• •    下一篇

外果皮厚度和种子大小对五种栎属橡子扩散的影响

雷晶洁,申圳,易现峰   

  1. 河南科技大学农学院
  • 出版日期:2012-05-24 发布日期:2012-05-20

Pericarp thickness and seed size determine acorn dispersal of five rodent-dispersed oak species

  • Online:2012-05-24 Published:2012-05-20

摘要: 动物对种子的扩散和贮藏是一个复杂的生态学过程,常常受到种子特征的影响。有关种子特征如何影响动物对种子扩散,许多研究结果并非完全一致。我们于2009 年9 月在黑龙江东方红林场野外和围栏内释放五种栎属橡子(Quercus mongolica,Q.serrata var. brevipetiolata,Q. aliena,Q.variabilisQ. liaotungensis),研究种子特征对鼠类(Apodemus peninsulae, Clethrionomys rufocanus Tamias sibiricus)扩散和埋藏橡子的影响。野外释放结果表明:橡子大小和外果皮厚度显著影响鼠类对橡子的扩散和埋藏。鼠类偏向扩散和埋藏种皮厚的大橡子,种皮薄的小橡子则多被原地取食。种皮厚的大橡子扩散距离显著高于种皮薄的小橡子。然而,只有外果皮的厚度显著影响围栏内花鼠对橡子的扩散和埋藏,橡子大小并非主要的影响因素。种子特征影响种子扩散的效应可能在种群和群落水平上存在差异。

关键词: 鼠类, 外果皮厚度, 橡子, 种子大小, 种子扩散

Abstract: Because the seed-eating and-hoarding behaviors of animals are complicated by seed traits,the relationships between seed traits and seed dispersal in animal-dispersed plants are still contentious and need further study. Here,we examined acorn dispersal,both in the field and in enclosure,of five rodent-dispersed oak species (Quercus mongolica, Q. serrata var. brevipetiolata,Q. aliena,Q. variabilis and Q. liaotungensis)with different morphological and chemical traits, to further explore the complex interactions between seed traits and seed dispersal. The results of the field studies showed that acorns with large size and thick pericarp were more likely to be cached than eaten by small rodents, suggesting the importance of seed mass and seed coat thickness in determining seed dispersal at the community level of rodents. Large size and thick pericarp acorns were dispersed further in the field,supporting previous studies that seed dispersal distances are positively correlated with seed mass and seed coat thickness. However, in the enclosures, only pericarp thickness of acorns consistently influenced seed removal,dispersal,and caching by Tamias sibiricus at the population level. Our studies indicate that the effect of seed traits on seed dispersal can be different at population and community levels,and therefore some caution is required in elucidating rodent-mediated seed dispersal measures.