ragon Ridge and Harba Peak.The north of Zhangguangcai Peak and Lesser Khingan Mountains area,as historic distribution areas,is rather suitable.(5)The research on the construction of the Siberian tiger habitat corridors and their habitat protection use the cost method of the GIS program ARCGIS10.1 to Siberian tiger diffusion accumulative cost DRG.Based on this accumulative cost DRG,we designate preferable sanctuaries and the potential corridors among adjacent preferable Siberian tiger sanctuaries,which paved the way for future Siberian tiger diffusion.To put it in a few words,this article,covers the natural course of the endangerment of Siberian tigers,and exploits the relation between the number and habitat of Siberian tigers,and conducts a basic research on the integration of the isolated habitats and habitat protection,and lays the scientific foundation for a wild Siberian tigers protection scheme,and is significant in sustaining the existence of Siberian tigers and biodiversity. |
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