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sur le développement des zones arides et semi-arides

Titre : Damage and Economical Thresholds of Rodent Pest Control in Different Grassland Utilization Methods in Desert Areas

Auteur : 杨可

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé
Rodent damage threshold and economic threshold are indicators that must be clear in the practice of grassland rodent prevention and control.Different grassland types or different utilization methods of the same grassland type have completely different values for these two indicators.The damage threshold is the population density of pests when the grassland is obviously lost,and the economic threshold is the population density that must be controlled when the pest population increases and economic losses are caused.The Alxa desert area is ecologically fragile,and rodent damage has occurred year after year.The study of the grassland rodent prevention and control damage threshold and economic threshold in the desert area has important guiding significance for rodent prevention and control.This study selected continuous grazing areas,rotating grazing areas,and prohibiting grazing areas in the desert area of Alxa Left Banner from 2015 to 2019.Using the mark recapture method to investigate the species and density of pests in spring（April and May）,summer（June July and August）,and autumn（September and October）.Using the sample method to investigate the aboveground biomass of plants.The standard rodent units and the rodents’daily food intake were used to estimate the amount of forage loss,and the regression equation was used to obtain the fitting relationship between the rat density and the ratio of forage loss.The results show:1.There are a variety of harmful rodent species under different grazing methods in the Alxa desert area,and different grazing methods have different dominant rodent species.The dominant rodent species in the continuous grazing area is Allactaga sibirica ;the dominant rodent species in the rotational grazing area are Meriones meridianus and Dipus sagitta ;the dominant rodent species in the prohibiting grazing area is Meridian gerbil.2.The fitting curves of the ratio of rodent density and forage loss under the three grazing methods are in line with the logistic S-shaped curve.3.The best grazing method in spring is prohibiting grazing,the damage threshold is15.3 standard rodent units/hm 2,and the economic threshold is 34.9 standard rodent units/hm 2 ;the best grazing method in summer is rotational grazing,and the damage threshold is 14.2 standard rodent units/hm 2,the economic threshold was 42.0 standard rodent units/hm 2 ;the best grazing method in autumn was prohibiting grazing,the damage threshold was 16.5 standard rodent units/hm 2,and the economic threshold was 30.7 standard rodent units/hm 2.4.In the Alxa desert area,spring,is the best season for prevention and control

Mots clés : Desert steppe ;rodent pest control ;damage threshold ;economic threshold ;

Présentation (CNKI)