Species-environment interactions changed by introduced herbivores

Summit areas of oceanic islands constitute some of the most isolated ecosystems on earth and are highly vulnerable to climate change and introduced species. Within the unique high-elevation communities of Tenerife (Canary Islands), reproductive success and thus the long-term survival of species may depend on environmental suitability as well as threat by introduced herbivores. In a recent ‘Editor’s Choice’ article published in AoB PLANTS, Seguí et al. studied the fitness of an endemic and vulnerable violet species along its altitudinal range (2,400 m – 3,500 m), and found it to be mainly affected by inter-annual and microhabitat variability along the gradient, especially at the lowest edge. Despite the increasingly adverse environmental conditions, the plant showed no pollen limitation with elevation, which was attributed to the increase in selfing and decrease in competition for pollinators at higher elevations. Plant fitness was extremely reduced owing to the presence of non-native rabbits, which changed plant trait–environment interactions along the gradient, threatening the survival of this violet.