本研究通过在玛曲县退化高寒草甸草原实施不同草地改良措施后,对高原鼠兔发生生境的适合度进行调查分析,以期揭示当地高原鼠兔发生机理,并为有效开展高原鼠兔的生态防治提供理论依据和技术支撑.于2010年5月至2010年7月,对玛曲县退化高寒草甸草原进行围封、补播、施肥、划破等12种不同草地改良措施,通过堵洞盗洞法监测高原鼠兔种群密度,并结合样方法测定植被等生境因子,探讨玛曲退化高寒草甸草原高原鼠兔发生生境的适合度.研究结果表明:与采用改良措施前相比,不同改良措施下有效鼠洞密度均表现出差异显著性(P〈0.05).所有草地改良措施均显著降低了有效鼠洞密度(P〈0.05),且补播措施显著优于其他措施(P〈0.05).有效鼠洞密度与群落结构的相关性及逐步回归分析表明,有效鼠洞密度与草层高度呈显著的负相关(P〈0.05),因而在高寒草甸,植物群落草层高度是决定鼠群密度的重要因子,而禾草类高度是决定草层高度的重要因素.两年的植被定向调控试验表明,在该区不同草地改良措施均能有效降低有效鼠洞密度,而补播禾草和增施有机肥,增加植物群落中禾草的比例,进而提高整体草层高度,可显著降低有效鼠洞密度(P〈0.05).因此提出“增加植物群落中禾草比例,治理高原鼠兔危害”的生物防治模式.
We analyzed the selection of habitat by plateau pika in degraded alpine meadow in Maqu County through different grassland improvement measures including enclosure,reseeding,fertilization (organic)and cleavage to help reveal aspects of the ecology of plateau pika and to provide theoretical basis for ecologically based management of plateau pika.From May to July 2010,12 different grassland improvement measures were implemented.The density of active pika burrows was estimated using a stolen hole (mousehole)technique,and the selection of habitat by pika assessed.Compared with the control,the density of active pika burrows un-der different treatment measures was significantly reduced (P <0.05).All of the grassland improvement meas-ures,especially reseeding,decreased the density of active burrows.The relationship between active burrow density and community structure was analysed using correlation analysis and stepwise regression analysis;the density of active burrows was significantly,negatively correlated with grass layer height (P <0.05).This sug-gests that grass height is an important factor influencing the density of pika.Using multiple management con-trol factors including reseeding and fertilizer application promoted grass productivity,increasing grass layer height,decreasing active burrow densities (P <0.05).In alpine meadow areas of Maqu,different grassland improvement measures can effectively reduce the density of pika burrows,particularly those which increase the proportion of the grasses in the meadow.