内蒙古自治区锡林郭勒盟2012-2021年气象因素和鼠体蚤指数对长爪沙鼠种群密度的影响

The impact of meteorological factors and flea index on the density of Meriones unguiculatus in Xilingol League,Inner Mongolia Autonomous Region,China,2012-2021

目的探究气象、归一化植被指数(NDVI)及鼠体蚤指数等因素及其交互作用对锡林郭勒盟长爪沙鼠密度的影响。方法收集2012-2021年锡林郭勒盟长爪沙鼠密度及其体蚤指数资料,同时收集气象和NDVI资料,通过R 4.2.2软件进行广义可加建模,对鼠密度的影响因素进行分析。结果长爪沙鼠密度表现出明显的时间趋势(F=3.129,P=0.004),体蚤指数和月平均相对湿度与长爪沙鼠密度存在显著的非线性负效应(F=1.833,P=0.044;F=2.949,P=0.011)。滞后3个月的月平均最低气温与长爪沙鼠密度存在显著的非线性正效应(F=2.418,P=0.032),鼠密度随着月平均最低气温的升高呈现先增高后下降再增高的趋势。滞后1个月的月平均日照时数与长爪沙鼠密度呈线性正相关(F=7.876,P=0.005)。滞后2个月的月平均气压与长爪沙鼠密度呈现倒“U”形(F=4.752,P=0.002),当气压<880 hPa时两者呈正相关,反之呈负相关。体蚤指数与滞后3个月的月平均最低气温和月平均相对湿度对长爪沙鼠密度的影响均存在交互作用(F=2.689,P=0.009;F=2.644,P=0.017)。结论体蚤指数、月平均最低气温、月平均相对湿度、月平均日照时数以及月平均气压对长爪沙鼠密度均有调节作用,且各影响因素对长爪沙鼠密度的影响部分存在滞后效应和交互作用。

Objective To investigate the individual and interactive impact of various factors(including meteorological conditions,the normalized difference vegetation index[NDVI],and flea index)on the population density of Meriones unguiculatus in Xilingol League,Inner Mongolia Autonomous Region,China.Methods The data of M.unguiculatus density and body flea index as well as meteorological and NDVI data in Xilingol League from 2012 to 2021 were collected.Generalized additive models were employed to analyze the factors influencing the gerbil density with R 4.2.2 software.Results The density of M.unguiculatus exhibited a significant temporal trend(F=3.129,P=0.004).Significant nonlinear negative effects on M.unguiculatus density were observed for the flea index(F=1.833,P=0.044)and monthly average relative humidity(F=2.949,P=0.011).Lag-3-month monthly average minimum temperature had a significant nonlinear positive effect on the gerbil density(F=2.418,P=0.032):with rising monthly average minimum temperature,the gerbil density initially increased,then declined,and increased again.A linear positive correlation existed between lag-1-month monthly average sunshine duration and the gerbil density(F=7.876,P=0.005).Lag-2-month monthly average air pressure and the gerbil density showed an inverted U-shaped relationship(F=4.752,P=0.002),which was positive when monthly average air pressure was<880 hPa and negative otherwise.Interactive effects were found between the flea index and lag-3-month monthly average minimum temperature(F=2.689,P=0.009)and between the flea index and monthly average relative humidity(F=2.644,P=0.017)on the gerbil density.Conclusion The flea index,monthly average minimum temperature,monthly average relative humidity,monthly average sunshine duration,and monthly average air pressure can influence the density of M.unguiculatus,and lag effects and interactive effects exist among these influencing factors.