Herbivore‐Mediated Ecological Costs of Reproduction Shape the Life History of an Iteroparous Plant
Herbivore‐Mediated Ecological Costs of Reproduction Shape the Life History of an Iteroparous Plant
复制标题
DOI：
10.1086/524961
复制
发表时间：
2007-12
期刊：
影响因子：
--
通讯作者：
T. Miller;B. Tenhumberg;S. Louda
中科院分区：
文献类型：
--
作者：
T. Miller;B. Tenhumberg;S. Louda
植物繁殖产生直接的健身效益，但在生存，生长和未来的繁殖力方面可能是昂贵的。生活史理论认为，生殖策略是由这些直接生殖成本导致的当前和未来适应性之间的权衡决定的。如果植物繁殖增加了对食草动物的敏感性，也可能产生间接的生态成本。然而，繁殖的生态成本很少受到经验主义的关注，并且仍然没有很好地融入生活史理论。在这里，我们提供了食草动物介导的繁殖生态成本的证据，我们发展理论来研究这些成本如何影响植物生活史策略。一个iteroparous仙人掌（仙人掌imbricata）的田间实验表明，更大的生殖努力（分配给生殖的分生组织的比例）导致更大的攻击仙人掌喂养昆虫（纳尼亚pallidicornis），这种草食动物的损害降低了生殖成功。一个动态规划模型预测强烈分歧的最佳繁殖策略时，生态成本被包括在内，当这些成本被忽略。仙人掌在田间的分生组织分配符合繁殖生态代价下的最优策略。结果表明，植物的生殖分配可以强烈地影响与食草动物的相互作用的强度和相关的生态成本可以发挥重要的选择作用，在植物生活史的演变。
Plant reproduction yields immediate fitness benefits but can be costly in terms of survival, growth, and future fecundity. Life‐history theory posits that reproductive strategies are shaped by trade‐offs between current and future fitness that result from these direct costs of reproduction. Plant reproduction may also incur indirect ecological costs if it increases susceptibility to herbivores. Yet ecological costs of reproduction have received little empirical attention and remain poorly integrated into life‐history theory. Here, we provide evidence for herbivore‐mediated ecological costs of reproduction, and we develop theory to examine how these costs influence plant life‐history strategies. Field experiments with an iteroparous cactus (Opuntia imbricata) indicated that greater reproductive effort (proportion of meristems allocated to reproduction) led to greater attack by a cactus‐feeding insect (Narnia pallidicornis) and that damage by this herbivore reduced reproductive success. A dynamic programming model predicted strongly divergent optimal reproductive strategies when ecological costs were included, compared with when these costs were ignored. Meristem allocation by cacti in the field matched the optimal strategy expected under ecological costs of reproduction. The results indicate that plant reproductive allocation can strongly influence the intensity of interactions with herbivores and that associated ecological costs can play an important selective role in the evolution of plant life histories.