Dynamics of Suitability and Conservation of the Black-Necked Crane Habitats in the Midstream of the Yarlung Zangbo River

Aiming at the restraining factors of and the main threats to suitability of the black-necked crane habitats in the Black-necked Cranes National Nature Reserve in the valley of the mid-stream of the Yarlung Zangbo River, based on the indices, such as habitat suitability, conservation ratio, conservation efficiency and so on, suitability and conservation status of the black-necked crane habitats at their third stage in Shigatse, the Black-necked Cranes National Nature Reserve in the valley of the midstream of the Yarlung Zangbo River was analyzed and evaluated. Results show that the sum in area of the habitats suitable and near-suitable to black-necked cranes accounted for 31.05%, 32.00% and 41.00% of the total of the reserve, respectively, in 1994, 2005 and 2015, indicating that their living space was increasing steadily. The comparison between 1994 and 2015 in conversation ratio and conservation efficiency shows that the distribution of habitats suitable for foraging and night-roosting tended to get flocked towards the core area and so did the habitats near-suitable for foraging. Moreover, the programming of the reserve for conservation of habitats suitable for foraging and night-roosting decreased in rationality, while that for conservation of habitats near-suitable to foraging increased. In view of the ratios of various habitats under protection in the epitaxial areas, there seem to be vast tracts of habitats available to black-necked cranes, which, however, have not yet been included in the scope for protection.