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Surprisingly few 'busy bees' make global crops grow

Date:
June 16, 2015
Source:
University of Vermont
Summary:
Surprisingly few bee species are responsible for pollinating the planet's crops, a major international study finds. Only two percent of wild bee species pollinate 80 percent of bee-pollinated crops worldwide, the researchers suggest.
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Only two percent of wild bee species pollinate 80 percent of bee-pollinated crops worldwide, researchers report. This study is one of the largest on bee pollination to date.
Credit: © serkucher / Fotolia

A major international study finds that surprisingly few bee species are responsible for pollinating the world's crops.

The paper, published in Nature Communications, suggests that only two percent of wild bee species pollinate 80 percent of bee-pollinated crops worldwide. The study is one of the largest on bee pollination to date.

While agricultural development and pesticides have been shown to produce sharp declines in many wild bee populations, the study shows these "busy bees" can remain abundant in agricultural landscapes.

The study gives a powerful economic rationale for conserving wild bees. It calculates the value of wild bee pollination to the global food system at $3,000 per hectare of insect-pollinated agricultural land, a number in the billions globally.

But the findings also offer a warning to conservation advocates hoping that economic arguments can justify the preservation of all species. Moral reasons are still needed, researchers say.

"This study shows us that wild bees provide enormous economic benefits, but reaffirms that the justification for protecting species cannot always be economic," says Taylor Ricketts of the University of Vermont's Gund Institute For Ecological Economics, a study co-author. "We still have to agree that protecting biodiversity is the right thing to do."

Background

Fifty-eight researchers worldwide conducted the three-year study, led by Prof. David Kleijn of the Netherlands' Wageningen University.

The study advances our understanding of wild bees' crucial role in the global food system. About two-thirds of the world's most important crops benefit from bee pollination, including coffee, cacao and many fruits and vegetables.

Wild pollination is increasingly important with the growing instability of honey bee colonies. Wild bees' agricultural value is now similar to that of honey bees, the study finds. Honey bees are no longer considered wild in many regions due to their intense management.

The most important wild bees for agriculture include some of the world's most common species, including the common eastern bumblebee (Bombus impatiens) in the U.S. and the red-tailed bumblebee (Bombus lapidarius) in Europe, researchers say.

One reason to preserve bee biodiversity is securing the future resiliency of global pollination systems, Ricketts says. Previous studies associate biodiversity with more stable pollination services over time.

"Species and populations can fluctuate significantly as landscapes and climates change," says Ricketts, who is also a professor in UVM's Rubenstein School of Environment and Natural Resources. "So protecting a wide variety of our wild bees is crucial."

The paper outlines bee-friendly practices for farmers, including maintaining wildflowers and grass strips, organic farming techniques, and limiting -- or delaying -- the use of pesticides and other chemicals.

Global collaboration

The study includes 90 individual studies of nearly 1,400 crop fields across five continents (North America, Europe, Asia, Africa and South America).

Regular monitoring found nearly 74,000 individual bees from nearly 785 wild bees species on crops. Of 20,000 known bee species, roughly two percent pollinated 80 per cent of crops.

"Rare and threatened species may play a less significant role economically than common species, but this does not mean their protection is less important," says Kleijn.

Ecosystem services

The economic benefits to people from nature -- such as crop pollination, water purification, and carbon storage -- are increasingly known as ecosystem services. The fact that nature provides these services has increasingly been used as a reason to protect the environment and its biodiversity.


Story Source:

Materials provided by University of Vermont. Original written by Basil D.N. Waugh. Note: Content may be edited for style and length.


Journal Reference:

  1. David Kleijn, Rachael Winfree, Ignasi Bartomeus, Luísa G Carvalheiro, Mickaël Henry, Rufus Isaacs, Alexandra-Maria Klein, Claire Kremen, Leithen K M'Gonigle, Romina Rader, Taylor H Ricketts, Neal M Williams, Nancy Lee Adamson, John S Ascher, András Báldi, Péter Batáry, Faye Benjamin, Jacobus C Biesmeijer, Eleanor J Blitzer, Riccardo Bommarco, Mariëtte R Brand, Vincent Bretagnolle, Lindsey Button, Daniel P Cariveau, Rémy Chifflet, Jonathan F Colville, Bryan N Danforth, Elizabeth Elle, Michael P.D. Garratt, Felix Herzog, Andrea Holzschuh, Brad G Howlett, Frank Jauker, Shalene Jha, Eva Knop, Kristin M Krewenka, Violette Le Féon, Yael Mandelik, Emily A May, Mia G Park, Gideon Pisanty, Menno Reemer, Verena Riedinger, Orianne Rollin, Maj Rundlöf, Hillary S Sardiñas, Jeroen Scheper, Amber R Sciligo, Henrik G Smith, Ingolf Steffan-Dewenter, Robbin Thorp, Teja Tscharntke, Jort Verhulst, Blandina F Viana, Bernard E Vaissière, Ruan Veldtman, Catrin Westphal, Simon G Potts. Delivery of crop pollination services is an insufficient argument for wild pollinator conservation. Nature Communications, 2015; 6: 7414 DOI: 10.1038/ncomms8414

Cite This Page:

University of Vermont. "Surprisingly few 'busy bees' make global crops grow." ScienceDaily. ScienceDaily, 16 June 2015. <www.sciencedaily.com/releases/2015/06/150616114040.htm>.
University of Vermont. (2015, June 16). Surprisingly few 'busy bees' make global crops grow. ScienceDaily. Retrieved May 8, 2017 from www.sciencedaily.com/releases/2015/06/150616114040.htm
University of Vermont. "Surprisingly few 'busy bees' make global crops grow." ScienceDaily. www.sciencedaily.com/releases/2015/06/150616114040.htm (accessed May 8, 2017).