亚热带和热带森林内小型啮齿动物觅食行为差异

摘要

In this study, we surveyed rodent seed predation and dispersal of five common tree species ( Castanop-sis wattii, Lithocarpus hancei, Lithocarpus xylocarpus, Lithocarpus pachyphyllus, Machilns yunnanensis) in a nat-ural subtropical forest located in Ailao Mountain subtropical evergreen broad-leaved forest and Xishuangbanna Na-tional Nature Reserve tropical rainforest. Our results showed that the speed at which rodents harvested seeds in Xishuangbanna were faster than that of Ailao Mountain ( Wald statistic=1 456. 397 , df=1 , P<0. 001 ) . The pro-portion of seeds that were eaten in situ and cached after removal in Xishuangbanna was higher than those in the Ailao Mountains. The rate of harvested seeds and seed size exhibited a negative correlation in Ailao Mountain ( R=-0. 669 , P=0. 050 ) , while a positive correlation was found in Xishuangbanna ( R=0. 048 , P=0. 006 ) . In both sites, there was a negative correlation between the proportion of seeds that were eaten in situ and seed size, but there was no significant correlation between the proportion of seeds that were cached in situ and seed size. In both locations, there was a positive correlation between the proportion of removed seeds and seed size, while the proportion of seeds that were eaten and cached after removal exhibited a negative correlation with seed size. No sig-nificant differences were found in seed dispersal distance in both locations. By pooling all of the removed seed ob-servations within each site, positive relationships between seed size and dispersal distance were found in both the Ailao Mountains ( R=0. 131 , P<0. 001 ) and in Xishuangbanna ( R=0. 313 , P<0. 001 ) . Our results showed that rodents forage similarly at both sites, but rodents in Xishuangbanna may have significant selection processes based on seed size.%利用哀牢山5种主要依靠啮齿动物扩散的变色锥、硬壳柯、木果柯、顺宁厚叶柯和滇润楠种子作为研究材料,研究哀牢山亚热带中山湿性常绿阔叶林和西双版纳热带雨林林内小型啮齿动物觅食行为的差异。结果显示,西双版纳啮齿动物收获5种试验种子的速度比哀牢山更快(Wald statistic=1456.397, df=1, P<0.001)；西双版纳啮齿动物原地取食和搬运后贮藏种子比例均高于哀牢山；种子被收获率与种子大小在哀牢山呈负相关(R=-0.669, P=0.050),而在西双版纳呈正相关(R=0.048, P=0.006)；两地种子原地被取食率与种子大小均呈负相关性,两地原地贮藏率与种子大小均未呈现相关性,两地种子被搬运率与种子大小均呈正相关性,两地种子搬运后被取食率与种子大小均呈负相关性,两地种子搬运后被贮藏率与种子大小均呈负相关性。哀牢山和西双版纳两地种子平均扩散距离没有显著差异,但两地所有被扩散种子个体大小与其扩散距离均呈正相关性(哀牢山, R=0.131, P<0.001；西双版纳, R=0.313, P<0.001)。试验结果表明两地森林内啮齿动物的觅食行为具有相似的选择模型,但西双版纳啮齿动物可能对种子大小具有更明显的选择差异。