Plant–pollinator network change across a century in the subarctic
Leana Zoller, Joanne M. Bennett, Tiffany M. Knight
Abstract
Animal-mediated pollination is a vital ecosystem service to crops and wild plants, and long-term stability of plant–pollinator interactions is therefore crucial for maintaining plant biodiversity and food security. However, it is unknown how the composition of pollinators and the structure of pollinator interactions have changed across longer time spans relevant to examining responses to human activities such as climate change. We resampled an historical dataset of plant–pollinator interactions across several orders of pollinating insects in a subarctic location in Finland that has already experienced substantial climate warming but little land use change. Our results reveal a dramatic turnover in pollinator species and rewiring of plant–pollinator interactions, with only 7% of the interactions shared across time points. The relative abundance of moth and hoverfly pollinators declined between time points, whereas muscoid flies, a group for which little is known regarding conservation status and responses to climate, became more common. Specialist pollinators disproportionately declined, leading to a decrease in network-level specialization, which could have harmful consequences for pollination services. Our results exemplify the changes in plant–pollinator networks that might be expected in other regions as climate change progresses. The authors resample a plant–pollinator network that was initially characterized by a naturalist in the late nineteenth century in Finland. They find that only 7% of the original interactions persisted; generally, specialist pollinators disproportionally declined while generalist muscoid flies increased as the abundant pollinators.