A Canadian study has set a new first, linking the decline of honey bees to climate change. The study, which spans 17 years, was conducted in the Rocky Mountains, where flower growth was not influenced by human activity or pesticide and herbicide use.
James D. Thomson, a professor and scientist working from the University of Toronto's Department of Ecology and Evolutionary Biology, studied the wild lily in the Rocky Mountains. In a press release issued by the University of Toronto, Thomson described his findings, saying “Early in the year, when bumble bee queens are still hibernating, the fruiting rates are especially low. This is sobering because it suggests that pollination is vulnerable even in a relatively pristine environment that is free of pesticides and human disturbance but still subject to climate change.”
Thomson's research, Flowering phenology, fruiting success and progressive deterioration of pollination in an early-flowering geophyte, was published in Philosophical Transactions of the Royal Society B: Biological Sciences this week. The issue is not so much that of bee decline meaning less pollination is occurring, but rather “... a climate-driven mismatch between the times when flowers open and when bees emerge from hibernation is a more important factor.”
Speaking to the Globe & Mail, Thomson said “Early in the year, when bumblebee queens are still hibernating, the fruiting rates are especially low. The bees tend to be doing less and less pollination.” Thomson went on to say that while he was only studying bumblebees, because honey bees don't live in the Rockies where he conducted his studies, "I’m closer to a smoking gun than anybody else." Thomson said his report "... is the first to produce “long-term evidence of a downward trend.”"
Speaking to the Montreal Gazette, Thomson said his findings, while limited to one species of bee and one type of flower, had greater implications for the world. A decline in pollination could result in declining food and fruit production, as well the potential loss of plants through extinction. Other scientists, however, believe that honey bees and other pollinators will be able to change their patterns to adapt to the earlier start to the growing season that climate change appears to be creating.
The New Scientist interprets Thomson's study somewhat differently, pointing to the fact that the bumblebee population Thomson studied was not in decline throughout the 17 years of his study. The New Scientist also said Thomson's study showed that climate change was not impacting pollination rates, saying the decline in pollination is puzzling.
Earlier research conducted by beekeeper and former NASA scientist, Wayne Esaias, showed that the early blooming flowers that most honeybees rely on to break their winter fast are blooming two weeks earlier than normal on average. According to an article in the John Hopkins Magazine, those first blooms are also the most productive, normally the time when honeybees bring home the most nectar.
Esaias thought the trend was caused by climate change, and also hypothesized that the earlier springs were the main reason for Colony Collapse Disorder, the unexplained death of bee colonies. Colony Collapse Disorder has caused a global decline in the honeybee population since 2006 when the disorder was first noticed.
While Thomson's research appears to go far in proving earlier theories about climate change, other scientists hesitate to make broad statements based on Thomson's results. A report in The Guardian quoted a UK scientist as saying Thomson's study was too limited to provide definite proof of a link between climate change and a decline in bee pollination. The Guardian went on to say Thomson conceded his "research was weak," defending his work saying, "'It certainly suggests that people who have warned about the possible climate-change consequence of dislocated timing between interacting species have made a reasonable argument."