The Race to Save the Last Old-Growth Redwood Forests on Earth

Del Norte Coast Redwoods State Park is one of four parks that comprise Redwood National and State Parks. Collectively these four parks are a 133,000-acre United Nations-recognized World Heritage Site and International Biosphere Reserve, which contains some of the last old-growth redwood forests on earth.

According to Save the Redwoods League, coast redwoods like those in Del Norte Coast Redwoods State Park “can reach higher than a 30-floor skyscraper (more than 320 feet), so high that the tops are out of sight. Their trunks can grow more than 27 feet wide, about eight paces by an average adult person! Even more incredible: these trees can live for more than 2,000 years. Some coast redwoods living today were alive during the time of the Roman Empire.”

There are a number of ways in which conservationists in Del Norte Coast Redwoods State Park are working to restore these forests — which are only a five percent remnant of what the original old-growth forests were before logging — and one them is somewhat controversial.

“Where there are big trees, there are often big fish.”

Our team never thought of salmon as redwood forest residents until we started researching for our shoot in Del Norte Coast Redwoods State Park. According to a series of short films by California State Parks on forest restoration, the Smith River, whose major tributary, Mill Creek, runs through Del Norte Coast Redwoods State Park, is “the last and largest undammed river in California...world-renowned for being a salmon stronghold. It contains some of the healthiest populations of salmon, steelhead and cutthroat trout in California." 

“Where there are big trees, there are often big fish.”

The salmon who swim this park's sparkling streams provide food not only for birds, bears, insects and other fish, but also a nutritious fish fertilizer for redwoods and other trees via the decaying remains that these wildlife diners leave behind. In fact, in forests where salmon is plentiful, these decaying remains provide up to 75% of the nitrogen trees need.  

A major focus of redwood restoration in Del Norte Coast Redwoods State Park has been to restore the Mill Creek watershed, which is vital to the salmon population. The watershed is basically a drainage basin, and since water runs downhill, disturbances on higher ground — such as a century’s worth of logging — can cause great distress to the plants, trees and wildlife below.

For example, when logging was at its height, the logging companies were in the habit of clearing out woody debris from Mill Creek, which looked nice and tidy, but wasn’t nice at all for the salmon, who depend on that messy debris for their resting and hiding places. The clearing out of streams put the salmon population at risk, which in turn put the redwoods at risk.

Which is why California State Parks, along with such partners as Save the Redwoods League, the California Coastal Conservancy, The Smith River Alliance, the Department of Fish and Wildlife and the US Fish and Wildlife Service, raised $60 million to acquire the 25,000-acre Mill Creek property in 2002.

By acquiring this land and raising several million dollars more to restore the Mill Creek watershed — including putting back some wood into the streams so that salmon could have their resting and hiding places again — California State Parks and its partners have helped restore the salmon population, which is helping to restore the redwood population.

In addition, Del Norte Coast Redwoods State Park has removed many of the old dirt logging roads (there were 329 miles of logging roads that came with the Mill Creek property). These roads, which no longer serve a purpose, have also posed a threat to salmon and other aquatic creatures in the park because of serious erosion. This erosion of old logging roads coated the streambeds, which are salmon spawning grounds, with silt. In addition, heavy erosion and landslides caused turbidity currents, which are downstream currents that move rapidly due to the heavy weight of the silt they carry, thus creating passage impediments for salmon and other fish.

The Mill Creek Watershed project is the largest restoration project in California State park history, a project that will take decades and maybe even centuries to truly restore these forests. And yet the effects are already evident in the growth of Mill Creek’s coho salmon run, the flourishing of young trees and in the mitigation of flood risks.

The Smith River Alliance reports that, “Thanks to a grant from the Coastal Conservancy and contributions from State Parks and CDFW, the last significant man-made barrier to salmon migration in the 25,594 acre Mill Creek watershed has been removed. Over one kilometer of excellent spawning and rearing habitat was made available and was quickly colonized by coho salmon who had been regularly observed downstream of the barrier.”

Restore the Redwoods...With Logging?

It may sound counterintuitive, but environmentalists have in fact turned to logging as a means of restoring the redwoods. One of the consequences of a century of redwood logging is that Douglas firs have taken over much of the space that redwoods once occupied. Whereas the old forests had twenty to thirty redwoods per acre, redwood logging resulted in as many as 900 to 2,000 trees per acre taking their place — most of them Douglas fir. 

Logging dense stands of Douglas fir turns out to be a legitimate and effective way to make room for redwoods again and give young redwoods a chance to survive and thrive. It also prevents the overcrowded Douglas fir population from forming a canopy that will eventually become so dense that it blocks out sunlight from wildlife, plants and young trees below.

To restore the biodiversity of the old-growth redwood forests, it is necessary to replace the Douglas fir not only with redwoods, but also with other conifer and hardwood species. Dan Burgess, “a local community organizer and restoration practitioner” who manages Mill Creek’s tree restoration nursery, works to maintain the genetic integrity of the restoration site. “The seed source is…part of the genetic integrity program,” he says.  “We want to collect local material, find the source of the seed and the propagation material as close to the restoration site as possible. So that means within a mile, and if not within a mile, at least 800 feet in elevation from that site.”

By 2015, which was 13 years after the Mill Creek property was acquired, California State Parks asserted that “the restoration team had thinned 4,000 acres of forest, placed 1,000 logs back in streams, and removed 70 miles of crumbling roads with 330 stream crossings. Forests once choked with scrawny Douglas-fir host redwoods, grand fir, and many other native species. Now more salmon are spawning, and the team continues to monitor fish populations, tree growth, and tree spacing and planting options.”

And presently the Save the Redwoods League, in partnership with California State Parks and the National Park Service, is planning to thin out another 10,000 acres of forest. The logging initiative, which is part of a $5 million project called Redwoods Rising, will start at Del Norte Coast Redwoods State Park and Redwood National Park before moving to Jedediah Smith and Prairie Creek Redwoods State Parks. And this time, Douglas fir and tan oaks won’t be the only trees facing the saw: redwoods will be included as well.

That’s right — redwood logging is being used to restore redwoods.

Why? Because, according to Save the Redwoods League, “many of the spots under consideration were heavily logged decades ago before they were purchased and added to the parks….And cutting down the thinner trees — including those planted by loggers too densely as part of commercial reseeding operations in the 1960s — will restore more natural conditions, and reduce competition for sunlight and water, helping regular-sized redwoods grow faster into majestic old-growth giants…It’s about allowing the younger forests to grow more effectively,” said Sam Hodder, president of Save the Redwoods League. “Right now in some of these places all the trees are crowding each other out.”

Nevertheless, not all environmental groups are on board with this redwood logging initiative, but perhaps Redwoods Rising’s environmental impact statement, to be published later this year, will garner more support.

In any case, restoring these redwood forests is a vital undertaking, one that is about much more than the redwoods themselves. “Redwoods are helping us cope with climate change,” asserts California State Parks. "The size and longevity of redwoods help these forests store more climate-altering carbon dioxide than any other place on Earth. Even old redwoods continue to grow, each year adding more carbon-filled wood than smaller, younger trees do. After redwoods die, their rot-resistant wood keeps much of that carbon out of the atmosphere for centuries.”

Although the positive results of the redwood restoration efforts are already evident, California State Parks acknowledges that “decades or even centuries will pass before Mill Creek Watershed can charm visitors with as many gigantic old trees as it once had. Yet this watershed is still an impressive place. Flora and fauna are flourishing, and little by little, a once-mighty forest is coming back. Word is getting out: dedicated people can fix the mistakes of the past. Damaged land can heal in our care.”

Lathrop Leonard, a California State Parks Forest Ecologist who is in charge in the forest-thinning restoration program, surmises, “I’ll be dead and gone before this stand looks like it did historically. But if I can at least get…these forests on a trajectory or on a path that will help them achieve those conditions in the long term, then I’ll consider my work here successful.”