Among the innumerous consequences of climate change, the continuing warming of the planet would lead to an increase in the number of smaller bees but a drop in the abundance of larger species such as bumblebees, revealed a research conducted by US-based scientists.

The study warns of potential “cascading” effects on plant pollination and across whole ecosystems due to climate crisis. “Our study suggests that climate-induced changes in temperature, snowpack and summer precipitation may drastically reshape bee communities,” reads the research, which studied more than 20,000 bees over eight years in an area of the Rocky Mountains.

The research -- published on Wednesday in the journal Proceedings of the Royal Society B -- was conducted in the sub-alpine region, which according to the scientists is “particularly vulnerable to climate change” due to warming spring temperatures and melting of snow. The authors of the research have said that larger-bodied bees, including families of bumblebees, leafcutters and mason bees, and comb-building cavity nesters would drop in abundance as mercury soars. On the other hand, the number of smaller, soil-nesting bees would increase if average temperature levels rise further.

With regard to bumblebees, the researchers said that “this group is more threatened under climate warming than other bees in our system”. While this research was conducted in a mountainous area, researchers say that the trend remains the same across different landscapes in the United States. "Bumblebees’ body size and nest behaviour could also make them more vulnerable in a warming world," said researchers. This conclusion has also been drawn by several other studies that point out lower heat tolerance among bumblebees as compared to other bees.

A decline in the number of larger bees, which tend to fly further for food, would lead to a reduction in longer-distance pollination. This assumes significance as 75 percent of 115 top global food crops, including cocoa, coffee, almonds and cherries depend on animal pollination, according to a 2019 United Nations report. This report concluded that nearly half of all insect species worldwide are in decline and a third could disappear altogether by century’s end and the major causes behind their extinction are habitat loss and the use of pesticides.

(Edited by : Sudarsanan Mani)