The impact of change in bee population on crop production
Using the NASS data to Measure the Impact of Bee Colony Collapse Disorder (CCD) on US Agriculture Gaetan Lion August 22, 2011 1
IntroductionThe Media has given extensive coverageon the bee Colony Collapse Disorder(CCD), a mysterious condition associatedwith a decimation of bee colonies duringthe mid 2000s. In turn, the Media hasconveyed the crisis it represents for USagriculture as many crops rely extensivelyon bee pollination. We will investigatethose assertions studying the NASS data. 2
The number of Bee Colonies Source: NASSWhile the Media has frequently mentioned loss of 30% per year in beecolonies starting in 2005, the NASS records show this is a wild exaggeration.Over the entire period, the loss has been less than 1% per year. 3
Annual % change in # of Bee Colonies Source: NASSThe drop in bee colonies in 2005 was nowhere near 30% (this supposedly massiveloss was attributed to CCD). Instead, it was only – 5.6%. When looking at thelonger data set going back to 1986, you see up and down cycles. And, the impactof CCD in 2005 looks more like an otherwise natural down cycle that was shortwhen compared with the 1991 – 1996 down cycle. 4
Hollywood’s really bad timing… Source: NASSThis documentary conveying a crisis “Vanishing of the Bees” came out in October2009, just as bee colonies experienced their most rapid 2-year growth in the historyof the disclosed NASS data (see ellipse in graph). A more accurate title for thisdocumentary would have been “Resurging Bees.” 5
Relation between Bees and Crops Source: NASSOut of seven major crops supposedly greatly dependent on bee pollination,four have a negative correlation with number of bee colonies, one has norelationship with bee colonies, and only two have a positive relationship withbee colonies. 6
An interesting case: Almonds Some crops, including…almonds, depends entirely on the honey bee… [Quote from ABF] The NASS data suggests something different. It would readily support that bees are bad for almonds. Given that this is botanically not the case, we have to conclude that if bees are so critical to almonds, we have far more bees than we need to grow almonds. And, that’s why the scatter plot could show a negative relationship between the two. How else could you explain it? 7
Another look at Bees vs AlmondsWe standardized the NASS data (# of bee colonies vs almond production) so wecould more readily compare the two data sets on a similar scale. One canobserve the perplexing strong negative relationship between the two. When beecolonies increase, almond production decreases and vice versa. 8
Another case: Cherries Some crops, including … cherries, are 90% dependent on honey bee. [Quote from ABF]. Again the NASS data is not supportive of the above ABF statement. Here the scatter plot illustrates a relationship between bees and cherry production that is fairly close to random. If we accept this is not botanically true, again this graph suggests we must have plenty more bees than we need to grow cherries. 9
Another look at Bees vs CherriesWe standardized the NASS data (# of bee colonies vs cherries production) so wecould more readily compare the two data sets on a similar scale. As is, one canreadily observe a random relationship between the two. 10
Conclusion• The bees are more resilient than the Media or the ABF convey. The CCD crisis is overhyped.• Bee colonies are in the midst of a resurgence (2009 & 2010). The Media has ignored this fact. It will pay attention to bees upon their next natural down cycle.• The relationship between bee colonies and crops relying on bees for pollination is not strong. This suggests there are more than enough bees to do the job. Thus, the next downturn in bee colonies should not cause a food shortage. 11
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