Environmental degradation amplifies species' responses to temperature variation in a trophic interaction.
Environmental degradation amplifies species' responses to temperature variation in a trophic interaction.
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环境退化放大了物种对营养相互作用中温度变化的反应。
DOI：
10.1111/1365-2656.13069
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Mugabo M
中科院分区：
文献类型：
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作者：
Mugabo M
土地利用和气候变化是当前生物多样性危机的两个主要驱动因素。然而，我们缺乏对单物种和多物种关联如何受到多种环境压力之间相互作用的影响的理解。我们通过研究环境退化如何与每日随机温度变化相互作用来影响寄主-拟寄主营养相互作用中的个体生活史和种群动态来解决这一空白，研究对象是印度粉蛾（Plodia interpunctella）及其拟寄主canescens。我们进行了一个单代个体生活史实验和一个多代微观世界实验，在宿主资源退化的四个水平，存在或不存在寄生体的情况下，将个体和微观世界维持在26°C的平均温度下，该温度保持不变或随机变化。在个体水平上，资源退化均增加了幼鱼发育时间，减小了成虫体型。寄生蜂对温度变化的敏感性高于寄主，在中等退化环境中，寄生蜂的幼虫期短于恒温环境，成虫寿命长于恒温环境。资源退化还改变了寄主对温度变化的响应，导致资源退化程度高的幼体发育时间较长。在种群水平上，与不退化或资源高度退化相比，中度资源退化放大了温度变化对寄主和寄生蜂种群的影响，并且在波动温度下寄生蜂的总体丰度较低。寄生蜂自上而下的调节和资源退化自下而上的调节对寄主和寄生蜂种群对温度变化的响应有50%以上的影响。我们的研究结果表明，环境退化可以通过直接和间接的性状介导效应强烈影响营养相互作用中的物种对短期温度波动的反应。这些影响是由物种对环境条件的敏感性差异驱动的，并调节自上而下（寄生）和自下而上（资源）的调节。这项研究强调需要考虑物种特征对环境压力的敏感性差异，以了解相互作用的物种如何对同时发生的人为变化做出反应。
Land‐use and climate change are two of the primary drivers of the current biodiversity crisis. However, we lack understanding of how single‐species and multispecies associations are affected by interactions between multiple environmental stressors.We address this gap by examining how environmental degradation interacts with daily stochastic temperature variation to affect individual life history and population dynamics in a host–parasitoid trophic interaction, using the Indian meal moth,Plodia interpunctella, and its parasitoid waspVenturia canescens.We carried out a single‐generation individual life‐history experiment and a multigeneration microcosm experiment during which individuals and microcosms were maintained at a mean temperature of 26°C that was either kept constant or varied stochastically, at four levels of host resource degradation, in the presence or absence of parasitoids.At the individual level, resource degradation increased juvenile development time and decreased adult body size in both species. Parasitoids were more sensitive to temperature variation than their hosts, with a shorter juvenile stage duration than in constant temperatures and a longer adult life span in moderately degraded environments. Resource degradation also altered the host's response to temperature variation, leading to a longer juvenile development time at high resource degradation. At the population level, moderate resource degradation amplified the effects of temperature variation on host and parasitoid populations compared with no or high resource degradation and parasitoid overall abundance was lower in fluctuating temperatures. Top‐down regulation by the parasitoid and bottom‐up regulation driven by resource degradation contributed to more than 50% of host and parasitoid population responses to temperature variation.Our results demonstrate that environmental degradation can strongly affect how species in a trophic interaction respond to short‐term temperature fluctuations through direct and indirect trait‐mediated effects. These effects are driven by species differences in sensitivity to environmental conditions and modulate top‐down (parasitism) and bottom‐up (resource) regulation. This study highlights the need to account for differences in the sensitivity of species’ traits to environmental stressors to understand how interacting species will respond to simultaneous anthropogenic changes.