The global pollination crisis: myth and reality

MARCELO A. AIZEN, LUCAS A. GARIBALDI, SAUL A. CUNNINGHAM AND ALEXANDRA M. KLEIN

Bredasdorp, Sud África

Conferencia; Fynbos Forum; 2009

SANBI

There is evidence that pollinators are declining as a result of local and global environmental degradation. As a sizable proportion of the human diet depends directly or indirectly on animal pollination, the issue of how decreases in pollinator stocks could affect global crop production is of paramount importance. Using the extensive FAO dataset, we compared 45-yr series (1961-2006) in yield, and total production and cultivated area of pollinator dependent and nondependent crops. We investigated temporal trends separately for the developed and developing world, because differences in agricultural intensification, and socioeconomic and environmental conditions might affect yield and pollinators. Since 1961 crop yield (Mt/ ha) has increased consistently at average annual growth rates of ~1.5%. Temporal trends were similar between pollinator dependent and nondependent crops in both the developed and developing world, thus not supporting the view that pollinator shortages are affecting crop yield at the global scale. We further report, however, that agriculture has become more pollinator dependent because of a disproportionate increase in the area cultivated with pollinator dependent crops. Despite pollinators are responsible for a minor fraction of global agriculture production, this fraction has increased by about 400% while the fraction that do not depend on pollinator has only increased by two-fold during the last five decades. If the trend towards favouring cultivation of pollinator dependent crops continues, the need for the service provided by declining pollinators will greatly increase in the near future.