What will tomorrow’s redwood forest look like?

MENDOCINO CO., 7/19/26 — After several years of planning, public outreach and environmental review, Cal Fire has begun the next phase of the Coastal Adaptive Management Experiment, commonly referred to as AMEX, at Mendocino County’s Jackson Demonstration State Forest. The long-term research study will evaluate several forest management strategies designed to improve the resilience of California’s coastal redwood forests to climate impacts.

AMEX is part of a larger network of replicated experiments across the Sierra Nevada and coastal redwood forests, comparing treatments that mimic historic fire regimes, promote species diversity and reduce carbon loss. The research, funded through a California Forest Health Grant matched by the Demonstration State Forest Program, is designed to generate and track long-term changes in forest composition, structure and function. The treatments represent a suite of plausible management approaches that land managers may use to address both ongoing and emerging stresses on forest ecosystems.

The Mendocino Voice recently toured one of the research sites with Cal Fire staff and researchers from the University of Nevada, Reno to see how those strategies are tested in the field.

Kevin Conway, Cal Fire’s staff chief for resource protection and improvement for California’s demonstration state forests, said the Coastal Adaptive Management Experiment is the first project designed to support both Jackson Demonstration State Forest’s Forest Management Plan and its New Vision initiative, which emphasizes tribal collaboration, public engagement, ecological restoration and climate resilience. 

Planning for the project began in 2022 and included presentations at several public meetings of the Jackson Advisory Group. Conway said local tribes were invited to participate from the outset, received access to the project area during development, and helped shape both the research design and the project’s footprint.

Camp 20, a forest access and day-use area on Highway 20 within Jackson Demonstration State Forest, served as the meeting point for the field tour. The site provided both an entry point into the redwood forest and a baseline area where no treatment will be applied and thus could be used for comparison.  

Rather than relying on assumptions, Conway explained that each treatment area is divided into multiple study plots designed to gather data and determine which management practices best support healthy redwood forests.

Before heading into the forest to meet with researchers at one of the experimental sites, Conway, Justin Britton, Cal Fire’s statewide Demonstration State Forest Program manager, and Cal Fire forester Jeremiah Steuterman provided a brief introduction to the field tour.

Conway said, “The experimental treatment plot areas  will provide scientific evidence to help guide future forest management at Jackson Demonstration State Forest and across the redwood range. When we think about safeguarding the forest against disturbances, the biggest driver we think about is wildfire. But here on the coast, and in forests throughout California, we also think about drought, high heat, changing fog patterns, and insects and diseases that might impact the forest.” 

He explained that the project tests three different forest management approaches: resistance, resilience and transition. He said that real-world forest conditions would show how “each strategy influences the forest’s ability to respond to climate change and other disturbances….  Can we protect what we have from climate change, or do we have to help the forest adapt to climate change?”

Steuterman added that the sites will be monitored for at least 20 years. “The resistance treatment site that we are going to is focused on keeping large trees and getting rid of ladder fuels — those types of treatments that we think of as keeping a forest safe from wildfire. If a fire burns through, we would expect very little damage to the trees that are there.”

Out in the field

After following old dirt logging roads that wind along the ridgelines and climbing about 1,000 feet into the forest, the group met with University of Nevada, Reno researchers Conor Phelan, senior analyst, and Bryant Nagelson, project analyst, part of the AMEX team.

Phelan explained that each plot is about one-tenth of an acre and is circular. “Within that circle, we tag what we call `mature trees,’ which is a term we use for any tree measuring at least 4.5 inches in diameter at breast height — that is, 4.5 feet above the ground. By doing this, we can determine how many trees are present in each one-tenth-acre plot and track how the forest changes over time. We have more than 300 of these locations where we collect this information and characterize the forest.”

Nagelson  added, “All four treatment areas roughly cover about 500 acres.”

Phelan explained that landowners in the coastal redwood ecosystem commented that employing this particular treatment—removing ladder fuels and keeping mature trees might not be the most effective approach in the bottom of a watershed. The landowners suggested that kind of strategy might work best along ridgelines or in areas where managers could safely access the forest to remove fuels and conduct prescribed burns.

“For example,” Phelan said, “when we were in Santa Cruz, we were standing on a ridgeline discussing where a land manager might place a fuel treatment or promote the growth of larger trees. The idea was that if a fire moved through the area, a treatment along that ridge could provide an opportunity to safely introduce fire and help protect nearby communities. We listened to their concerns and incorporated them into how we designed the treatment units. The idea forces fire to stay on the ground.”

In a follow-up interview, the Mendocino Voice spoke with Dr. Sarah Bisbing, an associate professor of forest ecology at the University of Nevada, Reno. She is the lead scientific investigator for the Coastal Adaptive Management Experiment and is leading the research in partnership with Cal Fire.

Bisbing and her research team designed the study and will monitor how the different forest management strategies affect forest health. Bisbing’s collaboration with Cal Fire began with a project studying Monterey pine forests in Cambria. That partnership led to an invitation to conduct research at Mountain Home Demonstration State Forest, home to old-growth giant sequoias, where one of the first adaptive management experiments was established.

She collaborated with Cal Fire on research sites in coastal forests, including Big Sur and other redwood ecosystems. That eventually led to Jackson Demonstration State Forest, which became the foundation for the Coastal Adaptive Management Experiment.

Deep dive: Three forest management strategies

Bisbing explained that the AMEX project is based on three well-established ecological concepts — resistance, resilience and transition — that have been studied for decades.

The framework for applying these three approaches traces back to a 2007 paper by California forest scientist Connie Millar, who described how forests could be managed under uncertain future conditions. Millar and her colleagues argued that managers needed a range of strategies to address forests facing uncertain climate futures. Rather than relying on a single approach, Millar outlined three adaptation pathways to prepare forests for ecological change.

“The concept of resistance is helping individual trees resist mortality when a disturbance moves through,” Bisbing said. “That could be wildfire, drought, bark beetles or disease. We’re keeping the largest trees, removing ladder fuels and promoting growth in the trees that remain. Bisbing said the resistance treatment preserves mature forests by protecting large trees and reducing wildfire fuels, while the resilience treatment aims to help forests better withstand and recover from disturbance.

Resilience depends upon varied forest structure. “Resilience focuses on helping the forest recover after disturbance rather than preventing damage altogether,” Bisbing said. “Treatments maintain a mix of tree species, ages and sizes, while creating openings of different sizes to encourage regeneration and study how forests respond after fire or other disturbances. The concept is that the forest will bounce back,” she said.

Transition recognizes that some forests may change permanently as climate conditions shift. “Foresters have to figure out what to do with the forest they’re left with,” Bisbing said. Bisbing explained that the transition approach recognizes that climate change may push some forests beyond historical conditions.

When severe disturbances such as drought and high-intensity wildfire cause widespread tree mortality, managers must decide how to guide the forest toward a new future based on the conditions that remain. She cited the Dolan Fire as an example of a landscape where foresters had to adapt management decisions after an unprecedented level of forest damage. The Dolan Fire was a significant wildfire that occurred on September 8, 2020 in the Monterey Ranger District of the Los Padres National Forest, California 

In the aftermath, researchers are examining which tree species are most likely to survive under hotter, drier conditions so future reforestation efforts can favor species better adapted to those environments.

Why the treatments are located where they are

Said Bisbing, “We did not randomly assign treatment locations or plots at Jackson. We worked with local land managers and community members in test sites to place treatments where they would have the greatest practical value.”

Resistance treatments were generally located along ridgelines, while resilience treatments were placed on steeper slopes where maintaining diverse forest structure was the priority. Transition treatments were established in areas suitable for testing planted seedlings under different conditions.

“We’re testing those three treatments side-by-side with an untreated control,” Bisbing said. “As disturbances move through, we’re looking at what the outcomes will be, how forests will change, and whether we’ll meet our objectives or maintain those ecosystem services going forward.”

A statewide and national effort

Bisbing said the California research complements a broader national effort inspired by Millar’s 2007 paper that  reintroduced the resistance, resilience and transition framework. While the national network compares different forest types across North America, California’s AMEX replicates the similar treatments across multiple sites within the same forest type, allowing researchers to draw stronger conclusions about which management approaches work best under similar ecological conditions.

“Our goal is to understand which management strategies help forests continue providing the benefits people value as the climate changes,” Bisbing said.

Jackson Demonstration State Forest encompasses 48,652 acres, making it by far the largest of California’s 50 demonstration state forests. Established in 1947 after the state purchased the property from Caspar Lumber Co., the forest was created to demonstrate sustainable forestry while supporting research, education and public recreation.

Management of Jackson Demonstration State Forest has been the subject of ongoing public debate over timber harvesting, environmental protection and tribal stewardship. Environmental organizations and some local residents have called for greater protection of older redwood stands, wildlife habitat, carbon storage and watersheds. Tribal representatives have also sought a larger role in managing lands they consider culturally significant.

Public field tour

On July 21, Cal Fire  will host a public tour and information meeting from 4 to 6 p.m. at Camp 20, located at mile marker 17 on Highway 20. The public is encouraged to RSVP by calling (707) 964-5674 or emailing JDSF@fire.ca.gov, although RSVPs are not required.

The meeting will provide an opportunity for community members to learn more about AMEX, ask questions and hear directly from Cal Fire staff about planned forest treatments, what visitors may see during operations and how the project will be monitored over time. Participants should be prepared for field conditions, including uneven ground and variable weather. Sturdy footwear, water and weather-appropriate clothing are recommended.