Giant sequoias, the largest trees on Earth, are thriving in Britain, growing at a rate nearly equivalent to those found in their native range in the U.S. state of California, researchers said on Wednesday.

Introduced to British country estates as a 19th-century status symbol, there are now an estimated half a million sequoias, also known as the giant redwoods, in the country, compared with 80,000 in California's Sierra Nevada mountains.

California's specimens are under threat from more frequent and intense wildfires and climate-change fuelled droughts.

But a report by Britain's academy of sciences, the Royal Society, showed that giant sequoias in Britain are generally doing well.

"In the UK our climate is more temperate, wetter, and so it is actually likely better suited to these trees in the long run," said Dr Mathias Disney from University College London, one of the authors of the study.

The giant sequoias can live for more than 3,000 years and were originally introduced to Britain around the 1800s, where they were planted in the grounds of grand estates, becoming a Victorian-era symbol of wealth due to their rarity.

Disney said giant sequoias grow fast, provide shade and benefits such as absorbing carbon, but it is not yet known how good they are for the native biodiversity.

"There are a surprising amount of these trees in the UK, and they are doing very well in terms of their growth," Disney told Reuters. "We shouldn't take them for granted even if they are relatively recent introduced species."