Global agricultural productivity is threatened by increasing pollinator dependence without a parallel increase in crop diversification

AIZEN, MARCELO A.; AGUIAR, SEBASTIÁN; BIESMEIJER, JACOBUS C.; GARIBALDI, LUCAS A.; INOUYE, DAVID W.; JUNG, CHULEUI; MARTINS, DINO J.; MEDEL, RODRIGO; MORALES, CAROLINA L.; NGO, HIEN; PAUW, ANTON; PAXTON, ROBERT J.; SÁEZ, AGUSTÍN; SEYMOUR, COLLEEN L.

GLOBAL CHANGE BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019 vol. 25 p. 3516 - 3527

1354-1013

The global increase in the proportion of land cultivated with pollinator‐dependent crops implies increased reliance on pollination services. Yetagricultural practices themselves can profoundly affect pollinatorsupply and pollination. Extensive monocultures are associated with alimited pollinator supply and reduced pollination, whereasagricultural diversification can enhance both. Therefore, areas whereagricultural diversity has increased, or at least been maintained,may better sustain high and more stable productivity ofpollinator‐dependent crops. Given that >80% of all crops depend,to varying extents, on insect pollination, a global increase inagricultural pollinator dependence over recent decades might have ledto a concomitant increase in agricultural diversification. Weevaluated whether an increase in the area of pollinator‐dependentcrops has indeed been associated with an increase in agriculturaldiversity, measured here as crop diversity, at the global, regional,and country scales for the period 1961?2016. Globally, results showa relatively weak and decelerating rise in agricultural diversityover time that was largely decoupled from the strong and continuallyincreasing trend in agricultural dependency on pollinators. Atregional and country levels, there was no consistent relationshipbetween temporal changes in pollinator dependence and cropdiversification. Instead, our results show heterogeneous responses inwhich increasing pollinator dependence for some countries and regionshas been associated with either an increase or a decrease inagricultural diversity. Particularly worrisome is a rapid expansionof pollinator‐dependent oilseed crops in several countries of theAmericas and Asia that has resulted in a decrease in agriculturaldiversity. In these regions, reliance on pollinators is increasing,yet agricultural practices that undermine pollination services areexpanding. Our analysis has thereby identified world regions ofparticular concern where environmentally damaging practicesassociated with large‐scale, industrial agriculture threaten keyecosystem services that underlie productivity, in addition to otherbenefits provided by biodiversity.p { margin-bottom: 0.25cm; line-height: 120%; }