不同放牧模式对贵南县高寒草甸优势种羊茅叶属性的影响

Effects of Different Grazing Pattern on Leaf Characteristics of Festuca ovina in Alpine Meadow of Guinan County

以青海省贵南县高寒草甸的不同放牧管理模式(适度放牧、重度放牧、季节性休牧及封育)草地为对象,通过对不同放牧模式下高寒草甸优势种羊茅8个叶属性的定量分析,研究不同放牧模式对高寒草甸优质牧草羊茅的影响。结果表明:与适度放牧样地相比,羊茅比叶面积在重度放牧后显著升高(P<0.05),封育后显著下降(P<0.05),叶干物质含量均呈现下降趋势(P<0.05)。放牧使羊茅叶N、P含量表现出增加趋势,N/P表现出降低趋势,在重度放牧样地中表现最为明显(P<0.05)。各样地均有较高N/P,说明P元素是限制羊茅生长的主要营养元素。主成分分析表明,季节性休牧模式下羊茅生长状况较好,重度放牧模式下羊茅生长状况最差。因此,从羊茅叶属性看,应提高休牧模式在草地利用中的比重,降低草地放牧强度,以保证草地质量。

In order to study the effects of different grazing patterns in alpine meadow,eight leaf traits of Festuca ovina,a dominant species in alpine meadow,were quantitatively analyzed under different grazing patterns(moderate grazing,heavy grazing,seasonal rest grazing and enclosure)in Guinan County,Qinghai Province.The results showed that compared with moderate grazing,specific leaf area(SLA)of F.ovina was increased significantly after heavy grazing(P<0.05),decreased significantly after enclosure(P<0.05),and the dry matter content of leaves showed a decreased trend(P<0.05).The content of N and P in leaves of F.ovina increasing trend and N/P showed a decreasing trend after grazing,which was most obvious in the heavy grazing plot(P<0.05).The N/P ration was higher in all plots,which indicated that P was the main nutrient element limiting the growth of F.ovina.Principal component analysis showed that the growth of F.ovina was better under the seasonal rest grazing mode,and the worst under the heavy grazing mode.Therefore,from the leaf characteristics of F.ovina,the proportion of seasonal rest grazing mode in grassland utilization should be increased,and grazing intensity should be reduced to ensure grassland quality.