Myth and reality of the global pollination crisis

M.A. AIZEN, L.A. GARIBALDI , L.D. HARDER, S.A. CUNNINGHAM YA.M. KLEIN

Buenos Aires

Conferencia; Apimondia; 2011

Apimondia

There is mounting evidence that pollinators are declining as a result of widespread environmental degradation. As it has been proposed that a sizable proportion of the human diet depends directly or indirectly on animal pollination, the prospect that a global pollination crisis currently threatens agricultural productivity has drawn intense recent interest among scientists, politicians, and the general public. However, how much evidence is for the proposed food crisis? We used data from the Food and Agriculture Organization (FAO) to address this issue. First, even though it is still not possible to establish a global trend of change in the diversity and abundance of wild bees, the FAO dataset reveals that the global population of managed honey-bee hives has not declined but increased by about 50% during the last half century. Second, because of incomplete dependency on pollinators of most pollinator-dependent crops, our analysis showed that global production would decrease at most by only 6% in the absence of bees. Lastly, we demonstrated that the average yield of pollinator-dependent crops has increased steadily during recent decades, as have those of non-dependent crops, with no sign of slowing down. Overall, we conclude that simplistic claims of a global crisis in agricultural pollination are untrue. However, pollination problems may be looming. Despite pollinators are responsible for a minor fraction of global agriculture production, this fraction has increased by about 400% outpacing the growth in the global population of domesticated honey bees. Crops that depend on pollinators also account for most of the expansion in cultivated land occurring during the last 50 yrs. If the trend towards favouring cultivation of pollinator dependent crops continues, the need for the service provided by wild pollinators in decline due to extensive habitat destruction will greatly increase in the near future. So although the current pollination crisis is largely mythical, we may soon have a real one on our hands.