Abstract: To explore the relationship between diet diversity and the population of small mammalian herbivores,this study measured the effects of diet diversity on survival rate and body growth rate of young Brandt's voles(Lasiopodomys brandtii) fed diets with five different common herbaceous plants containing Leymus chinensis,Stipa krylovii,Medicago sativa,Allium mongolicum,or Convcolvulaceae sepium.The results showed that(1) As the richness of food items increased,the survival rate of young Brandt's vole was significantly increased(P<0.05).Compared with voles fed with diet only containing one plant species,voles fed with diet containing 2,3 and 4 plant species increased their survival rates by 15.6%,18.0% and 12.2% respectively.Each specific plant species contributed differently to the survival rate of young Brandt's vole(P<0.01).With the increase in the proportion of Stipa krylovii and Convcolvulaceae sepium in the dietary,the survival rate of young Brandt's vole was significantly decreased(P<0.05).(2) As the richness of food items increased,the body growth rate of young Brandt's vole was significantly decreased at fifth weeks(P<0.05).Each specific plant species contributed differently to the body growth rate of young Brandt's vole(P<0.01).With the increase in the proportion of Leymus chinensis in the dietary,the body growth rate of young Brandt's vole was significantly increased at fifth week(P<0.01).With the increase of the proportion of Stipa krylovii in the dietary,the body growth rate of young Brandt's vole was significantly decreased at third and fifth week(P<0.05).With the increase in the proportion of Convcolvulaceae sepium in the dietary,the body growth rate of young Brandt's vole was significantly decreased at third week(P<0.01).Diet diversity improves the survival rate and reduces the body growth rate of the young Brandt's vole,the survival rate and the body growth rate of young Brandt's vole were reduced by Stipa krylovii and Convcolvulaceae sepium,the body growth rate of Brandt's vole was improved by Leymus chinensis.Diet diversity can influence survival rate,growth and population density of Brandt's voles.

Key words: Brandt's vole(Lasiopodomys brandtii), Diet diversity, Survival rate, Body growth rate

摘要： 为探明食物多样性对植食性小型哺乳动物种群的影响，以羊草、克氏针茅、紫花苜蓿、沙葱和阿氏旋花5种实验地常见的草本植物，组成不同食物多样性的食谱，饲喂布氏田鼠幼体，探究布氏田鼠幼体的存活率和生长率对不同食物多样性的响应。结果表明：（1）随着食物多样性种类的增加，布氏田鼠幼体存活率显著提高（P<0.05）。与单一食物组相比，2~4种食物组饲喂的布氏田鼠幼体存活率分别增加15.6%、18.0%和12.2%；不同食物占食谱的比例对布氏田鼠幼体存活率变化具极显著作用（P<0.01）；随着克氏针茅、阿氏旋花在食谱中比例的增加，布氏田鼠幼体存活率显著下降（P<0.05）。（2）随着食物多样性的增加，布氏田鼠幼体生长率在第5周时极显著降低（P<0.01）；不同食物在食谱中的比例对布氏田鼠幼体生长率变化具有显著影响（P<0.01）。随着羊草在食谱中比例的增加，在第5周时布氏田鼠幼体生长率极显著提高（P<0.01），随着克氏针茅在食谱中比例的增加，至第3周和5周时布氏田鼠幼体的生长率均显著下降（P<0.05），随着阿氏旋花在食谱中比例的增加，至第3周时布氏田鼠幼体生长率极显著下降（P<0.01）。结果表明，布氏田鼠幼体随着克氏针茅和阿氏旋花在其食物中所占比例增加，布氏田鼠幼体存活率和生长率相应下降，随着羊草在布氏田鼠幼体食谱中比例增加其生长率显著提高。因此，食物多样性在一定程度影响布氏田鼠幼体存活、生长和种群密度。

关键词: 布氏田鼠, 食物多样性, 存活率, 生长率