Mother Nature is not into monoculture, and a new study of wild bees offers yet more proof of this fact.
According to new research, not only has monoculture such as almond farming almost wiped out wild bee populations in these areas (by destruction of habitat), it turns out the domesticated bees brought into to pollinate the almonds and other crops are much less active without wild bees to encourage greater movement and range.
The new study of wild honeybees was published online Monday in the academic journal Proceedings of the National Academy of Sciences.
New study of wild bees confirms shortage in critical agricultural areas
This new wild bee population study is the first of its kind on a national scale, comes in response to a federal effort focusing on honey bee colony collapses. The federal initiative called for a national assessment of wild honey bee populations, and setting aside at least seven million new acres of habitat for wild pollinators such as honeybees.
The map shows the areas where gap between abundance of wild bees and demand for pollination is greatest. The biggest gaps (shown in red) are found in regions where are high levels of single-crop cultivation. These areas include 139 counties in the Upper Great Plains, areas along the lower Mississippi River, and large swaths of Texas, California, Arizona and Washington.
“I think the reason why the Central Valley lights up so much is largely almonds,” explains Taylor Ricketts, co-author of the study and Gund Professor at the University of Vermont’s Rubenstein School of Environment and Natural Resources. “It’s a hugely valuable crop that’s been expanding like crazy, and it’s entirely dependent on pollinators.”
Although other crops such as tomatoes and pitted fruits are certainly part of California’s supply-demand gap, “but the one that is making the map so bright red is almond,” Ricketts noted.
California added about 140,000 acres of nut-bearing almond trees between 2008 and 2013, based on U.S. Department of Agriculture data. Of note, the almond industry spends close to $239 million a year to bring in over 1 million bee hives to pollinate the trees.
In undertaking the study, researchers gathered estimates of bee abundance from top entomologists, and developed a model of how many wild bees live and work on different types of land in the lower 48 states. The results of the modeling were spot-checked against data from smaller, local studies.
Then, applying a well-known database of land cover, the research team determined the change in bee abundance from 2008 to 2013. Finally, they mapped the relationship between relative abundance and the need for pollination based on the types of crops cultivated so the problem can be clearly seen to be one of supply and demand.
The data showed that the relative abundance of wild bees declined in 23% of the land area in the contiguous states over the five-year period.
The map can be considered to be a warning to growers that they are too dependent on commercial honey bees and should “diversify their portfolio,” Ricketts commented. “It could be a glimpse of the future for a lot of crops,” he continued. “It’s such an extreme and early case, where they’ve so intensified that there’s no habitat left for native bees. ”
Statement from study co-author
“Most people can think of one or two types of bee, but there are 4,000 species in the U.S. alone,” notes Ricketts. “Wild bees are a precious natural resource we should celebrate and protect. If managed with care, they can help us continue to produce billions of dollars in agricultural income and a wonderful diversity of nutritious food.”