Climate change: UK trees bloom a month early due to warm weather

Weather of Arabia - Just as the fall of autumn leaves is delayed due to the continued warm weather at the beginning of autumn, flowers can appear early on trees and shrubs when the weather becomes warm before spring.

While some may welcome early flowering on trees, it is a phenomenon that carries many risks and indirect impacts on birds, insects and entire ecosystems, and this will have a significant impact on the “performance and productivity” of nature and agriculture.

In many places, global warming is causing spring to start early and fall to go late, and not all plants and animals can adapt at the same rate.

Scientists warn that if species get out of sync with one another, a concept known as ecological incompatibility, this could have disastrous consequences.

Pollen, nectar, seeds and fruits of plants are important food resources for insects, birds, and other wildlife. And if the flowers appear too early, they can be affected by frost, damaging the fruit tree crop.

A study looked at hundreds of thousands of observations of the first dates of flowering of trees, shrubs, herbs and climbing plants in an 18th-century database, known as the Nature Almanac, that covered the entire United Kingdom, from Shetland in the north and Northern Ireland in the west to Suffolk in the East.

The Cambridge researchers compared the first flowering dates of 406 plant species with climate records, and found that earlier flowering is closely related to rising global temperatures.

They found that the average first flower date from 1987 to 2019 was about a month earlier than the average first flower date from 1753 to 1986, and the grasses experienced the biggest shift, flowering 32 days earlier than they normally would.

Commenting on the research, which was published in the journal Proceedings of the Royal Society B, Dr John David, president of the Royal Horticultural Society in London, said plants flower earlier as a result of global warming, just as leaf fall is delayed in autumn due to warmer weather.