The analysis of grassland carrying capacity and its impact factors in typical mountain areas in Central Asia—A case of Kyrgyzstan and Tajikistan

Grasslands are among the main important terrestrial ecosystems on the earth. Central Asia has the biggest grazing part in the world due to a favorable environmental condition for the development of livestock farming. Thus, the evaluation of the health and productivity of such an ecosystem is so pertinent. This study aims at analyzing the grassland capacity dynamics in Tajikistan (TJK) and Kyrgyzstan (KGZ) mountains using Geographic Information System (GIS) and Remote Sensing (RS) techniques. Initially, the mountain boundaries were derived using the United Nations Environment Programme World Conservation Monitoring Centre (UNEP/WCMC) classification. Different datasets were used to calculate the seasonal dynamics of grassland carrying capacity in different periods (2000, 2010 and 2015) and we analyzed their driving factors. The main results showed that: (1) The mountainous area accounts for 89% and 91% in KGZ and TJK, respectively. (2) In both countries, the highest grassland carrying capacity was identified during the summer because of the high foraging value in relatively warm and humid conditions. From 2000 to 2015, the changing trend of mountain grassland carrying capacity in the two countries were similar in summer and autumn, both showed an increasing trend in summer, with 53.9% SU/hm2 in TJK and 5.2% SU/hm2 in KGZ; The grassland carrying capacity in autumn increased from 2000 to 2010 and then decreased from 2010 to 2015. In spring, changing trends showed that KGZ gradually decreased, while TJK showed a slightly increasing trend from 2000 to 2015. (3) From annual characteristics, the grassland capacity from 2000 to 2015 has increased by 43.9 SU/hm2 and 82.5 SU/hm2 in KGZ and TJK, respectively. The regions where the grassland carrying capacity increased in both countries were mainly located in the western and middle part of KGZ mountains while in TJK, the regions were identified in the southwest. (4)In 2010, the overgrazing ratio was 88.4% SU/hm2 in KGZ and 127.8% SU/hm2 in TJK. In both countries overgrazing region are mainly located in low elevation near the residential areas. (5) It was exhibited that the human-induced overgrazing superimposed the climate change influencing grassland carrying capacity in this study. Moreover, the results of this study are useful for leading regional livestock control mechanisms and environmental protection.