吉林省乾安县鼠疫自然疫源地环境改变对宿主种群变化的影响

Effect of environment change on population of host animals in plague foci in Qian’an County of Jilin Province

目的利用乾安县自开展鼠疫监测以来宿主种群变化趋势,探讨环境改变对宿主种群变化的影响,为鼠疫监测调整提供理论依据。方法选取乾安县鼠疫自然疫源地内各监测点宿主监测数据,主要宿主监测采用样方法、小型鼠监测采用5 m夹笼法。种群数量变化按照鼠密度、主要宿主及小型鼠数量构成进行描述分析,种群结构变化按照物种多样性指数(H)、均匀性指数(J)、生态优势度(C)描述分析。结果鼠密度在五十年代末期较高,六十年代初降到0.1~0.5只/公顷后,八十年代中期再次升高后呈现波状变化至2000年,2000年后在0.4只/公顷左右;八十年代初期,主要宿主构成占70%左右,中后期逐渐降低至2000年的20%左右后逐渐升高,近年升高到60%~70%左右;小型鼠种群变化中物种多样性指数和均匀性指数在八十年代初期由0.8左右降至0.2左右后逐渐升高,2000年后在0.6~1.2间呈现波状变化。结论环境变化或人为作用可以改变宿主数量和种群构成,宿主数量和种群结构的改变会影响鼠疫菌的保存和传播,从而影响鼠疫的发生和流行。

Objective To find out the relation between the environment and the host population,and provide theoretical basis for plague monitoring strategy adjustment.Methods Data of plague host animals in plague foci in Qian’an county was chosen.Primary host monitoring used sample method;Small rat monitoring used 5m Clip cage method.Population change methods including Shannon-Wiener index(H),Pielou(J),Simpsin(C)description.Results The rodents’density was high in Late 1950s,it reduced to 0.1 to 0.5/ha,after the rise in the mid of 1980s,it showed a wave change until to 2000.after 2000,it was only 0.4/ha;In the early 1980s,the main host composition accounted for about 70%,In the middle and late stage,it gradually decreased to about 20%in 2000 and then gradually increased,In recent years,it has increased to about 60%to 70%.The species diversity index and uniformity index of the small mouse population decreased from 0.8 to 0.2 in the early 1980s,and then gradually increased.After 2000,the undulate changes occurred between 0.6 and 1.2.Conclusion Environmental changes or man-made effect can change the host population and host number,change of the host number and population will affect the preservation and transmission of Yersinia pestis,which affect the occurrence and epidemic of the plague.