Persistence of tri‐trophic interactions in seasonal environments
Persistence of tri‐trophic interactions in seasonal environments
复制标题
季节性环境中三营养相互作用的持续存在
DOI：
10.1111/1365-2656.13368
复制
发表时间：
2020
影响因子：
4.8
通讯作者：
Stouffer, ed., Daniel
中科院分区：
文献类型：
--
作者：
Casas Goncalves, Guilherme;Amarasekare, Priyanga;Stouffer, ed., Daniel
物种相互作用和环境变化之间的相互作用对于成对相互作用是众所周知的，但对于多营养相互作用则不是很清楚。考虑到地球上大多数生物多样性是由体温取决于环境温度的外温带组成的，理解这种相互作用如何在温度变化的环境中持续是特别重要的。在这里，我们提出了一个基于特征的数学框架，用于研究三营养食物链如何在季节性环境中持续存在。我们报告了两个关键发现。首先，如果高营养水平的物种(例如顶级捕食者)比低营养水平的物种(例如基础资源)更适应冷，那么三营养相互作用的持久性就会增强，这是因为在有利的温度范围内，较低的温度最适温度、更宽的反应范围和更低的死亡率。重要的含义是，多营养相互作用的组装和持续要求处于低营养水平的物种在某种程度上不适应环境热环境，就像最近的入侵事件一样。第二，对热变化环境的差异敏感性为中间消费者和顶级捕食者之间的利益冲突提供了机制解释。同样的冷适应能力提高了消费者的能力，当罕见的情况阻止捕食者这样做的能力时。因此，对其热环境的良好适应使中间消费者能够更好地获得资源并避免捕食者。我们预测，冷适应的等级应该限制在给定的热环境中所能支持的营养水平的数量，而外温式食物链的长度应该随着纬度的增加而增加，因为更大幅度的季节性波动为物种提供了更多在其热最适条件上发散的机会。
The interplay between species interactions and environmental variation is well‐understood for pairwise interactions but not for multi‐trophic interactions. Understanding how such interactions persist in a thermally variable environment is particularly important given that most biodiversity on the planet consists of ectotherms whose body temperature depends on the environmental temperature.Here we present a trait‐based mathematical framework for investigating how tri‐trophic food chains persist in seasonal environments. We report two key findings.First, the persistence of the tri‐trophic interaction is enhanced if species at upper trophic levels (e.g. top predators) are more cold‐adapted than those at lower levels (e.g. basal resources) by virtue of lower thermal optima, wider response breadths and lower mortality within the favourable temperature range. The important implication is that the assembly and persistence of multi‐trophic interactions requires that species at lower trophic levels be somewhat maladapted to their ambient thermal environment, as in the case of recent invasions.Second, differential sensitivity to thermally varying environments provides a mechanistic explanation for the conflict of interest between the intermediate consumer and top predator. The same cold‐adaptations that increase the consumer's ability to increase when rare deter the predator's ability to do so. Thus, being well‐adapted to its thermal environment makes the intermediate consumer better able to acquire resources and avoid predators.We predict that the hierarchy in cold‐adaptation should constrain the number of trophic levels that can be supported in a given thermal environment, and that ectotherm food chain lengths should increase with increasing latitude because larger‐amplitude seasonal fluctuations generate more opportunities for species to diverge in their thermal optima.