Woody Biomass 101: From Forest Waste to Forest Opportunity

Every time land stewards thin a forest to reduce wildfire risk and open up the forest floor for wildflowers and other plants, they face a surprisingly big challenge: What should we do with all the leftover wood?

An array of expert land stewards care for the forest in the Santa Cruz Mountains:

What is Woody Biomass?

Across the Santa Cruz Mountains and beyond, forest restoration projects can leave behind large amounts of leftover vegetation. Known as woody biomass, this build-up includes the trunks, branches, wood chips, and sawdust that remain after forest management work. While generating these materials are a necessary part of restoring forest health, managing them isn’t always simple. Transporting, processing, and finding productive uses for excess wood can be one of the trickiest puzzles facing land stewards today.

At POST, we’re exploring how this challenge could become an opportunity that supports healthier forests, safer communities, and more resilient ecosystems.

How Does Forest Restoration Support Healthy Forests?

POST’s working region includes redwood forests, oak woodlands, and mixed evergreen forests across foothills, valleys, and canyons. Acquiring and protecting landscapes like these is only the beginning. Forests are dynamic living systems that require ongoing care.

Alongside our partners, we employ forest management techniques to reduce wildfire risk and improve forest health. These practices help create more resilient landscapes by removing excess vegetation and giving larger, healthier trees more room to grow.

For thousands of years, Native people in California have stewarded these lands using fire to maintain healthy ecosystems and support the growth of important plant species. When colonizers disrupted and prohibited these practices, forests began to change. The began growing denser and accumulating more vegetation that can fuel large, hot wildfires. Today, forest restoration efforts are helping reintroduce some of these time-tested stewardship practices, recognizing the vital role Indigenous communities have long played in caring for the land.

Why Are Today’s Forests More Fire-Prone?

Many forests in the Santa Cruz Mountains look very different than they did a few centuries ago. A legacy of clear-cut logging and more than a century of fire suppression reshaped the forests we see today. In many places, dense stands of smaller trees have replaced the more open forest structure that historically characterized these landscapes.

This overcrowding, dense spacing, and overloaded structure,  can increase wildfire risk. When forests have too much vegetation packed closely together, there is more fuel to burn, allowing the fire to move more quickly and burn more intensely.  Many of our trees have adapted to tolerate (or even thrive in) low intensity fires. In contrast, these larger scale, hotter fires can lead to a lot of tree mortality.

The 2020 CZU Lightning Complex Fire showed how devastating and even deadly these conditions can be. The fire burned more than 86,000 acres in the Santa Cruz Mountains, destroying more than 1,000 homes and structures, and displacing people and wildlife. It also underscored why proactive forest management is so important. Taking action before the next major wildfire can help create safer, more resilient landscapes.

Why Is Woody Biomass So Hard to Manage in the Santa Cruz Mountains?

At first glance, the solution might seem simple: remove the extra material and put it to use. In practice, it’s much more complex.

Managing woody biomass in the Santa Cruz Mountains is challenging because:

• Many forested areas are divided among smaller properties with different owners, goals, and resources.
• Steep slopes and limited road access make it difficult to move material out of the forest.
• Hauling wood can be expensive, especially when destinations are far away.
• There are too few nearby facilities for sorting, storing, and processing biomass.
• Our region only produces redwood lumber commercially, with no mills available for other species.
• Many of the trees were badly damaged by the wildfire and are no longer strong enough to use as building materials.

These challenges mean there is no single answer. Instead, our region needs flexible, practical approaches that work across different landscapes, ownership patterns, and tree types. 

For the reasons above, redwood lumber is the only merchantable timber. This means that the excess or dead oaks, madrones, Monterey pines, Doug fir, eucalyptus, and all other tree species have no market. In other areas of California and the West, specialty sawmills can process these trees and put them to use. Meanwhile, in our area, they are simply burned or chipped as “waste” in forest health projects. 

What Is POST Doing About Woody Biomass?

POST and our partners already use several approaches to manage excess vegetation after forest restoration work. In some places, crews burn piles of vegetation. In others, they use air curtain burners or carbonizers, which reduce some smoke pollutants compared to traditional pile burning. Wood chips may be scattered on-site, and some material can be transported for compost or firewood production.

These methods are useful, but they don’t solve the entire problem. Cost and efficiency remain significant hurdles.

Here’s what an air curtain burner looks like in action:

That’s why, as a member of the Santa Cruz Mountains Stewardship Network, POST is helping explore better solutions. The network recently completed the first phase of a regional effort to better understand woody biomass challenges and identify practical opportunities. This work brought together experts in scientific research, forestry, and geospatial analysis to explore options that could work for our region.

The guiding question is simple but important: How can we make it easier for landowners and land managers to put excess wood to good use?

How Can Woody Biomass Become Useful Products?

One promising path is finding better ways to transform woody biomass into products that benefit both people and the environment.

Some material could become compost or firewood. Alternatively, it could be turned into biochar, a charcoal-like material that can improve soil health while storing carbon for years or even decades. In some cases, wood could become building materials, furniture, or other locally made products.  

Using the wood for furniture or lumber instead of burning it has another important benefit: it keeps carbon stored in the wood—your dining table, for instance—rather than releasing it into the atmosphere. As long as those products remain in use, that carbon stays locked away, making the most of a valuable natural resource.

We’re also exploring more creative possibilities. For example, Douglas fir from our region may not be available in large enough quantities to compete economically with redwood. But could it be used for smaller artisanal projects, where natural features like bug holes add character?

And what about smaller trees such as tanoak or madrone? Could a local processing facility turn some of that material into engineered wood products for construction?

These are the kinds of questions POST and our partners are asking. Many emerging technologies show promise, and we’re excited to continue exploring which solutions make the most sense for our forests, communities and ecosystems.

A Regional Challenge Requires Regional Collaboration

Woody biomass is not just a forestry issue. It touches wildfire resilience, climate resilience, local economies, habitat health, and community safety.  Tackling this issue on a regional scale makes it easier for other landowners to implement fuel reduction work too, but potentially off-setting costs for future forestry work.

That’s why collaboration is so important. Input from public agencies, private landowners, timber operators, tribal partners, conservation organizations, and others helps ground this work in the realities of the region. Each partner brings a different perspective on what is possible, practical and beneficial.

Creating Value, Not Waste

The goal is not simply to get rid of excess wood. It’s to build a system where forest restoration creates value instead of waste. In a community that prizes local food and art, why not bolster another local market — locally sourced, sustainably harvested wood products? 

Foresters think about the “highest and best use” of any wood being removed from a forest — meaning we should honor the tree’s lifework (reaching for the sun, photosynthesizing energy, finding nutrients with its roots, producing oxygen for us to breathe, and growing larger to support the whole ecosystem) by not leaving the cut up, excess wood on the forest floor.  Instead, we strive to evaluate the type of wood material we’re producing and make the most of this important resource, perhaps converting the larger pieces into something useful.  

Some stately trees might make lovely kitchen tables, others might be better suited for building a deck or a raised bed.  The unsound trees, perhaps those most badly burned by the fire, could be converted into bio-char for our agricultural industry or burned to produce electricity.  And a lot of smaller woody material will be left in place to restore the soil’s nutrients and create habitat for our forest floor dwellers, like frogs and mushrooms.

Building a More Resilient Future for the Santa Cruz Mountains

For hundreds of thousands of years, people have used wood to build their homes.  Nowadays, most of the materials we use for building come from faraway places. Meanwhile, local land managers are having to leave cut trees on their properties to either burn in the next wildfire or rot in place. As our forest health strategies are evolving, we have an opportunity to decide if our community is ready to utilize locally derived, sustainably harvested materials that make our forests healthier.   In fact, every branch, log, and wood chip represents an opportunity to reduce wildfire risk, support local solutions, and help build healthier forests for future generations.

By finding better uses for woody biomass, we can support healthier ecosystems, strengthen regional resilience and create new opportunities that benefit both people and nature.

At POST, we’re inspired by the collaborative spirit behind this work. Together with our partners, we’re helping shape a future where the forests of the Santa Cruz Mountains are healthier, more resilient, and protected for generations to come.