Maintenance of high diversity in mechanistic forest dynamics models of competition for light
Maintenance of high diversity in mechanistic forest dynamics models of competition for light
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DOI：
10.1002/ecm.1500
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发表时间：
2022-02-01
影响因子：
6.1
通讯作者：
Pacala, Stephen W.
中科院分区：
文献类型：
--
作者：
Detto, Matteo;Levine, Jonathan M.;Pacala, Stephen W.
虽然早期的理论工作表明，竞争光侵蚀演替多样性的森林，口头模型和最近的数值工作与复杂的机械森林模拟器表明，在这样的系统中的干扰可以保持演替多样性。尽管如此，如果以及如何分配竞争对手之间的权衡相互作用的干扰，以保持高度的多样性演替系统仍然知之甚少。在这里，使用机械和易于分析的模型，我们表明，理论上无限数量的共存物种可以保持分配权衡，如投资于捕光器官与高度增长，投资于繁殖与增长或生存与增长。该模型描述了森林的演替动力学组成的许多补丁受到随机或周期性的干扰，是一致的生理机制的陆地生态系统模型，包括最近的地球系统模型的陆地组件。我们表明，共存出现在我们的模型，因为物种专门在演替的时间，他们最好地利用光环境和资源转化为种子或促进再生。我们还表明，我们的研究结果是相关的非森林生态系统中出现的一年生植物物种之间的光竞争的机械模型，展示了类似的动态。最后，我们表明，在我们的模型中的共存是相对稳健的引入种内变异，削弱了竞争的层次结构所造成的不对称竞争的光。
Although early theoretical work suggests that competition for light erodes successional diversity in forests, verbal models and recent numerical work with complex mechanistic forest simulators suggest that disturbance in such systems can maintain successional diversity. Nonetheless, if and how allocation trade-offs between competitors interact with disturbance to maintain high diversity in successional systems remains poorly understood. Here, using mechanistic and analytically tractable models, we show that a theoretically unlimited number of coexisting species can be maintained by allocational trade-offs such as investing in light-harvesting organs versus height growth, investing in reproduction versus growth or survival versus growth. The models describe the successional dynamics of a forest composed of many patches subjected to random or periodic disturbance, and are consistent with physiologically mechanistic terrestrial ecosystem models, including the terrestrial components of recent Earth System Models. We show that coexistence arises in our models because species specialize in the successional time they best exploit the light environment and convert resources into seeds or contribute to advance regeneration. We also show that our results are relevant to non-forested ecosystems by demonstrating the emergence of similar dynamics in a mechanistic model of competition for light among annual plant species. Finally, we show that coexistence in our models is relatively robust to the introduction of intraspecific variability that weakens the competitive hierarchy caused by asymmetric competition for light.