Land-cover changes of national nature reserves in China.

For preventing ecosystem degradation, protecting natural habitats and conserving biodiversity within the habitats, 2588 nature reserves have been established in China at the end of 2010. The total area is up to 149.44 million ha and covers over 15% of Chinese terrestrial surface. Land-cover change, as the primary driver of biodiversity change, directly impacts ecosystem structures and functions. In this paper, 180 National Nature Reserves (NNRs) are selected and their total area is 44.71 million ha, accounting for 29.9% of all NNRs in China. In terms of the ecosystem characteristics and their major protected object, all selected NNRs are classified into 7 types. A Positive and Negative Change Index of Land-cover (PNCIL) was developed to analyze the land-cover change of each NNRs type from the late 1980s to 2005. The results show that the land-cover of all selected NNRs types have degradated to a certain degree except the forest ecosystem reserves with a decreasing rate, but the rate of degradation alleviated gradually. The mean positive and negative change rates of land-cover in all core zones decreased by 0.69% and 0.16% respectively. The landscape pattern of land-cover in the core zones was more stable than that in the buffer zones and the experimental zones. Furthermore, the ecological diversity and patch connectivity of land-cover in selected NNRs increased generally. In short, the land-cover of 180 selected NNRs in China had a beneficial change trend after NNRs established, especially between 1995 and 2005. [ABSTRACT FROM AUTHOR]