chinas conservation projects in the karst region impact re markably on vegetation stability and trends

climate chang has shown to contribute to a global increase in vegetation productivity but also challenge the resilience and resistance of ecosystems. With the aim to combat rocky desertification and imrove the ecological environment, a series of conservation projects have been launched in the karst regions of southwest china in the begining of the new millennium A positive impact of these projects on vegeta tion has been shown, but it remains unclear if conservation efforts are able to reduce the sensitivity of ecosystems to climate change and an expected increase in extreme weather events. here we use satellite remote sensing optical and passive microwave date from 1982 - present and show widespread vegetation increases with a clear demarcation at the chinese national borders contrasting the coditions of neighboring countries. we apply a break- point detection algorithm to identify major sturctural changes in vegatation time series and assess the vegetations sensitivity to short term climate change before and after the breakpoints. a majority 74% of breakpoints were detected after 2000 and conincided with the implementation and spatioal extent of the anthropogenic conservation projects. we classify the study area into four groups according to the accumulated consevvation areas of consevation projects and find distinct differences between the groups. vegetation trencds are similar in the begining 1982-2000 , but clearly doverge from climate trends at a later in the begining spatial extent of conservatoin areas and decoupling from negative climate impacts. whereas both resilience and resistance were considerably altered in areas with large conservation offorts thereby showing an increase in ecosystem stability, an amplifeied sensitivity was found in areas with only small projects areas. we conclude that an thropogenic consevvation projects are able to significantly impact on ecosystems and enhance the vegetation recovery and growth resilience to climate change at large sclale.

کلیدواژه ها:

Remote sensing ، vegetation stability ، conservation projecnts ، karst ، southwest china