Phenological shifts alter the seasonal structure of pollinator assemblages in Europe.

F Duchenne,M Pollet,C Fontaine,M Persson,M Elias,E Thébault,D Michez,J S Rousseau-Piot,M Drake,P Vanormelingen

doi:10.1038/s41559-019-1062-4

Abstract

Pollinators play an important role in terrestrial ecosystems by providing key ecosystem functions and services to wild plants and crops, respectively. The sustainable provision of such ecosystem functions and services requires diverse pollinator communities over the seasons. Despite evidence that climate warming shifts pollinator phenology, a general assessment of these shifts and their consequences on pollinator assemblages is still lacking. By analysing phenological shifts of over 2,000 species, we show that, on average, the mean flight date of European pollinators shifted to be 6 d earlier over the last 60 yr, while their flight period length decreased by 2 d. Our analysis further reveals that these shifts have probably altered the seasonal distribution of pollination function and services by decreasing the overlap among pollinators' phenologies within European assemblages, except in the most northeastern part of Europe. Such changes are expected to decrease the functional redundancy and complementarity of pollinator assemblages and, therefore, might alter the performance of pollination function and services and their robustness to ongoing pollinator extinctions.

Highlights

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not
Our results show that flower visitor responses to climate warming depend on their evolutionary history, geographical location and seasonal earliness
For most parts of Europe, the observed modifications of the seasonal structure of pollinator assemblages are expected to have negative consequences on pollination, while in northeastern Europe they might have positive effects on pollination as they result in an increased phenology overlap, both within and among pollinator orders (Fig. 3)

Summary

Introduction

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. Our analysis further reveals that these shifts have likely altered the seasonal distribution of pollination function and services by decreasing overlap among pollinators’ phenologies within European assemblages, except in the most northeastern part of Europe. Birds, amphibians and insects reveal that on average various phenological events - such as flowering or initiation of flight season – take place earlier in the season than in the past decades because of climate warming[1] Despite this general trend, a substantial inter-specific variation is observed in these responses, spatially[2] (e.g. across latitudes), and temporally[2,3] (e.g. spring versus summer species). This heterogeneity in species responses together with the fact that most studies focus on taxonomic rather than functional groups[1] challenges our ability to assess the consequences of phenological shifts for the functioning of communities and ecosystems across large spatial scales

Methods

Results

Conclusion