New research has shown that giant sequoia trees that were imported and planted in the United Kingdom (UK), some of which have been growing for as long as 160 years, are well adapted to their 'new' home. The study determined that the trees have growth rates in the UK that are similar to those found in their native range, which is in California. The trees are capturing also capturing huge amounts of carbon; it's estimated that one giant sequoia can absorb about 85 kilograms of carbon from the atmosphere every year. This is thought to be the first analysis of their tolerance and growth in the UK, and the findings have been reported in Royal Society Open Science.
Giant sequoias, also known as Sequoiadendron giganteum, are a massive species of redwood tree. Only about 80,000 are left in California, and they are considered endangered. There are roughly 500,000 redwoods in the UK, and they have widespread appeal so more are being planted.
"Giant sequoias are some of the most massive organisms on Earth and in their native range make up some of the most carbon-dense forests in the world due to their great age," said lead study author Ross Holland, formerly of the UCL Department of Geography and now at East Point Geo. "We hope that these findings can help guide decisions on future tree planting and management."
Although the best way to reduce the level of carbon in the atmosphere is to reduce the burning of fossil fuels, and we urgently need to do that to address climate change, trees can help offset some emissions if they are planted in the right areas. They can also provide other benefits, including to our mental health.
Giant sequoias are not as tall as coastal redwoods, but they are some of the largest organisms in the world, with massive trunks that grow quickly. They can live for 3,000 years or more, and grow as high as 90 meters (295 feet). They are also resistant to fire and can withstand intense blazes that kill other trees and plants.
In this study, the researchers took three-dimensional laser scans of 97 trees at different groves in the UK: Benmore Botanical Garden in Scotland, Kew in Sussex, Havering Country Park in Essex, and the Royal Botanic Gardens.
"Using the latest laser scanning technology has allowed us to accurately 'weigh' these massive trees without having to cut them down. This means we can measure many more trees as well as revisit them in the future," said study co-author Dr. Phil Wilkes, formerly of UCL and now at Royal Botanic Gardens, Kew.
The tallest tree in the survey was found to be 54.8 meters tall (180 feet), which is massive compared to most trees that are native to the UK. But, that is still a shorty compared to American sequoias, which are also much older.
Sources: University College London (UCL), Royal Society Open Science
