Martin-Luther University Halle-Wittenberg, Germany
Abstract: The majority of the world's plants rely on animal pollinators for reproduction, making pollination a key ecosystem service for the maintenance of natural and crop plant communities. Hence, maintaining the long-term stability of plant-pollinator interactions is critical to safeguarding biodiversity and food security. However, it is uncertain how pollinator composition and interaction structure has changed over longer time periods that are essential to understand responses to human actions such as climate change
We aimed to bridge this knowledge gap by re-examining a historic dataset on plant-pollinator interactions collected over 120 years ago at a subarctic site in Finland that has already experienced significant climate warming but little land use change.
Our findings suggest that pollinator composition and plant-pollinator interactions are highly dissimilar across the two time points. Specifically, the relative abundance of moth and hoverfly pollinators decreased over time, whereas muscoid flies, a group about which little is known concerning conservation status and response to climate change, increased.
Specialist species declined disproportionally, leading to a decrease of network-level specialization, with potential negative consequences for pollination service. Our results provide insights into variation in plant-pollinator interactions over long periods of time that are rarely explored, and could potentially serve as an indication of the changes in plant-pollinator networks that may occur in other areas of the world as climate change progresses.
