Altering Agricultural Practices Improves Honey Bee Populations

Buri, P., Humbert, J. Y., & Arlettaz, R.  2014.  Promoting Pollinating Insects in Intensive AgriculturalMatrices: Field-Scale Experimental Manipulation of Hay-Meadow Mowing Regimes and Its Effects on Bees.  Public Library of Science ONE 9(1):  1-12.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0085635

Honey bees (Apis mellifera) provide a crucial ecosystem service by pollinating flowering plants.  This service is mutually beneficial to agricultural professionals and the ecosystem within the range of the bees.  However, honey bees do not only provide a service, but they require ample stores of pollen in order to survive.  If these stores are greatly altered over the course of an agricultural season, the honey bees suffer the consequence.  Farmers need to clear cut hay meadows in order to create bales and harvest a crop.  When this occurs, the entire field of hay honey bees feed upon is removed, and the bees are required to find an alternate food source within their range.  In order to quantify the effect of hay-meadow mowing techniques, Buri et al. 2014 performed a study.  Buri et al. 2014 hypothesized that honey bee numbers would decline sharply if their immediate food source, accessible to the hive, had suddenly been removed.  Contrarily, they hypothesized that honey bees would survive if an uncut hay refuge persisted after a mowing.

In order to test their hypotheses, Buri et al. 2014 implemented a study with three treatment methods on thirty-six hay fields on the Swiss Plateau (near European Alps).  A majority of the land in this region, upwards of 90 percent, serves agricultural purposes.  The control hay meadow was clear-cut after June 15 according to regulations.  The first experimental group was also cut after June 15, but 10-20 percent of the meadow was left as a refuge for bees. The other experimental group was delayed in mowing until after July 15, 2011.  Bees from hives adjacent to each experimental section were collected during the summer of 2011 and also in the subsequent year.  Buri et al. 2014 intended to determine both short and long term effects of agricultural techniques on the health of the bees.  Control groups showed a decline in bee numbers after the June 15 mowing.  Delayed mowing demonstrated a positive effect on honey bee health and numbers in the short term, but had similar long term effects to the control.  The optimal treatment for maintenance of honey bees was incomplete mowing.  The refuges allowed bees to persist both short and long term increasing hive health and therefore pollination output.

With this information, farmers around the world with any crop that relies on bee pollination can better manage their cropland.  By reserving refuges of plants for the honey bees, the bees are able to persist and maintain a healthy hive.  In return, the honey bees are capable of more adequately providing the farmers with the pollination ecosystem service.  This mutual relationship can allow farming to improve while also maintaining biodiversity by promoting pollinator species.