RESOURCE AVAILABILITY HYPOTHESIS OF PLANT ANTIHERBIVORE DEFENSE TESTED IN A SOUTH-AFRICAN SAVANNA ECOSYSTEM
RESOURCE AVAILABILITY HYPOTHESIS OF PLANT ANTIHERBIVORE DEFENSE TESTED IN A SOUTH-AFRICAN SAVANNA ECOSYSTEM
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DOI：
10.1038/340227a0
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发表时间：
1989-07-20
期刊：
影响因子：
64.8
通讯作者：
OWENSMITH, N
中科院分区：
文献类型：
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作者：
BRYANT, JP;KUROPAT, PJ;OWENSMITH, N
在北极灌木苔原、北方森林、热带雨林和非洲稀树草原等不同生态系统中，木本物种的食草水平有相当大的差异。进化生态学的一个重要目标是提出一个假说来解释这种变异。一个这样的假设预测，成熟的叶子的固有缓慢增长的物种适应资源有限的habitats 2，3如贫瘠的土壤4，由于更有效的化学防御，不太喜欢作为食物来源的食草动物比成熟的叶子的固有快速增长的物种适应生产性habitats 2，3，5-8。与此预测一致，我们发现南非9种木本植物的固有增长率与捻角羚和黑斑羚对成熟叶片的偏好之间存在正相关关系。因此，植物抗食草动物防御的资源可用性假说2，3，5- 8可以解释为什么大型非洲食草动物在营养不良的稀树草原林地的木本植被上比在富营养化稀树草原的木本植被上吃得少9。
THERE is considerable variation in the levels of herbivory experienced by woody species in ecosystems as diverse as arctic shrub tundra, boreal forests, tropical rain forests and African savannas1. An important objective of evolutionary ecology is the formulation of a hypothesis that can explain this variation. One such hypothesis predicts that mature leaves of inherently slowly growing species adapted to resource-limited habitats2,3such as infertile soil4are, because of more effective chemical defences, less preferred as a food source by herbivores than mature leaves of inherently rapidly growing species adapted to productive habitats2,3,5-8. In agreement with this prediction, we found positive correlations between the inherent growth rates of nine South African woody species and kudu and impala preferences for their mature leaves. Thus, the resource availability hypothesis of plant antiherbivore defence2,3,5-8could explain why large African herbivores feed less on woody vegetation of dystrophic savanna-woodlands than on woody vegetation of eutrophic savannas9.