Monocultures

Country Bees vs City Bees

Did you know that bees often do better in urban areas than in the countryside because city parks and gardens have greater diversity of plant life than agricultural areas?[1]

This is a result of monocultures; an industrial method of farming that has taken the agricultural world by storm. A monoculture is defined as a field composed of a single crop species. This approach has significant economic advantages such as:

• reduced plant competition for resources
• control of undesirable (unprofitable) organisms
• reduction of costs by limitation of specific machinery required
• potential to maximize profit from growing high gross margin crops.[2]

However, monoculture farming has serious ecological implications because of its destruction of local biodiversity. Ontario holds a major portion of arable soils for Canada’s food production and in the past forty years there have been significant increases of land areas in monoculture.

A study done in Ontario by J. W. Ketcheson in 1980 determined that intensive cultivation and monoculture of land could have major effects on deterioration of soil and lower soil productivity in the long term.[3]  In spite of this, since 1980 monoculture practices have become increasingly prevalent on a local and global scale.

How exactly does the practice of monoculture affect bees?!

In large areas of monoculture, it determines what pollinating insects can forage.

Honeybees are the most widely used pollinators of monoculture crops and are certainly an integral aspect of their success. Unfortunately, this is not a mutually beneficial relationship and multiple studies have uncovered the detrimental effects of monocultures on the health of bees.

• Having only one type of pollen as a food source can lead to certain nutrient deficiencies[4] (the human equivalent would be eating only ONE food group)
• Certain crops have short ‘bloom times’ where nectar and pollen is only available for a short while[5]
• Some popular monoculture crops such as wheat and corn do not provide for the nectar or pollen needs of bees[6]
• Bees fed pollen from a range of plants had a healthier immune systemthan those dependent on monoculture diet
  •  Diversity in diet made bees better able to protect themselves and their larvae from microbes and pathogens[7]

What can be done?

A potential solution that is relatively simple is the idea of having ‘non-crop margins’ interspersed in large agricultural regions. The margins would managed to have native wildflower species to supplement the monoculture diet. [8]

---

[1] Richard Black, Environmental Correspondent. January 20, 2010. Bee decline linked to falling biodiversity BBC News Website. http://news.bbc.co.uk/2/hi/science/nature/8467746.stm

[2]University of Reading. Monoculture ECIFM. Accessed October 31, 2012. http://www.ecifm.rdg.ac.uk/monoculture.htm

[3] J.W. Ketcheson. 1980. Long-range effects of intensive cultivation and monoculture on the quality of southern Ontario soils. Canadian Journal of Soil Science. 60: 403-410

[4]  Brodschneider R. and K. Crailsheim. 2010. Nutrition and health in honey bees. Apidologie. 41: 278-294

[5] Decourtye A., Mader E. and N. Desneux. 2010. Landscape enhancement of floral resources for honey nees in agro-ecosystems. Apidologie. 41: 264-277.

[6]  Cane J. H. and V. J. Tepedino. 2001. Causes and Extent of Declines among Native North American Invertebrate Pollinators: Detection, Evidence and Consequences. Conservation Ecology. 5:1. [online] http://www.ecologyandsociety.org/vol5/iss1/art1/

[7] Alaux C., Ducloz F., Crauser D. and Y. Le Conte. 2010. Diet effects on honeybee immunocompetence. Biology Letters. 6: 562-565.

[8] Decourtye A., Mader E. and N. Desneux. 2010. Landscape enhancement of floral resources for honey nees in agro-ecosystems. Apidologie. 41: 264-277.