Declining Wild Bee Populations Impact Pollinator-Dependent Crops

Summary: Declining wild bee populations, which are the result of habitat loss and of intensive agriculture, impact pollinator-dependent crops in thirteen states.

Map of Status of Wild Bee Abundance for 2013 ~ yellow = relatively low abundances; blue = higher abundances: Insu Koh et al./PNAS (DOI number 10.1073/pnas.1517685113), usage restrictions: with coverage of associated story and credit to PNAS, via EurekAlert!

Declining wild bee populations acknowledge inhospitable diseases, habitats, pesticides and weather in pollinator-dependent and pollinator-independent croplands, according to research published online Dec. 22, 2015, in Proceedings of the National Academy of Science.

The seven co-investigators and co-writers base their findings upon analysis and interpretation of data regarding land use and declining wild bee populations between 2008 and 2013. The study considers 44th U.S. President Barack Obama’s Memorandum June 20, 2014, Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators. Its authors developed the research plan advanced by the 2014 memorandum and by the Pollinator Health Task Force’s Pollinator Research Action Plan report May 19, 2015.

The study estimates declines in 139 counties.

One researcher at Pennsylvania’s Franklin and Marshall College and two each at Michigan State University, University of California (Davis) and University of Vermont finalized the map.

The map gives wild bee populations 23 percent declines in agricultural regions that claim 39 percent of the pollinator-dependent croplands in the United States of America. The 139 counties host almonds, apples, blueberries, cherries, honeymelons, peaches, pears, plums, pumpkins, squashes, tomatoes and watermelons and less pollinator-dependent canola, corn, cotton, soybeans and wheat. They involve the midwestern, northwestern, southern and western states of California, Illinois, Kansas, Louisiana, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Texas, Washington and Wisconsin.

Conversion of habitat into biofuel-producing farmlands joins other pollinator-unfriendly effects of intensive agriculture.

Uncultivated land keeps converting to corn for biofuel production compliance with the Energy Policy Act of 2005 and the Energy Independence and Security Act of 2007. Taylor Ricketts, professor at the University of Vermont in Burlington and senior co-author, links the severest declines in wild bees with 200 percent increases in corn-planting. Corn makes it to the market as an edible and as an ingredient of ethanol, which must represent at least 10 percent of all gasoline sold.

Neal Williams, associate professor in Davis, California, and study co-designer, notes of habitat loss and land reconfiguration: “We see striking mismatches in many places between the demand for pollination and the ability of wild pollinators to support that need.”

Chemicals, disease and habitat loss offer dire scenarios for the 4,000 wild bee species that pollinate edible and ornamental crops in the United States of America. The results of the study prompt Rufus Isaacs, entomologist at Michigan State University in Lansing and study co-author, to observe that “Our results highlight the need for strategies to maintain pollinator populations in farmland, and the importance of conservation programs that provide flowering habitat that can support wild bees and other pollinators.”

Research team members organized by lead author Insu Koh of the Gund Institute for Ecological Economics at the University of Vermont in Burlington question eco-system sustainability. They reiterate support for the federal government’s five-year, government-guided, pollinator-friendly, 7-million-acre (2,832,799.5-hectare) conversions.

Bee abundance on cropland weighted by crop area's pollinator dependence at a county scale for 2013: Insu Koh et al./PNAS (DOI: 10.1073/pnas.1517685113), usage restrictions: with coverage of associated story and credit to PNAS, via EurekAlert!

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

wild bee abundance: Insu Koh et al./PNAS (DOI number 10.1073/pnas.1517685113), CC BY 2.0, via EurekAlert! @ http://www.eurekalert.org/multimedia/pub/105645.php?from=314797

139 at-risk counties: Insu Koh et al./PNAS (DOI: 10.1073/pnas.1517685113), CC BY 2.0, via EurekAlert! @ http://www.eurekalert.org/multimedia/pub/105644.php?from=314797

For further information:

Dunham, Will. 21 December 2015. “Wild Bee Populations Dwindle in Main U.S. Crop Regions: Study.” Reuters > Tech > Science.
Available @ http://www.reuters.com/article/us-science-bees-idUSKBN0U42J220151222

Here & Now @hereandnow. 22 December 2015. "A new @uvmvermont study puts data about shrinking wild bee populations 'on the map.'" Twitter.
Available @ https://twitter.com/hereandnow/status/679466498738405376

Pollinator Research Action Plan: Report of the Pollinator Health Task Force. May 19, 2015.
Available @ https://www.whitehouse.gov/sites/default/files/microsites/ostp/Pollinator%20Research%20Action%20Plan%202015.pdf

Scalise, Joseph. 22 December 2015. “Wild Bee Populations Declining Across Main U.S. Crop Regions.” Science Recorder > News Ticker.
Available @ http://www.sciencerecorder.com/news/2015/12/22/wild-bee-populations-declining-across-main-u-s-crop-regions/

Stone, Emely. 22 December 2015. “Wild Bee Populations Dwindle in Main United States Crop Regions.” Chronicle Daily > Science.
Available @ http://chronicledaily.com/2015/12/22/wild-bee-populations-dwindle-in-main-united-states-crop/

The White House Office of the Press Secretary. 20 June 2014. "Presidential Memorandum – Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators." Briefing Room > Presidential Actions > Presidential Memoranda.
Available @ https://www.whitehouse.gov/the-press-office/2014/06/20/presidential-memorandum-creating-federal-strategy-promote-health-honey-b

wochit News. 21 December 2015. "Study Says Wild Bee Numbers Are on the Decline." YouTube.
Available @ http://www.youtube.com/watch?v=G4rn4sjE48k