Descombes Patrice, Pitteloud Camille, Glauser Gaëtan, Defossez Emmanuel, Kergunteuil Alan, Allard Pierre-Marie, Rasmann Sergio, Pellissier Loïc
Landscape Ecology, Institute of Terrestrial Ecosystems, ETH Zürich, 8092 Zürich, Switzerland.
Unit of Land Change Science, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland.
Science. 2020 Dec 18;370(6523):1469-1473. doi: 10.1126/science.abd7015.
Herbivory and plant defenses exhibit a coupled decline along elevation gradients. However, the current ecological equilibrium could be disrupted under climate change, with a faster upward range shift of animals than plants. Here, we experimentally simulated this upward herbivore range shift by translocating low-elevation herbivore insects to alpine grasslands. We report that the introduction of novel herbivores and increased herbivory disrupted the vertical functional organization of the plant canopy. By feeding preferentially on alpine plants with functional traits matching their low-elevation host plants, herbivores reduced the biomass of dominant alpine plant species and favored encroachment of herbivore-resistant small-stature plant species, inflating species richness. Supplementing a direct effect of temperature, novel biotic interactions represent a neglected but major driver of ecosystem modifications under climate change.
食草作用和植物防御沿着海拔梯度呈现出同步下降的趋势。然而，在气候变化的影响下，当前的生态平衡可能会被打破，动物的分布范围向上移动的速度比植物更快。在这里，我们通过将低海拔食草昆虫转移到高山草甸进行实验模拟了这种食草动物分布范围的向上移动。我们报告称，引入新的食草动物以及食草作用的增加破坏了植物冠层的垂直功能组织。通过优先取食具有与低海拔寄主植物相匹配功能性状的高山植物，食草动物减少了优势高山植物物种的生物量，并有利于抗食草的矮小植物物种的侵入，从而增加了物种丰富度。除了温度的直接影响外，新的生物相互作用是气候变化下生态系统变化的一个被忽视但主要的驱动因素。
