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Forest Stewardship

Forging New Paths in
Research and Conservation

The landscapes we own and manage are rich in biodiversity, providing a home to many species of wildlife, aquatic life and plants.

As stewards of working forests, we take an active role in research and conservation planning to keep all aspects of our natural ecosystems intact. In 1992, we became the first privately owned company to receive the U.S. Fish and Wildlife Service’s approval for a Habitat Conservation Plan (HCP) for the northern spotted owl. Today, over 1.5 million acres of our timberlands are managed under conservation plans and permits that address the needs of more than 60 protected or sensitive species.

These conservation management plans and permits incorporate the best of science and resource management. They also provide many indirect benefits to other wildlife, plant life and water resources. By working closely with state and federal officials, we support biodiversity across our landscapes and ensure our continued compliance with the U.S. Endangered Species Act and other protections and regulations.

While our original research focused on the northern spotted owl, our investigations and conservation practices have since blossomed to include a host of wildlife, fish species and plant species.

Wildlife Conservation

The health of a working forest extends far beyond its trees—including a wide variety of wildlife species. Our core value of stewardship drives us to treat these animals with respect as we focus on programs to study and protect threatened and endangered species. Learn more about our wildlife research and conservation work:

When the northern spotted owl was listed as a threatened species in 1990, it brought into sharp focus the potential conflict between timber operations and wildlife protection in the Northwest. The species was originally believed to survive only in old-growth preserves where there was little or no forest management activity. However, research conducted on Green Diamond’s timberlands along California’s North Coast indicated that this theory was not true.

Photo by Drake Fehring

That year, we hired a wildlife biologist to study the impact of timber operations on wildlife in our forests, with a focus on the northern spotted owl. This groundbreaking scientific research and monitoring program led us to develop an effective means to sustain populations of spotted owls during our timber operations. As a result, our timberlands have been identified as one of the most populous spotted owl areas in the Northwest. Since launching our research more than three decades ago, we have continued to monitor the population and during this period have identified over 1,700 adult and juvenile spotted owls on our property alone.

As a result of this research, our California timberlands were the first privately owned timberlands to be awarded a U.S. Fish and Wildlife Service HCP for the northern spotted owl. Today, we continue to evaluate the effectiveness of this HCP, conducting yearly reviews of long-term population trends, including the species’ survival and reproductive rates. The U.S. Fish and Wildlife Service also conducts annual reviews, and we continue to collaborate with officials to protect this and other listed species.

The Del Norte salamander is a terrestrial salamander that is closely associated with talus (rocky slopes), and in some cases, has shown sensitivity to timber harvesting practices. Our studies indicate, however, that the species is not as sensitive to timber harvesting activities in our coastal California region, apparently due to the cool, moist climate that supports its habitat.

Through our research on spotted owls, an important question arose: What is it that attracts them to our forests? The answer, we found, is the dusky-footed woodrat, which many owls rely on for prey.

Photo by Suzanne Guldimann

While most spotted owls in the Northwest feed on flying squirrels that live in mature forests, the owls along California’s North Coast tend to prey on woodrats. A study on the abundance of woodrats in Green Diamond’s redwood forests indicated that woodrats are most abundant in young—meaning 10- to 20-year-old—forest stands. Preliminary data from an additional, ongoing study through Humboldt State University shows a similar abundance of woodrats in Douglas fir forests. These results helped us understand why spotted owls in this region do well in areas that include both young and mature trees.

Wildlife biologists and other Green Diamond experts in California continue to study woodrats to better understand how different methods of harvesting affect their population. While these studies are not yet published, they indicate that we can support woodrat populations by enabling sunlight to reach the forest floor, therefore enabling the shrubs that woodrats feed on to grow. Given the importance of woodrats as the prey of spotted owls, these results also suggest that spotted owl populations in this area are best supported in forests under even-age management.

So rare is the Humboldt marten—a member of the weasel family—that it was thought to be extinct in California until a small population was rediscovered in 1996. More than two decades later, in 2020, the U.S. Fish and Wildlife Service finalized the animal’s status as a threatened species. However, even before that designation, Green Diamond entered into a voluntary safe harbor agreement with the California Department of Fish and Wildlife to help assist marten recovery and create the potential for it to expand its range across coastal areas of our California operations.

Photo by Matt Delheimer

Under the agreement, we committed to creating a 2,100-acre no-harvest reserve area for the marten, as well as a 127,000-acre special management area for its dispersal and monitoring. We also provide funding and in-kind resources to support programming and studies dedicated to supporting and understanding the marten’s dispersal across both managed and public lands. The goal of the 40-year agreement is to conserve, restore and increase marten habitats, and therefore expand the species’ population. The agreement is also structured to create opportunities for neighboring landowners to enroll their own land in the agreement and contribute to our conservation efforts.

While Green Diamond's original HCP was primarily designed to benefit spotted owls, it has also provided indirect benefits for other species associated with mature forest conditions. One example is the Pacific fisher, a medium-sized carnivore and member of the weasel family, which, along with the spotted owl and other species, is mainly associated with old-growth forests.

Through a Humboldt State University study, funded by Green Diamond to determine the Pacific fisher’s occurrence on our timberlands, we found that its habitat was similar to that of the spotted owl. This led to a telemetry study of fishers by Green Diamond biologists to follow the species’ movements and determine the types of trees that were critical to its habitat. Our research demonstrated that most conservation measures developed to protect spotted owls also benefited Pacific fishers. Since gaining these insights, we have continued to join Humboldt State University to study fisher populations in our forests and have modified conservation measures originally developed for spotted owls to provide maximum benefits to both species.

In 2019, we included fisher in our new Forest HCP approved by the U.S. Fish and Wildlife Service for conservation of the species in California, and we signed a CCAA with the U.S. Fish and Wildlife Service to protect the fisher across nearly 500,000 acres of our working forest land in Southern Oregon—the first such agreement completed in Oregon. Under the 29-year agreement, we continue to support the fisher and other neighboring species by creating buffers around its den sites, thinning the forest to restore dense stands, extending the growth period of trees to increase the carbon-sequestration capacity and timber volume on our lands and managing the area in accordance with SFI standards.

Red tree voles are small, nocturnal and arboreal (tree-dwelling) mammals. They are unique in that they appear to feed only on conifer needles, which also makes them exceedingly difficult to observe or trap.

To learn more about these animals—including their occurrence and relative abundance in the forests we manage in coastal Northern California—our biologists partnered with biologists at Humboldt State University to conduct several studies. Results indicate that tree voles are patchily distributed in managed Douglas fir forests—specifically those aged approximately 20 years or older. While there is still much to learn about the habitat needs of this species, they appear to benefit from many conservation measures originally implemented to protect the spotted owl.

Photo by Michael Durham

The southern torrent salamander is a small, stream-breeding salamander found in the uppermost headwaters of streams and seeps and that requires cold water with clean gravel to live and breed. Our studies have determined that the species is particularly abundant in our California Timberlands, despite historical unregulated timber harvesting activities that affected much of its habitat.

In 1994, the salamander was petitioned for listing as a threatened species under the California Endangered Species Act. In response, Green Diamond’s predecessor—Green Diamond Timber Company—helped lead the development of a program to train foresters and biologists in the proper identification and protection of the species and its habitat. These efforts contributed to the salamander not being listed as a threatened species, and today, we continue to focus on education and training aimed at the salamander’s continued protection.

In addition to birds and mammals, there are several amphibian species that are thought to be sensitive to land management activities and primarily associated with old-growth forests. For instance, the tailed frog is a small, stream-breeding amphibian that calls our timberlands home and is the only frog in North America to have internal fertilization. Its larvae are equipped with sucker-like mouths that enable them to cling to rocks and boulders in fast-flowing headwater streams, and, like the torrent salamander, it requires streams with cold water and clean gravel and cobble.

Through research and monitoring, we have identified potential threats to this species that timber harvesting activities pose and adjusted our practices to support the tailed frog’s survival. To date, some of the most robust populations of tailed frogs have been documented on land under Green Diamond’s ownership. It’s an example of how studies on forest amphibians—which have taken place on our timberlands since 1993—continue to inform our understanding and conservation practices.

Salmon and Trout Fisheries

The streams that run through our California Timberlands are the spawning and rearing grounds for many species of salmon and trout. Most of these species—including coho, chinook and steelhead—are anadromous, meaning they return from the ocean as adults to spawn in freshwater. While much of their life cycle takes place in salt water, we can influence their freshwater environment. With that in mind, we work to ensure that our timber operations don’t negatively impact these species’ spawning and rearing habitat.

Throughout our California operations, we have initiated a variety of surveys and fish monitoring programs to assess the quality of salmon habitats and track juvenile salmon populations. Our goal is to ensure that conditions for spawning and rearing salmon remain suitable or improved, and to document changes in fish populations over time.

The Phases of Anadromous Salmon Monitoring

Juvenile fish monitoring

As juvenile salmon emerge from their nests to occupy available rearing habitats, we track their survival rate through snorkeling and fishing surveys.

Fall and Winter:
Spawning surveys

Adult salmon leave the ocean and return to our streams to spawn. To estimate their population, our biologists survey the number of spawning salmon and search the gravel for evidence of their nests.

Out-migration trapping

Smolts, or young fish, prepare to leave our streams and begin their adult lives in the ocean. Using a catch-and-release trapping technique, we estimate the number of juvenile fish that ultimately survived in the freshwater environment and made it to this stage.

These studies greatly enhance our understanding of salmon spawning and rearing habitats. However, we can’t determine viability based on changes in population data alone. To gain a deeper understanding, we also monitor critical habitat attributes, such as the temperature of our freshwater streams. Using remote data recorders, we have generated hundreds of water temperature profiles on nearly 100 fish-bearing streams. We use the same technology to monitor water temperature in our headwater amphibian streams. In both cases, the results indicate that our water temperatures are generally ideal.


From the Pacific Northwest to our Southeast operations, our forests support a vibrant array of plant species. Some of these species are classified as rare or have potential sensitivities to timber harvesting practices. To help protect them, for example, we have conducted pre-disturbance floristic surveys in California of all Timber Harvest Plans on our timberlands periodically since 2001. Our botanists also survey unique features—such as grasslands, rock outcrops, lakes, wetlands, serpentine ridges and mountains—to better understand plant landscapes and the ways various species are distributed.

Protecting Rare Plants on Our California Timberlands

In California, we have detected dozens of rare plant taxa in our forests. For all plants with a California Rare Plant Rank of 1 or 2, we develop and implement protective measures to mitigate the impact of our operations on these species. Each year, we submit all sensitive and uncommon plant data, as well as information on the health, vigor and overall quality of many additional plant populations, to the California Natural Diversity Database.

View a listing of sensitive and uncommon plant taxa that we have identified on our California Timberlands.