Graph: Standing crop of open flowers
Slide 17 of 21
Notes:
(Model insights:)
I ran the model over a hypothetical season for a series of bee population
sizes and found that the standing crop of open flowers over time fit a
pattern very close to what I had been observing in the field. Standing crop
increases rapidly to a peak, then decreases more slowly. The peak standing
crop is lower as the number of introduced bees increases. In addition, the
time it takes to completely pollinate the field decreases as the number of
introduced bees increases. This was precisely what growers had been
describing to me: more bees means faster pollination. This is the advantage
to using a large number of bees to pollinate the crop. It decreases the time
to complete pollination. Many growers try to put out enough bees to
pollinate flowers as quickly as they come into bloom during the peak of
bloom. That of course means they run out of flowers sooner.
(The values on the axes above for number of open flowers and for time are
only very rough estimates. They could vary depending on the initial values
put into the model. More important is the shape of the curves that are
generated in the model, i.e., the pattern of standing crop over time.)
To see a practical application of this conclusion go to "A
test to determine if you have enough bees in your field", slide show
Part 3.
Strickler, K. 1997. Flower production and pollination in Medicago
sativa L. Grown for seed: model and monitoring studies. In, K.W.
Richards, ed. Proc. Int’l Symp. on Pollination Acta Horticulturae
437, ISHS pp. 109-113. Fig. 4