Giant Sequoias Growing Tall in England

California’s giant trees have a new habitat across the globe.
What does this imply about geographic distribution?

 

Giant sequoias (Sequoiadendron giganteum), the most massive living things on earth, larger than whales and sauropods, are considered an endangered species in their isolated groves in California. These redwoods are treasured for their beauty and grandeur, and many are rightly protected in national and state parks. Their thick bark protects them from wildfires, allowing them to survive almost 3,000 years.

As majestic as the mature trees are, they grow from tiny seeds in relatively small cones. And though they are hardy survivors for millennia, they can only grow in suitable moist conditions.

This week, science reporters have described their transplantation to the UK over the last century and half, where they are doing very well. We can use this case to discuss geographic distribution, invasive species, fossils, climate change, deep time, and ecological history.

Giant sequoias are a rapidly growing feature of the UK landscape (University College London, 13 March 2024). This article introduces research conducted by University College London with colleagues at the Royal Botanic Gardens at Kew.

The new research, published in Royal Society Open Science, found that the most massive species of redwood trees, Sequoiadendron giganteum, known as the giant sequoia, can potentially pull an average of 85 kilograms of carbon out of the atmosphere per year. Though introduced to the UK 160 years ago, this is the first time the trees’ growth rate and resilience in the UK have been analysed.

Giant redwoods: World’s largest trees ‘thriving in UK’ (BBC News, 12 March 2024). Reporters Rebecca Morelle and Alison Francis focus mostly on the carbon-capturing ability of these giant trees, but share other interesting facts about their transplantation to the UK.

Giant redwoods – the world’s largest trees – are flourishing in the UK and now even outnumber those found in their native range in California.

The giants were first brought to the UK about 160 years ago, and a new study suggests they are growing at a similar rate to their US counterparts.

An estimated 500,000 trees are in the UK compared to 80,000 in California.

Half a million sequoias in England! That’s a surprise. Because they are young, the UK’s specimens have not attained the height of California’s native trees (yet), but they mature slowly after an early growth spurt. Because the UK specimens appear healthy, there’s no stopping them now.

The California groves in the Sierra Nevada mountains need specific habitat conditions like moisture near the surface, moderate temperatures and winter cold to thrive. The climate in England, without such high mountains, seems quite different, so it is surprising they are doing so well. Researchers studying their growth, though, feel that moisture in the UK is sufficient for their needs, and might even be better for them if the climate warms. The UK specimens do not appear to be reproducing on their own, so their numbers depend on humans to plant seedlings. In California, the small sequoia cones usually open after a fire has passed, to take advantage of cleared undergrowth.

The carbon-sequestering ability of giant sequoias was measured by Mathias Disney et al., who published their data in Dryad last May.

Giant sequoia trees are growing surprisingly quickly in the UK (New Scientist, 13 March 2024). Reporter Chen Ly states from the research paper that the UK sequoias are growing at about the same rate as their counterparts in California.

The trees also seemed to be growing just as quickly as those in California, capturing 85 kilograms of carbon from the atmosphere every year on average.

“That’s very quick,” says Disney. “Rather than having to wait 150 years for an oak tree to mature, giant sequoias become large within 50 years.”

Redwood trees are growing almost as fast in the UK as their Californian cousins – new study (The Conversation, 13 March 2024). In this article, lead author Mathias Disney discusses what his team found. He introduces the topic with a riddle:

What can live for over 3,000 years, weigh over 150 tonnes and could be sitting almost unnoticed in your local park? Giant sequoias (known as giant redwoods in the UK) are among the tallest and heaviest organisms that have ever lived on Earth, not to mention they have the potential to live longer than other species.

He claims that they “have evolved to be extraordinarily resilient” but he doesn’t know that; he deduces it from his assumption that everything evolved.

So how did these trees get here? Exotic plant collecting was big business in the 18th and 19th centuries, in large part as a display of wealth and taste. Giant sequoias were first introduced in 1853 by Scottish grain merchant and keen amateur collector Patrick Matthew, who gave them to friends. Later that same year commercial nurseryman William Lobb brought many more from California, along with accounts of the giant trees from which they came.

Giant sequoias quickly became a sensation and were planted to create imposing avenues, at the entrances of grand houses and estates, in churchyards, parks and botanic gardens.

As with most ecological zones, healthy forests need a variety of species. “If we value trees only as carbon sticks we will end up with thousands of hectares of monoculture,” Disney warns, “which isn’t good for nature.” But the British are proud of their giant sequoias.

Springboards for Discussion

It’s interesting that California hosts the most massive trees in the world (giant sequoias), the tallest trees in the world (coast redwoods), and the oldest trees in the world (bristlecone pines). We can use the news about these beautiful and majestic sequoia trees to explore some topics in science and natural history. You may wish to explore answers to these questions on your own or use them for a home schooling project.

Dating: How long could a sequoia live in theory under good conditions?

Dating: Why are no living trees older than a few thousand years?

Dating: How accurate is the dating of bristlecone pines? The oldest is said to be 5,000 years old. How do they determine the age? (Note: it’s not as simple as counting rings on one tree).

Distribution: Where else have fossil sequoias been found? (Hint: fossil sequoia trunks are on display at Florissant Fossil Beds in Colorado and in Yellowstone).

Distribution: Why are native sequoias so isolated now in California, if they can thrive across the world?

Adaptation: What traits allow giant sequoias to survive fires, insects and other hazards?

Biophysics: How do such tall trees get water and nutrients to the top from the roots?

Biophysics: Is there a height limit for a tree? What determines it? (link)

Taxonomy: How do coast redwoods (Sequoia sempervirens) differ from giant sequoias?

Taxonomy: Where is the dawn redwood (Metasequoia glyptostroboides) found today? Why was its discovery surprising?

Fossils: What geological layers contain fossil sequoias? How old did they get at maturity?

Fossils: What plants and animals are associated with fossil sequoias? Does the ecosystem differ from that around living sequoias?

Ecology: Describe the ecosystem of a single sequoia tree, from ground level to top of the canopy. What animals and plants benefit from sequoias?

Ecology: As a scientist, how would you investigate the top of a giant sequoia?

Ecology: What makes a transplanted species an invasive species instead of a welcome guest?

Climate: Did California’s giant sequoias endure previous bouts of global warming? Why are they threatened now?

Climate: Does the carbon sequestration of living sequoias reach a steady state with fallen logs that release CO₂ back into the atmosphere?

History: Who was Patrick Matthew, the man who first brought sequoias to Scotland? What was his connection with Darwin’s theory of evolution? (link)

History: What persons used fallen sequoia logs to live in?

History: What happened to one sequoia that had a tunnel made through its trunk for cars to drive through?

History: What was the reaction of visitors when a sequoia stump was transported and reconstructed at the Chicago World’s Fair in 1897?

History: What poet wrote “Poems are made by fools like me, but only God can make a tree”? Find the whole poem and learn about the author.

Ethics: What mentality led loggers in the 1800s to cut down sequoias? A trunk in Kings Canyon National Park was cut down for a dance floor!

Ethics: What led to the cessation of logging of giant sequoias?

Ethics: Discuss the proper stewardship of rare trees like sequoias. What are some criteria to propose a dividing line between legitimate use for human needs and protection?

Design: Do giant sequoias show evidence of intelligent design or irreducible complexity? Be specific.

Bible history: How soon after the Flood did the first sequoia trees sprout? Why in the Sierra Nevada mountains and not elsewhere?

Bible history: Did fossil sequoias grow before or after the Flood? If after, was there enough time for them to grow as big as they look?

Bible study: Find instances of “cedars” in the Psalm (e.g., Psalms 104, 148) and rewrite the verses in view of giant sequoias, or compose a similar psalm of your own (Note: Do not claim it is divinely inspired).

As a native Californian, I love our giant sequoias. Sadly, a handsome specimen planted in the town of Big Pine during the days of Theodore Roosevelt died in Sept 2020 from a combination of “not enough water, soil compaction, stress, and disease” (link). I used to admire it on trips up CA-395 to the mountains, but this one was out of its zone. Within their restricted habitat, groves of these trees are inspiring.

Visit Sequoia National Park if you can, and some of the other state and local parks that protect these magnificent trees. The Bible speaks well of trees. In Bible lands, the cedars of Lebanon were prized for their majesty and beauty. What do you think King David or Solomon would have written if they could have visited a stand of giant sequoias?