田鼠种群波动的原因和时间(英文)  

Vole Population Fluctuations: Why and When?

作　　者：Lowell L. Getz 

机构地区：[1]Department of Animal Biology, University of Illinois, 505 S. Goodwin Ave., Urbana, IL 61801, USA

出　　处：《兽类学报》2005年第3期209-218,共10页Acta Theriologica Sinica

基　　金：ThestudywassupportedinpartbygrantsNSFDEB78-25864andNIHHD09328andbytheUniversityofIllinoisSchoolofLifeSciencesandGraduateCollegeResearchBoard

摘　　要：本文总结了橙腹田鼠(Microtus ochrogaster)和草原田鼠(M. pennsylvanicus)25年的种群统计学研究结果和结论。探讨了田鼠种群波动周期性、诱发种群波动以及导致波动期间峰值变异的因素。并对种群存活值和繁殖活动的作用进行了分析和评价。根据两种田鼠种群波动周期性、波动峰值出现的时间以及特定年份峰值的高度等特征,证明两物种波动均具有不稳定性。两种田鼠存活值的变化是由特定年份是否发生波动以及波动峰值出现的时间决定。增加初始阶段的种群密度及时间长度是造成两种动物种群波动峰值不同的主要原因。橙腹田鼠种群停止增长的原因是存活值降低,而草原田鼠则是繁殖活动减少。据推测,与种群波动初始密度相关的种群死亡率的差异是由捕食者的净效应(Net effect)决定的,调控两种群密度的因素均为非密度的其它生态学因子。由于特定年份田鼠种群捕食压力的不确定性,导致了橙腹田鼠和草原田鼠种群波动的不稳定性。In this paper Ⅰ stunmarize the results and conclusions of a 25-year study of demography of the prairie vole （ Microtus ochrogaster ）, and meadow vole （ M. pennsylvanicus ）. The roles of survival and reproduction are evaluated in respect to why population fluctuations occur some years and not others, what initiates a population fluctuation, and what is responsible for the variation in the peak density among population fluctuations. Population fluctuations of both species were erratic in respect to annual occurrence, the time of the peak density of fluctuations within years, and the hight of peak the density a given year. For both species, changes in survival appeared to be. responsible for whether a fluctuation occurred a given year and the time of the peak density of a fluctuation. Population density at the beginning of the increase phase and length of the increase were most responsible for variation in peak densities of population fluctuations of both species. Stoppage of growth of populations of M. ochrogaster resuited from decreased survival, whereas stoppage of most population fluctuations of M. pennsy/varticus resulted from decreased reproduction. Variation in mortality associated with initiation of a population fluctuation is presumed to result primarily from the net effect of a consortium of generalist predators, populations of each which are controlled by factors other than vole densities. Accordingly, predation pressure on vole populations a given year is presumed to be unpredictable, resulting in the observed erratic nature of population fluctuations of M. ochrogaster and M. pennsylvarticus.

关 键 词：橙腹田鼠 草原田鼠 种群周期 种群波动 田鼠 

分 类 号：Q958[生物学—动物学]