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<dd>Aizen, M. A., L. A. Garibaldi, S. A. Cunningham, and A. M. Klein.
2009. How much does agriculture depend on pollinators? Lessons from
long-term trends in crop production. Ann Bot
<b>103</b>:1579-1588.<br><br>
</dl>Background and Aims: Productivity of many crops benefits from the
presence of pollinating<sup> </sup>insects, so a decline in pollinator
abundance should compromise<sup> </sup>global agricultural production.
Motivated by the lack of accurate<sup> </sup>estimates of the size of
this threat, we quantified the effect<sup> </sup>of total loss of
pollinators on global agricultural production<sup> </sup>and crop
production diversity. The change in pollinator dependency<sup> </sup>over
46 years was also evaluated, considering the developed<sup> </sup>and
developing world separately.<sup> <br><br>
</sup>Methods: Using the extensive FAO dataset, yearly data were compiled
for<sup> </sup>1961–2006 on production and cultivated area of 87
important<sup> </sup>crops, which we classified into five categories of
pollinator<sup> </sup>dependency. Based on measures of the aggregate
effect of differential<sup> </sup>pollinator dependence, the consequences
of a complete loss of<sup> </sup>pollinators in terms of reductions in
total agricultural production<sup> </sup>and diversity were calculated.
An estimate was also made of<sup> </sup>the increase in total cultivated
area that would be required<sup> </sup>to compensate for the decrease in
production of every single<sup> </sup>crop in the absence of
pollinators.<sup> <br><br>
</sup>Key Results: The expected direct reduction in total agricultural
production<sup> </sup>in the absence of animal pollination ranged from 3
to 8 %, with<sup> </sup>smaller impacts on agricultural production
diversity. The percentage<sup> </sup>increase in cultivated area needed
to compensate for these deficits<sup> </sup>was several times higher,
particularly in the developing world,<sup> </sup>which comprises
two-thirds of the land devoted to crop cultivation<sup> </sup>globally.
Crops with lower yield growth tended to have undergone<sup> </sup>greater
expansion in cultivated area. Agriculture has become<sup> </sup>more
pollinator-dependent over time, and this trend is more<sup>
</sup>pronounced in the developing than developed world.<sup> <br><br>
</sup>Conclusions: We propose that pollination shortage will intensify
demand for<sup> </sup>agricultural land, a trend that will be more
pronounced in the<sup> </sup>developing world. This increasing pressure
on supply of agricultural<sup> </sup>land could significantly contribute
to global environmental<sup> </sup>change.<br><br>
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<a href="http://aob.oxfordjournals.org/cgi/content/abstract/103/9/1579" eudora="autourl">
http://aob.oxfordjournals.org/cgi/content/abstract/103/9/1579</a></body>
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