As the great giant sequoias show signs of stress from California’s drought, these forest scientists scale the magnificent titan trees to give them a check-up.
Long before humans started making their mark on the planet, giant sequoias had been doing their giant tree things – for millions of years, in fact. Carving out their space in a small pocket on the western slopes of California’s Sierra Nevada mountain range, giant sequoias (Sequoiadendron giganteum) are the biggest trees on Earth and some of the longest-living organisms as well. The oldest one on record reached a ripe old age of 3,200 years; John Muir reportedly found a stump with 4,000 tree rings, indicating one per year. In their youth they may suffer from the hand of nature, but after a few centuries they become nearly indestructible.
But now California’s gentle giants are facing the doom cast by another year of drought, along with the state’s other trees. According to the Carnegie Airborne Observatory about 70 million trees have died across the state since 2011, with another 100 million potentially soon to follow.“California’s forests generate fundamental ecosystem services by creating healthy watersheds, providing wildlife habitat, and sequestering atmospheric carbon, and they’re dying at unprecedented rates,” writes Thayer Walker for the California Academy of Science's bioGraphic. And now, even the stalwart sequoias are showing signs of strain – which is where forest ecologists Wendy Baxter and Anthony Ambrose from UC Berkeley’s Dawson Research Lab enter the picture. The pair are part of the Leaf to Landscape program which is a collaboration with the United States Geological Survey, the National Park Service, and the Carnegie Airborne Observatory. Their aim is to study and manage the health of these arboreal treasures.
According to those who know trees, it’s extremely rare for a giant sequoia to die standing upright. “You don’t get to be 2,000 years old without surviving a few dry spells,” says Ambrose. Which is why United States Geological Survey forest ecologist Nate Stephenson was so concerned when, in 2014, he went for a walk in the Giant Forest and saw something unexpected, explains Walker. In three decades of studying trees Stephenson had only seen two die “on their feet.” After five years of this punishing drought, he says there are now dozens.
So it’s up into the trees for Baxter and Ambrose, who are tasked with the (glorious) job of climbing these beauties to collect samples. Which is no easy gig given the insane magnitude of these trees. As Walker writes:
In terms of sheer volume of biomass, no living organism ever to walk, swim, fly, or stand on this planet comes close. They are of such stature that people struggle to describe them and so compare them to other very big things: blue whales, 747s, dinosaurs, the Statue of Liberty, elephant herds, space shuttles. Giant sequoias make mice of them all.
In the following videos we join Ambrose and Baxter into the forest and up the trees. It's nothing short of breathtaking. Says Ambrose, “From an aesthetic perspective to a biological one, these trees are some of the most spectacular organisms on the planet. They are the pinnacle of what a plant can become. They force you to think about life and your own place in it.”
In the video below, Baxter explains the magic of the trees as the camera follows her to the top.
Here Ambrose talks about the trees, the stress they are facing, and more about the research that these tree saviors are conducting.
To read all of Walker's wonderful story on the giant sequoias, see Last Tree Standing at bioGraphic.com.