自由牧马对草甸草地群落结构及牧草品质的影响:以新疆昭苏夏马场为例研究

Effects of Horse Grazing on Community Structure and Forage Quality of Meadow Grassland:a Case Study of Summer Horse Grassland in ZhaoSu,Xinjiang

为探明自由牧马对草甸草地群落结构及牧草品质的影响,在新疆昭苏夏马场设置放牧试验,采用控制笼进行对照,分析了2013-2015年草地群落结构及牧草营养品质的动态变化。结果表明:(1)无芒雀麦(Bromus inermis)、羊茅(Festuca ovina)等一些马喜食的禾本科牧草的相对密度降低,狼毒(Euphorbia fischeriana)、龙胆(Gentiana scabra)等一些毒性植物和马不食植物的相对密度升高,但主要优势植物变化不大;(2)在3年夏场放牧中,草甸草地多样性指数(Simpson指数)维持在0.74～0.81;不同植物种类重要值变化趋势不同,白三叶(Trifolium repens)、草地早熟禾(Poa pratensis)和龙胆在群落中重要值增加,而细果苔草(Carex stenocarpa)和羊茅的重要值显著降低;(3)牧草中的中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)总体呈现上升趋势;粗蛋白(CP)含量随着放牧年限的增加从13.4%下降到11.3%,仍可达到马对粗蛋白含量(8%)的基本要求。由试验可知:目前的放牧强度(5匹马·ha-1)基本维持了草地的可持续性,但一定程度上降低了牧草的品质。

In order to explore the influence of horse grazing on the community structure and forage quality of meadow grassland,a grazing experiment was conducted in a summer horse grassland of ZhaoSu,Xinjiang. The dynamic changes of meadow community structure and forage quality in 2013-2015 years were analyzed using the technique of control cage. The results showed that:(1) Grazing in summer grassland led to a decrease in the relative density of some preferred grasses by horse such as smooth bromegrass,Festuca,etc.,and an increase in some toxic plants and no-eating plants such as Euphorbia,Gentian,etc.. The main dominant plants did not change much.(2) The Simpson Diversity index of meadow grassland remained at 0.74~0.81,and the important values of different plant species changed in different trends. The important value of white clover,Kentucky bluegrass and Gentian in the community increased,while that of Carex stenocarpa and Festuca decreased significantly.(3) Neutral detergent fiber and acid detergent fiber showed an upward trend;Crude Protein decreased from 13.4% to 11.3% with the increase of grazing period,but was much higher than the 8% CP basic requirements of the horse. The results showed that the current grazing intensity (5 horses ·ha -1 ) basically maintained the sustainability of grassland,but to a certain extent,the quality of forage was reduced.