不同草地利用方式对内蒙古典型草原群落特征及草地健康的影响

Effects of land use patterns on community characteristics and grassland health in Inner Mongolia

为科学评价不同利用方式对典型草原健康的影响,本研究以西乌珠穆沁旗典型草原为研究区,通过群落调查结合Condition-Vigor-Organization-Resilience(CVOR)草地健康评价模型,综合评价放牧刈割草地(MG)、夏季放牧草地(SG)、冬季放牧草地(WG)、禁牧刈割草地(MP)4种不同利用方式对草地健康的影响。研究发现:1)冬季放牧草地群落平均高度显著低于其他利用方式(P<0.05),夏季放牧草地平均盖度、密度显著低于其他利用方式(P<0.05),放牧是影响群落形态特征的主要因素之一,夏季放牧草地Shannon-Wiener指数和Simpson指数显著低于其他利用方式(P<0.05)。放牧刈割提高了群落的的丰富度和均匀度。2)冬季放牧草地群落生物量和凋落物量显著低于其他利用方式。3)基于CVOR指数评价综合草地健康等级:MG>MP>WG>SG,放牧刈割草地综合草地健康指数最高(HCVOR=0.84),其余3种利用方式处于“不健康”状态。应适当加强对放牧刈割草地的利用,对其他3种利用方式进行因地制宜的草地管理措施,以期全面恢复内蒙古典型草原健康水平。

To evaluate the effects of different land use patterns on the health of typical grasslands,this study investigated the grassland in Xiwuzhumuqin banner.Through community investigation and using the condition vigor organization resilience(CVOR)grassland health evaluation model,comprehensive evaluation of grazing and mowing grassland(MG),summer grazing grassland(SG),and winter grazing grassland(WG)was carried out.The effects of four different utilization patterns of grazing prohibition and mowing grassland(MP)on grassland health were investigated.The results showed that:1)The average height of the grazing grassland community in winter was significantly lower than those observed with other utilization practices(P<0.05);the average coverage and density of the summer grazing grassland were significantly lower(P<0.05);grazing was one of the main factors affecting the morphological characteristics of the community;and the Shannon Wiener index and Simpson index of the summer grazing grassland were significantly lower than those observed with other utilization practices(P<0.05).Grazing and mowing increased the richness and consistency of the community.2)The community biomass and litter amount of the grazing grassland in winter were significantly lower than those observed with other utilization methods.3)The comprehensive grassland health grade based on the CVOR index for each method was MG>MP>WG>SG;the comprehensive grassland health index of the grazing and mowing grassland was the highest((HCVOR=0.84),and the other three utilization modes were determined to exhibit an unhealthy state.In order to restore the health level of the typical grasslands in Inner Mongolia,the utilization of grazing and mowing grassland should be strengthened,and grassland management measures should be adopted according to the local conditions.