Ancient Forest Society

10/14/2026

Pershing Tree inspection - October 14, 2026

Earlier this month we conducted a bark beetle inspection of the Pershing Tree, a giant sequoia growing in the Placer County Big Trees Grove on the Tahoe National Forest. This grove is the northern most giant sequoia grove and is geographically isolated from the rest of the sequoia range. Over the past three years our team has looked for native bark beetle activity in healthy and dying giant sequoias throughout the range. This includes famous trees like the General Sherman and Grizzly Giant! We’ve inspected more than 360 individual trees in 25 groves. We’ve found bark beetle activity in the canopy of every grove we’ve looked in and in most of the trees we’ve climbed. The vast majority of trees we’ve climbed are vibrant and successfully defending themselves from beetle attack, a testament to the resilience of these amazing organisms. We have a lot more information to share about this important ongoing work, so stay tuned! If you want to support this critical giant sequoia monitoring project, please go to our website to learn more.

Thanks to for supporting this work!

07/31/2026

This short video shows some of the highlights from our Grizzly Giant health assessment. The assessment took place in Yosemite National Park’s (YNP) Mariposa Grove in collaboration with , , and the Southern Sierra Miwuk Nation. In fact, YNPs very own Forest Ecologist, Garrett Dickman, joined us in the tree to help with the inspection. He’s shown admiring an epiphytic sugar pine partway through the video.

Over the course of two days we evaluated the mammoth tree’s health by looking at its water status, reproductive health, fire damage, and bark beetle activity. While one would assume that the Grizzly Giant has always been a vibrant, healthy tree, there was a photo taken in 1861 by Carleton Watkin that shows the giant with a sparse crown. Since that time the tree has regrown its foliage and is thriving and healthy once more, but that historic photo reminds us not to take these living cathedrals for granted. This is why we conducted the health assessment.

One of the most important tools giant sequoia land managers have to support the long-term health and resilience of giant sequoias is fire. Prior to the arrival of European settlers, Indigenous peoples used cultural burning as an ecosystem management tool. In the mid 1800’s, they began to be displaced from their traditional lands, leaving these areas to become slowly degraded. Fire suppression became the norm and the health of the giant sequoia groves began to decline.

Thankfully, we have come full circle and now appreciate the ancient wisdom of Indigenous ways. Checking on the health of one of our elders was just one important step in continuing to protect the giant sequoias. YNP, Yosemite Conservancy and the Southern Sierra Miwuk Nation are actively partnering on cultural burns and the Park has had an active prescribed fire program since the 1970’s.

Being among the massive branches of the Grizzly Giant was awe inspiring. We hope this video brings you there with us, even if briefly. If you want to learn more, visit our website where you can find a report and a longer video about the health inspection.

08/26/2024

Giant sequoias are some of the most resilient trees on the planet. They grow in the same place for thousands of years and weather fierce winter storms, lightning, fire, floods and droughts. Even long after they die their wood can persist for centuries as standing skeletons or logs on the forest floor.

This year, Ancient Forest Society is finishing up one project and starting several others aiming to uncover some of the giant sequoias’ secrets of resiliency. Accomplishing all of these goals has required our team and volunteers to internalize the lessons of the sequoias. We’ve had to dig deep and climb high to unlock the mysteries of the sequoias. Here are a few moments from our time among these amazing trees. Music: Night Light by Filo.

This work wouldn’t be possible without dedicated volunteers and funding from a number of organizations including: , , , , , , Jeffrey Seller Family Foundation, Wildlife Conservation Board, The Petzl Foundation

06/23/2024

05/26/2024

https://www.latimes.com/california/story/2024-05-25/column-gen-sherman-sequoia-ambassador-from-another-time-gets-a-checkup-amid-health-scare

General Sherman appears to be holding up well (not bad for a 2,200-year-old), but because of pests and climate change, the largest tree in the world needs a checkup

05/25/2024

We just climbed the largest tree on the planet! The General Sherman giant sequoia, located in Sequoia National Park, has never been climbed before. Our executive director, Anthony Ambrose, was the first person to climb into this iconic tree. He led our research team in climbing the General Sherman to inspect it for any evidence of bark beetle activity. Concurrently, a team of researchers from the National Park Service used drones and satellite imagery to see if they could detect the beetle activity we were seeing. Climbing trees is very labor intensive and having an alternative way to monitor bark beetles would be very useful to land managers. While both teams found some beetle activity, it was mainly attempted entry holes. The inspection determined that the General Sherman is a very healthy tree, capable of protecting itself from bark beetles.

This event was a way to raise awareness of this issue and showcase the amazing collaborative work being done by the Giant Sequoia Lands Coalition, a group of 11 land management stewards, supported by other agencies and non-government affiliate organizations, including Ancient Forest Society. The mission of the Coalition is to accelerate the protection of giant sequoias and their ecosystems, in a new era of emerging threats associated with climate change and human interference of natural wildfire processes on the landscape.

Ancient Forest Society was invited to inspect the General Sherman because we have been examining bark beetles in giant sequoias since 2017, when we first discovered evidence of bark beetle attack in the crown of a living tree. A native beetle appears to have played a role in the recent death of dozens of mature sequoia trees weakened by fire and drought. There is therefore an urgent need to increase our knowledge of the ecological and physiological mechanisms underpinning sequoia tree interactions with bark beetles to develop effective conservation strategies for sequoia groves. To meet this critical need, we launched a new bark beetle study, in collaboration with scientists from Colorado State University and with funding provided by the CAL FIRE Forest Health Research Program. This two-year study will delve deeper into this issue and aims to provide land managers with information to help address this emerging threat.

Huge thanks to the AFS crew, NPS staff, and other Coalition partners!

If you would like to support this critical work, please go to our website to make a tax deductible donation!

05/23/2024

https://apnews.com/article/sequoia-trees-climate-beetles-california-sierra-nevada-94dd718bda612a54f2fff627ebccfe52

Researchers climbed the world’s largest tree to inspect for bark beetles and descended the giant sequoia with good news this week.

04/11/2024

Ancient Forest Society seeks a Program Associate to join our South Lake Tahoe-based team working to study and protect old trees and forests. As a core member of our growing organization, the Program Associate will contribute to canopy-based scientific research and tree seed collection projects, guided tree climbing events, visual and other media, outreach and education campaigns, canopy exploration, and other programs aimed at conserving critical forest ecosystems.

For the full job description and information about how to apply please go to our website (ancientforestsociety.org/careers)