植食性哺乳动物觅食功能反应模型机制的检验  

Tests of a model mechanism of functional response in mammalian herbivores foraging

作　　者：陶双伦[1] 刘季科[2] 李俊年[1] 

机构地区：[1]吉首大学资源与环境学院,湖南吉首416000 [2]浙江大学生命科学学院,杭州310012

出　　处：《生态学报》2003年第11期2239-2245,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 ( 3 9970 1 3 3 )~~

摘　　要：植食性哺乳动物在食物密集斑块的觅食为 型功能反应。在新鲜苜蓿叶片构成的食物密集斑块上 ,以高原鼠兔作为实验动物 ,检验植食性哺乳动物的觅食功能反应及其模型机制。食物大小可调节高原鼠兔的口量 ,尽而控制其瞬时摄入率 ;高原鼠兔觅食叶片的口量 S与瞬时摄入率 I存在渐近的函数关系 ,为 型功能反应 ;高原鼠兔的食物收获率 B随口量 S的增加呈非线性递减 ;最大处理速率 Rmax的测定值与模型的预测值极为近似 ;瞬时摄入率 I的测定值与模型的预测值线性回归显著 ( P<0 .0 1 )。研究结果充分验证了提出的假设 :植食性哺乳动物 型功能反应模型能有效地预测其摄入率的动态 ;TypeⅡfunctional responses are frequently observed in mammalian herbivores feeding in patches where plants are concentrated in space We tested a mechanistic model of regulation of intake rate of herbivores foraging in food concentrated patches that accounts for asymptotic, typeⅡresponses. The model is based on the hypothesis that competition between cropping andchewing regulates instantaneous intake rate in response to changes in the size of bites obtained by the forager. We tested this hypothesis and examined the ability of the model to account for observations of intake rate of plateau pikas ( Ochotona curzoniae ). We devised the patches 200×61×50cm 3 thick for pikas, in which fresh alfalfa (Medicago satival) leaves were uniformly spaced 4 5 cm apart to scale leaves distribution, and differences in bite size were imposed by varying the size of leaf offered to animals in patches. Because we were interested in the maximum instantaneous intake rate achievable at a given bite size, trials were kept brief, typically lasting≈2 min. We varied leaf size on the patches. In so doing, we were able to force a 24 fold difference in mass between the largest and smallest bites taken by pikas. We measured dry matter intake rates of 10 individuals, females 5 and males 5, feeding in artificial patches during foraging trails. As the animal was foraging, we counted the number of bites cropped and recorded the elapsed time of active foraging. We used video tapes of trails replayed in slow motion to enhance the accuracy of our counts of cropping bites. We estimated total dry matter intake during a trial as the difference between the dry mass of leaves offered at the beginning of the trial and the dry mass remaining on the patche at the end of the trial. The average bite size consumed during each trial was determined by dividing total amount of leaves removed by the number of cropping bites observed during that trial. All calculations were corrected for dry matter. We designed three model tests. First, we examined

关 键 词：植食性哺乳动物 高原鼠兔 功能反应 叶片大小 口量 瞬时摄入率 收获率 

分 类 号：Q958[生物学—动物学]