Pollinator declines: reconciling scales and implications for ecosystem services

Abstract

Despite the widespread concern about the fate of pollinators and the ecosystem services they deliver, we still have surprisingly scarce scientific data on the magnitude of pollinator declines and its actual contribution to crop pollination and food security. We use recently published data from northeastern North America to show that studies at both the local and regional scales are needed to understand pollinator declines, and that species-specific responses to global change are broadly consistent across scales. Second, we show that bee species that are currently delivering most of the ecosystem services (i.e. crop pollination) are not among the species showing declining trends, but rather appear to thrive in human-dominated landscapes.

Figure 1.. Trend in bee species' relative abundance in northeastern North American calculated over the period 1870–2011.

A) For species that either became locally extinct or persisted in Carleville, Illinois. B) For species that either are not ecosystem-service providers to crops (non-ESP), are at least occasionally ecosystem-service providers to crops (ESP), or are among the species cumulatively responsible for 90% of the pollinator visitation to at least one crop (main ESP). Regional data from Bartomeus et al. , local data from Burkle et al. and crop pollinator data from Garibaldi et al. .