Ecology. 2014 Jan;95(1):9-13. doi: 10.1890/13-0760.1.
Insect mutualisms can have disproportionately large impacts on local arthropod and plant communities and their responses to climatic change. The objective of this study was to determine if the presence of insect mutualisms affects host plant and herbivore responses to warming. Using open-top warming chambers at Harvard Forest, Massachusetts, USA, we manipulated temperature and presence of ants and Chaitophorus populicola aphids on Populus tremuloides host plants and monitored ant attendance and persistence of C. populicola, predator abundance, plant stress, and abundance of Myzus persicae, a pest aphid that colonized plants during the experiment. We found that, regardless of warming, C. populicola persistence was higher when tended by ants, and some ant species increased aphid persistence more than others. Warming had negligible direct but strong indirect effects on plant stress. Plant stress decreased with warming only when both ants and C. populicola aphids were present and engaged in mutualism. Plant stress was increased by warming-induced reductions in predator abundance and increases in M. persicae aphid abundance. Altogether, these findings suggest that insect mutualisms could buffer the effects of warming on specialist herbivores and plants, but when mutualisms are not intact, the direct effects of warming on predators and generalist herbivores yield strong indirect effects of warming on plants.
昆虫共生关系对当地节肢动物和植物群落及其对气候变化的响应可能会产生不成比例的巨大影响。本研究的目的是确定昆虫共生关系是否会影响宿主植物和食草动物对变暖的反应。我们在美国马萨诸塞州哈佛森林的开顶式加热室中操纵温度以及蚂蚁和 Chaitophorus populicola 蚜虫在杨树宿主植物上的存在，并监测蚂蚁的出勤情况和 C. populicola 的持久性、捕食者的丰度、植物的应激和害虫桃蚜 Myzus persicae 的丰度，桃蚜在实验期间会在植物上定殖。我们发现，无论是否变暖，当蚂蚁照顾时，C. populicola 的持久性更高，一些蚂蚁物种比其他物种更能增加蚜虫的持久性。变暖对植物应激有直接的微小影响，但有很强的间接影响。只有当蚂蚁和 C. populicola 蚜虫都存在并参与共生时，植物应激才会随着变暖而减少。变暖通过减少捕食者的丰度和增加 M. persicae 蚜虫的丰度，增加了植物应激。总的来说，这些发现表明昆虫共生关系可以缓冲变暖对专食性食草动物和植物的影响，但当共生关系不完整时，变暖对捕食者和广食性食草动物的直接影响会对植物产生强烈的间接影响。
