Ecosystem Assessment Of Altay Mountains Two-riversource Reserve

Altay Mountains Two-riversource Reserve was studied by expert consultation,field investigation and literature review.In this study,combined with the local characteristics,10 ecosystem assessment indicators were taken and the weight of the evaluation indicators was determined by experts evaluation.Based on the data normalization and the weighed sum,the evaluation model was established to get the change trend of ecosystem in the Altay Mountains Two-riversource Reserve in 1995-2015.The reasons causing the degradation of ecosystem in nature reserve were analyzed based on the evaluation result.The grazing and mining effect on the ecological service value of grassland was studied further.Through the analysis,it mainly comes to the following conclusions:The ecosystem composite indexes of the Altay Mountains Two-riversource Reserve in 1995,2000,2005,2010 and 2015 were 0.686,0.619,0.704,0.537,and 0.569,respectively,which showed a downward trend(P<0.01).It indicates that the whole ecosystem in nature reserve degraded for two decades,and the main causes for the ecological function decline were overgrazing and unreasonable mining behavior;Analysis for the effect of grazing intensity showed that the ecological service value of grassland is 1.59 times of that without grazing under moderate grazing conditions(no more than the theoretical capacity),which indicates moderate grazing is more conducive to reflect the ecological service value of grassland.Under overgrazing conditions,with the grazing intensity from 100%,120%,140%,160% to 180%,the ecological service value of grassland is 1.000,0.911,0.847,0.800 and 0.732,respectively.which indicates overgrazing decreased the ecological service value of grassland;The effects of mining on grassland were analyzed.Before exploitation,the ecological service value of grassland was 3.89 million RMB per year.But the ecological service value of grassland was approximately 0 after exploitation.The cost of 149 million RMB to repair the mining area is 1.8 times of mining income,which shows that the implementation of mining behavior must be careful on the grass.The ecosystem in the Altay Mountains was evaluated quantitatively.Meanwhile,the changes of ecological service value on grassland were calculated from overgrazing and mining aspects.The results are valuable to enrich the theoretical study of grassland ecosystem.