高寒草甸和高寒草原高原鼠兔的生态阈值确定及为害预测模型构建

Determination of ecological thresholds and construction of hazard prediction models for plateau pika Ochotona curzoniae in alpine meadows and alpine steppes

为完善高原鼠兔Ochotona curzoniae的防治指标,采用无人机遥感与地面调查相结合的方法对73块高寒草甸样地和26块高寒草原样地进行调查,获得秃斑率、地上生物量、有效洞口数、群落高度、物种丰富度、可食牧草比例、Shannon-Wiener多样性指数及Pielou均匀度指数8个监测指标数据,通过分析高原鼠兔的有效洞口数与除可食牧草比例外其他指标的关系确定2种草地类型高原鼠兔的生态阈值,利用8个监测指标数据计算鼠害指数,根据鼠害指数划分高原鼠兔的为害等级,并采用逐步回归法构建2种草地类型下高原鼠兔的为害预测模型。结果显示:高寒草甸高原鼠兔生态阈值为有效洞口数613个/hm^(2),秃斑率13%,地上生物量160 g/m^(2);高寒草甸高原鼠兔为害预测的关键因子是有效洞口数、秃斑率和地上生物量。高寒草原高原鼠兔生态阈值为有效洞口数205个/hm^(2),群落高度3 cm,物种丰富度8种;高寒草原高原鼠兔为害预测的关键因子是有效洞口数、群落高度和物种丰富度。

In order to improve the control index of plateau pika Ochotona curzoniae,a combination of unmanned aerial vehicle remote sensing and ground investigation was used to investigate 73 alpine meadow plots and 26 alpine steppe plots.Data were collected on eight monitoring indicators,including the ratio of bare patch,aboveground biomass,number of effective burrows,community height,species richness,proportion of edible forage,Shannon-Wiener diversity index and Pielou evenness index.The ecological thresholds of plateau pikas in two grassland types were determined by analyzing the relation-ship between the number of effective burrows of plateau pikas and other indicators,excluding the pro-portion of edible forage.The rodent damage index was calculated using the data of eight indicators,and the damage grades were categorized according to the rodent damage index.The damage prediction mod-els for plateau pikas in both grassland types were constructed by stepwise regression.The results showed that in the alpine meadow area,the ecological thresholds for plateau pikas were 613 effective burrows per hectare,a bare patch rate of 13%,and an aboveground biomass of 160 g/m^(2).The key fac-tors for predicting the damage of plateau pikas in the alpine meadow area were the number of effective burrows,the bare patch rate and the aboveground biomass;in the alpine steppe area,the ecological thresholds of plateau pikas were 205 effective burrows per hectare,a community height of 3 cm,and a species richness of eight species.The key factors for predicting the damage of plateau pikas in the al-pine steppe were the number of effective burrows,the community height and species richness.