Tuesday, January 4, 2011
It's not just honeybees that are in trouble
Could native bees disappear from our gardens?
Some disturbing news found its way into my Internet reading aggregator today. It seems that researchers have found that four common species of North American bumblebees have declined by as much as 96 percent in recent decades. Scientists believe that a combination of disease and loss of genetic diversity may be the main culprits in the disappearances.
We have known for several years that honeybee populations are in trouble as a result of the still mysterious colony collapse disorder, but I think many of us had felt rather smug in the knowledge that even if honeybees disappeared, we would still have our native bees to do the important work of pollination for us. It seems that our confidence may have been misplaced.
The fact that native bees like bumblebees, as well as honeybees, are in trouble is not something to be taken lightly. It is not only hobby gardeners who depend on the little critters. Food production right around the world would be seriously impacted by their decline. Fully 90% of the world's commercial crops including most fruits, vegetables, nuts, coffee, soya beans and cotton are all dependent on pollination by bees to maintain adequate yields. Moreover, bees are an important link in the food chain that sustains birds and other animals.
The findings of the decline are a result of a three-year study led by an entomologist from the University of Illinois. The study team tracked changing distribution, genetic diversity and pathogens in eight species of bumblebees in the U.S. By comparing findings with historical records, they were able to determine that four of the species had declined by up to 96% and also that their geographical ranges had decreased by from 23% to 87%.
Perhaps the most troubling of the findings concerned the loss of genetic diversity. Populations that lack genetic diversity are less able to adapt to changes and to fight off new diseases that pop up. They may even be less able to resist pollution or predators.
In summing up the study, its leader Sydney Cameron wrote: "Pollinator decline has become a worldwide issue, raising increasing concerns over impacts on global food production, stability of pollination services, and disruption of plant-pollinator networks. "
What can we as gardeners do to help?
Number one is to forego pesticides. Bees, butterflies and other pollinators are killed by these chemicals just as quickly and effectively as the "bad bugs".
Second, it is important to plant as wide a diversity of plants as possible in order to provide food for the pollinators over the longest possible period. It is also important to provide a shallow water source that the bees can drink from.
And third, try to provide appropriate nest sites and shelter for the insects. Just like any other animal, they need homes.
Too many wonderful animals are disappearing too fast from the earth. From tigers to penguins to fish, hundreds of species are in serious trouble from encroaching humanity, climate change, poaching and loss of genetic diversity. We may not be able to affect the fate of many of them, but perhaps we can do something to help the bees.