Global warming causing early plant blooms

Scientists in the UK on Wednesday said rising temperatures were causing some plants to flower almost a month earlier, which poses a risk of frost damage and disrupted feeding cycles for animals. 

A study done by researchers at the University of Cambridge observed more than 400,000 bloom recordings of 406 tree, shrub, herb and climbing plant species across the United Kingdom. They found the average date of first flowering between 1987 to 2019 is 30 days earlier than the average date from 1753 to 1986.

The flowering patterns were kept in a database called "Nature's Calendar," which contains observations by scientists, naturalists, and amateur and professional gardeners going back over 200 years.  

The results are "truly alarming" because of the ecological threats posed by early flowering, said professor Ulf Büntgen, who led the research.

Büntgen added that springlike weather in the UK could become more common in the wintry month of February if global temperatures continue to increase at the current rate. This rapid change in cycles could have an impact on forests, farms and gardens. 

What are the risks of early plant flowering?

A late frost can kill or damage a plant that blossoms too early. However, researchers said the greatest threat is to wildlife like birds and insects that have evolved their development stages in synchronicity with flowering patterns of plants they rely on for survival. 

If these cycles are no longer in phase, the result is called an "ecological mismatch."

"A certain plant flowers, it attracts a particular type of insect, which attracts a particular type of bird, and so on," Büntgen said in a press release. "But, if one component responds faster than the others, there's a risk that they'll be out of synch, which can lead species to collapse if they can't adapt quickly enough."

The biggest shift to earlier flowering, at 32 days, was found in herbs, which are able to undergo quick genetic adaptation. Büntgen said the change was "huge."

Büntgen said more data were needed to study the impacts of earlier flowering on the broader ecosystem. 

In January, the United Nations reported that the past seven years have been the hottest ever recorded, with the average global temperature in 2021 around 1.11 degrees Celsius (2.4 F) above the preindustrial levels.

wmr/sms (AFP, Reuters)