In May, a human-caused wildfire raised serious ecological concerns after it burned over one-third of Santa Rosa Island — an offshore wildlife oasis in Southern California’s Channel Islands National Park.
Concerns have turned into somber truths on the windswept island, which emerges from the ocean about 26 miles off the mainland, and hosts flora and fauna found nowhere else on Earth.
The wildfire, the largest in the park’s history, devastated a critically endangered grove of Santa Rosa Island Torrey pine trees — some of the rarest pines in the world — according to recent federal damage assessments on the island.
🌲🦊Learn about other wildlife impacted by the fire in the CNN Weather app. 🦨🐦
Some trees died immediately, the assessments found, but the long-term outlook is even more bleak: 60% to 80% of the trees are predicted to die based on the extent of the damage, Ana Cholo, a National Park Service spokesperson, told CNN. Only 2% of the grove was unburned, she added.
“Because Torrey pines are not well adapted to fire, even low-severity burns may result in delayed mortality,” Cholo said. “A detailed assessment is underway, and the full extent of impacts may not be known for at least a year.”
The loss could have trickle-down effects on the island. These scaly, contorted pines, positioned on sandstone bluffs above the sea, catch fog with their needles, funneling water to their roots as well as neighboring plants and animals.
“Plants like this affect local water availability and can make a huge difference in terms of how much water is captured by life on the ground,” Heather Schneider, the director of conservation and research at Santa Barbara Botanic Garden, told CNN.
A fiery loss and a fledgling grove
Even before the wildfire, the Santa Rosa Island Torrey pine was “very vulnerable to extinction,” due to its limited range and gene pool, the National Park Service said.
Such small, isolated populations of rare plants are “extremely vulnerable” to destructive events like fire, Dustin Wolkis, the director of science and conservation at the nonprofit Center for Plant Conservation, told CNN.
“When you lose even just a little bit of genetic diversity, that can be catastrophic for the population,” he said.
Genetic diversity makes it more likely that some individuals will have traits required to survive environmental change, such as new diseases.
“Once that genetic diversity is lost, you cannot get that back,” he said. “All you can do is maintain what you have.”
Genetics aside, the loss of a large portion of an already small population means there are less individuals to withstand the next challenge.
“As the population decreases, resiliency also decreases,” Wolkis said.
The damaged island grove may be able to get a little help from the mainland, according to Schneider.
In what she called “an eerie twist of fate,” the botanic garden had been collecting seeds from the island pines for a few years prior to the burn. The organization was able to cultivate the seeds and recently established a conservation grove of them, she said.
“So that’s a glimmer of hope — that we have a subsample of the island trees safely at our garden,” Schneider said, adding that they have about 40 more at their nursery.
Those plants could be deployed to help the grove recover, though she emphasized it will take time to determine whether intervention will be necessary.
The botanic garden, the Center for Plant Conservation and other organizations also have additional Santa Rosa Island Torrey pine seeds squirreled away — a practice Wolkis says is imperative for protecting rare plant populations.
But the remaining island pines may have a seed bank of their own.
While the trees drop most of their seeds when they mature, they also hold onto some for much longer, sometimes over a decade, according to Schneider. If some of those seeds survived in the treetops, even dead trees might be able to help rebuild their arboreal community on the Santa Rosa Island bluffs.
Whether planted by hopeful human hands or germinated from a scorched pine cone, new island Torrey pines will also be challenged to survive in an ecosystem shaped by global climate change.
Many plants need a relatively narrow range of environmental conditions to complete the various stages of their lifecycle, and conditions are changing on Santa Rosa, according to Schneider. Temperatures are increasing and the rainy season is starting later, for instance.
“It’s a hard time to be a pine tree on Earth as the climate shifts,” Schneider said. “A question that I have is not only, ‘Do we have viable seeds still in those cones that could potentially drop and regenerate?’ but then also, ‘Are they going to experience the climatic conditions that allow them to not only germinate, but grow to maturity and start reproducing?’”
Before the burn, the grove was flush with young trees, which tells Schneider conditions the last few years have been adequate for seeds to sprout and grow. But young trees have to survive over a decade until they can reproduce and sustain the grove, and Earth’s climate continues to change.
If climate change makes the island hotter and drier and more fire-prone, that could lower the chances of the pines recovering naturally, she said.
“Time will tell, but for now, I feel hopeful about the prospect of regeneration from seed.”