Climate influence on plant–pollinator interactions in the keystone species Vaccinium myrtillus

Background: Climate change is altering the world’s ecosystems through direct effects of climate warming and precipitation changes, but also indirectly through changes in biotic interactions. For instance, climate-driven changes in plant and/or insect communities may alter plant-pollinator interactions, thereby influencing plant reproductive success and ultimately population dynamics of insect-pollinated plants.
Methods: To better understand how the importance of insect pollination for plant fruit set varies with climate, we experimentally excluded pollinators from the partly selfing key-stone species Vaccinium myrtillus along elevational gradients in the forest-tundra ecotone in central Norway. The study comprised three mountain areas, seven elevational gradients spanning from the climatically relatively benign birch forest to the colder alpine areas above the tree line, and 180 plots of 1 x 1 m, with experimental treatments allocated randomly to plots within sites. Within the experimen...