基于CVOR指数的巴音布鲁克高寒草原健康评价

Assessment on the Health of Alpine Steppe in Bayinbuluk Based on CVOR Index

利用草地生态系统健康评价CVOR综合指数,对巴音布鲁克高寒草原生态系统2004—2012年健康状态进行评价与退化分级研究,并对引起CVOR变化的内在驱动力因素进行探讨。结果表明:(1)研究区高寒草原生态系统健康状况由一般病态(2004年CVOR=0.58)逐渐恢复为健康状态(2012年CVOR=0.72);退化状况由强度退化恢复为中度退化,但局部仍存在强度退化;(2)降水是高寒草原生态系统CVOR指数的主要限制因子,降水也是除基况外各分指数变化的重要驱动因素;在气候变化背景下,CVOR指数将上升;(3)放牧改变了围栏外的群落功能组分,围封可以改善高寒草原生态系统的健康状况,有利于植被的正向演替,过度放牧是影响高寒草原恢复和演替的重要因素。总体上,降水和放牧是影响研究区高寒草原健康状况的主要原因。

In this study,the CVOR index instead of VOR index and the fuzzy mathematics comprehensive evaluation method were used to evaluate the health conditions of the alpine steppe ecosystem,on which the classification of the degenerated alpine steppe in Bayinbuluk during the period from 2004 to 2012 was carried out. The research results are as follows：（1） The health conditions of steppe ecosystem was gradually regenerated（ CVOR = 0. 72 in 2012 and CVOR = 0. 58 in 2004）,the degeneration of the alpine steppe was relieved,but the serious degeneration was still remained in some regions;（2） Precipitation was the main driving factor of CVOR in alpine steppe in the study area,and the CVOR index was increased under the background of climate change;（3） The community function components outside the fence were changed by grazing,enclosure had some positive effects on the health conditions of the alpine steppe ecosystem,which was conducive to the positive succession of vegetation,overgrazing was one of the important factors affecting the conservation and succession of alpine grasslands. Holistically,precipitation and grazing were the main factors affecting the health conditions of alpine steppe in the study area.