Tending to California's Tallest Trees

Guardian Weekly, UK

Not only is the coast redwood the world's tallest tree, it's also one of the most ancient. Having long populated the earth in swathes, now only two forests remain along the fog belt on the coast of California; over the past 150 years the number of redwoods has been further diminished by logging and property development. Ruskin Hartley, who works with Save-the-Redwoods League to turn forested areas into protected parkland so that people can continue to come and enjoy them, explains the uniqueness of these trees and the challenges that face them

Wednesday January 9th 2008

Looking up at the high canopies of the redwoods. Photograph: Ruskin Hartley

The coast redwood is the world’s tallest tree. What’s special about it is not just its size (redwoods grow up to 116 metres tall, which is like a 38-story building), it’s their longevity: a redwood can live for up to 2,200 years.

As a species, they trace their ancestry back 150-200m years, when they were much more widely distributed across the globe. You can find fossil remnants of the redwoods’ ancestors across North America and Europe. These days they are restricted to two populations here in California: coast redwood and giant sequoia; and one in China: the dawn redwood.

Despite studies and explorations of the redwoods for the better part of 150 years, a lot remains unknown. Why there are vastly fewer now than there were before, for instance. Over the past 200m years, as the world changed, perhaps the environment wasn’t so kind to them.

Coast redwoods trees grow on the California coastline where they need the winter rains and summer fogs to provide them with water. For some of the trees, 40% of their water intake will come directly through fog drip during the otherwise dry summers.

The trees are enormous. Since the first European settlers strayed into the forests people have been awed and inspired by looking up into their lofty, cathedral-like reaches. When you’re a six-foot individual walking through the forest, it can feel like being an ant.

It wasn’t until maybe 15 years ago that people ascended into the redwood canopies and discovered a whole new ecosystem. The trees branch into a candelabra near the top; while there’s one trunk on the ground there might be 130 mini trees growing out of that. In the crooks and crannies of that very complex tree, there is a rich life system assembling with soil mats and ferns, and with other trees. It’s been referred to as a coral reef in the sky.

An amphibian called the arboreal wandering salamander lives for its entire life up in the crowns of the trees. Salamanders are commonly found in or around water, so it’s a mystery how they came to live in these trees. It’s now a specialist at tree life, having found a safe, nutrient-rich environment in which to thrive. The soil accumulates from the debris flow from the trees themselves, and the moisture creates deep soil mats on the limbs of the trees into which the salamander can burrow in the dry summer months.

The sad thing about the coast redwoods is that 150 or so years ago there was about 2m acres of ancient forest, but since then timbering and logging has reduced it to a fraction of its former self. Now only about 5% remains. The trees are different: instead of old, complex trees that might be 3 metres in diameter and 90 metres high, there is a young, relatively simple forest.

Most of the coast redwoods continue to be in private ownership – about 1m acres are owned by four timber companies. Ninety years ago the single greatest threat to the forest was logging. Ancient trees don’t recover after they’ve been chopped; which makes cutting in an ancient forest more like mining than a sustainable activity.

If you roll the clock forward, these days the redwoods are posed between two threats: on one hand resource extraction (aggressive logging), and on the other residential development and suburban sprawl as people find new places to live.

One of the opportunities that lie ahead is to work with timber companies to manage the forest in a more sustainable manner so that we can continue to produce a supply of wood locally, rather than importing it from the tropical rainforest or arboreal forests of Canada and Russia.

The forestry regulations here in California are among the strictest in the world: they require the timber companies to replenish the forest, but the classic long-term timber model (they say that they’ll take a long-term perspective) spans a mere 30 or 40 year time horizon. There is a disconnect between the human timescale and that of the forests, as 40 years is a fraction of the natural lifespan of these trees.

What Save-the-Redwoods League has done from the very beginning is develop a conservation plan to identify the places where our protection efforts should be focused. Rather than let a timber company cut the land down or a developer build on it, we negotiate a purchase on fair market value from the company or owner. We then donate that land to the state park system here in California or the national park system.

There are no laws in California that preclude harvesting an old-growth tree, and they continue to be chopped down. There are wood pirates out there, too. A redwood tree is extremely valuable: if you cut it down, mill it up and sell the timber it might be worth $60,000. There’s a relatively small percentage of ancient redwoods that remain in private ownership, but they continue to be at risk.

The immediate threat is the population. As it grows it expands into the forest, which disrupts the natural rhythm. Forest fires – a natural process that helps to regenerate the forest – now burn down people’s homes. It is only possible to protect the trees on a meaningful scale when parks and reserves are part of a broader protected landscape that is managed for multiple natural values.

The other challenge – and it’s hard to know precisely how it will pan out – is global climate change. When you have a tree that thrives on the summer fog it’s clear that reductions in that fog will affect the forest. In the Sierra Nevada, earlier snow melt will cause drought conditions in the summer and increase the risk of catastrophic fire. While it’s an area of keen concern, it’s as yet unknown what changes will take place in temperature and ocean current over the coming century.

On top of that, California has a budget crisis; it being one of the richest nations in the world and one of the richest states we still have problems managing public land. We’re expecting the state to announce a 10% budget cut. The California State Parks department has already suffered multiple budget cuts. A 10% cut, when you’ve been cut to the bone already, has a significant impact on the ability of the state to steward these lands and provide public access to them.

Save-the-Redwoods League has had a good start with the parks we’ve been creating, but there’s more work to be done to ensure that they are viable long-term. There’s also the challenge of protecting the larger landscapes around those parks, so that they’re connected and can function naturally rather than being isolated islands of trees surrounded by residential developments or aggressive logging.

Many of the members of our organisation describe visiting the redwood groves as a transformational experience. Having gone to the forest as a child with their family and stood in awe, they remember that feeling throughout their lives. It inspires them both to work with us to continue protecting the forests and, I think, causes people to think about their own actions as they go home, about what they can do to make the world around them a better place.

• Ruskin Hartley was talking to Anna Bruce-Lockhart. For more information on the redwoods, visit the Save-the-Redwoods League website, here.