When lightning ignited fires in California’s Big Basin Redwoods State Park north of Santa Cruz in August 2020, the fire spread quickly. Redwoods naturally resist burning, but these fires reached the canopies of trees over 300 feet tall. “It was shocking,” says Drew Peltier, a tree ecophysiologist at Northern Arizona University. “It really seemed like most of the trees were going to die.”
Yet many of them lived, according to a report in Science magazine, and in a paper published in Nature Plants, Peltier and his colleagues explain why: The burned trees, despite losing their needles, mobilized their long-held energy reserves, the sugars that were produced from sunlight decades ago. The trees routed this energy into dormant buds under the bark.
“This is one of those papers that challenge our previous knowledge on tree growth,” says Adrian Rocha, an ecosystem ecologist at the University of Notre Dame. “It is amazing to learn that carbon taken up decades ago can be used to sustain its growth into the future.”
When the wildfires in 2020 burned through Big Basin Redwoods State Park, reported the San Francisco Chronicle, they left some of the oldest trees on the planet badly burned; researchers now have estimates of just how old the energy reserves of those redwoods are. Researchers studying a stand of severely burned old-growth redwoods found the buds were more than 1,000 years old.
Mild fires burn through coastal redwood forests about every decade, and the giant trees resist flames in part because the bark is up to a foot thick on the lower trunks, and it contains tannic acids that are fire-resistant. But in 2020 even the uppermost branches of many trees burned and their ability to photosynthesize went up in smoke along with their needles. Giant sequoias — which are different from the redwoods — can live for up to 3000 years, but in 2020 about 10 to 14 percent of the giant sequoias in the Sierra Nevada that were at least four feet in diameter were killed in the Castle Fire on the Sequoia National Forest.

A sprout emerges from thick redwood bark in Big Basin Redwoods State Park — 2021 photo by Drew Peltier, Northern Arizona University
Fire managers weren’t sure the trees on the Sequoia and in Big Basin would make it, but visiting the state park a few months after the fires, Peltier and his colleagues found fresh growth emerging from the trunks of blackened redwoods. They knew that shorter-lived trees can store sugars for several years. Because redwoods can live for more than 2000 years, the researchers wondered whether the trees were drawing on much older energy reserves to grow these new sprouts.

Melissa Enright with the USFS covered parts of 60 blackened tree trunks with black plastic to block out sunlight, ensuring that any new sprouts would grow with only stored energy, not new sugars produced from current photosynthesis. After 6 months, the team brought some sprouts back to the lab, and they radiocarbon-dated them to calculate the age of those sugars. At 21 years, they are the oldest energy reserves shown to be used by trees. But the mix of carbohydrates contained some carbon that was much older, and Peltier calculated that the redwoods’ carbohydrates were photosynthesized nearly 6 decades ago.
“They allow these trees to be really fire-resilient because they have this big pool of old reserves to draw on,” Peltier says. These redwoods have formed new sprouts, but Peltier and other forest researchers wonder how the trees will cope with far less energy from photosynthesis, considering that it will be many years before the trees can grow as many needles as they had before.
“It is likely that other long-lived trees also harbor carbon reserves that are much older than previously recognized,” said Peltier. The carbon stores observed in the trees, he told a Forbes reporter, date back as far as 1500 years, and they may provide hope for other ancient trees “destroyed” by fire.
Who would have thought that a fire dependent ecosystem would have done this?
Does anyone have any data on coast redwood re-sprouting from logged stumps and their mechanical resistance to structural failure (breaking off)?
GOOGLE SEARCH: re-sprouting redwood stumps after logging
Sprouting of old-growth redwood stumps…first year after …
US Forest Service (.gov)
https://www.fs.usda.gov › research › treesearch
Abstract. A survey of 104 old-growth stumps on the Redwood Experimental Forest, in northern California showed that (a) probability of a stump sprouting …
Missing: re- | Show results with: re-
Regeneration Dynamics of Coast Redwood, a Sprouting …
eScholarship
https://escholarship.org › content
PDF
by KL O’Hara · Cited by 35 — After disturbance or harvest, healthy redwood stumps sprout vigorously, often producing dozens of sprouts within two years of disturbance. …
19 pages
Dynamics of stump sprout regeneration after transformation …
ScienceDirect
https://www.sciencedirect.com › article › abs › pii
by R Muma · 2022 — 2018b). Increasingly complex aggregations of redwood stems arise following repeat harvesting and sprouting events that create sprout clumps …
Intensive Management of Stump0Sprout Reproduction In …
RNGR.net
https://rngr.net › tgl › at_download › file
PDF
Introduction. The habit of coast redwood (Sequoia sempervirens. (Lamb. ex D. Don) Endl.) to regenerate naturally from epicormic basal sprouts (stump …
Redwood Regeneration
KQED
https://www.kqed.org › quest › redwood-regeneration
Feb 28, 2011 — Stump sprouts are tiny growths from the base of existing trees. They can grow out of a healthy tree, or a tree that has been logged or damaged …
How Long It Takes for a Forest to Recover after Clear-cutting
Save the Redwoods League
https://www.savetheredwoods.org › grant › how-long-…
Dec 4, 2018 — After clear-cutting in coast redwood forests, many small sprouts spring up from the cut stumps. For the first couple of decades, these sprouts, …
Dynamics of coast redwood sprout clump development in …
Taylor & Francis Online
https://www.tandfonline.com › … › Volume 15, Issue 2
by KL O’Hara · 2010 · Cited by 53 — Coast redwood [Sequoia sempervirens (D. Don) Endl.] is relatively unique among coniferous species because of its ability to produce stump sprouts after cutting.
Dynamics of coast redwood sprout clump development in …
Springer Link
https://link.springer.com › Journal of Forest Research
by KL O’Hara · 2010 · Cited by 53 — Stump sprouts appear almost immediately after cutting and may number 100 or more per stump (Neal 1967). Over time sprout numbers decline through …
the adaptive strategy of coast redwood
ScholarWorks
https://scholarworks.calstate.edu › downloads
PDF
by DA Hughell · 1982 — Sprouting of old-growth redwood stumps – first year after logging. USDA. Forest Serv. Res. Note PSW-137. 8pp. Pelton, J. 1962. Factors influencing survival …
Redwoods Rising – Illustrations Through Time
National Park Service (.gov)
https://www.nps.gov › learn › nature › rrmontage
Apr 8, 2022 — … redwood habitats changed after being clear-cut logged in the 20th century. … Redwood saplings sprout from redwood stumps, fish are unable to …
Development of Redwood Regeneration after Conifer Partial …
Oxford Academic
https://academic.oup.com › forestscience › article
by JP Berrill · 2021 · Cited by 4 — Removing unwanted hardwoods by cutting or herbicide makes growing space available to residual trees and regeneration and can restore conifer …
What should I do about old invasive redwood roots after …
Stack Exchange
https://gardening.stackexchange.com › questions › wh…
Feb 11, 2016 — Tree roots stop growing immediately after the tree has been felled, but may take weeks to months (and longer) to die unless the stump has …
Redwood National and State Parks (NPS)
Facebook · Redwood National and State Parks (NPS)
840+ reactions · 2 years ago
section of logged redwood stump that was recently harvested by a burl … thousands of old-growth redwood stumps that are left over from …
Redwood propagation advice – Arborist Site
arboristsite.com
https://www.arboristsite.com › threads › redwood-pro…
Feb 7, 2008 — The redwoods do sprout well from stumps and roots after felling, but not as much from volunteer seeds for some reason. I understand from some of …
Understory stump sprout development under variable …
ResearchGate
https://www.researchgate.net › publication › 223774893…
… Redwoods can produce in excess of 100 sprouts per clump [33] that grow exceptionally fast in full sunlight, but also self-thin over time. O’Hara et al. [34] …
Natural regeneration in old-growth redwood cuttings
Eastern Forest Environmental Threat Assessment Center
https://redwood.forestthreats.org › REForest › Assets › B…
By August redwood stumps had started to sprout–even before all logs had been … ances both classes of trees are well represented and growing vigorously.