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Climate Risks to California Forests

 Forests in California

There are over 33 million acres of forested lands in California. Forest type, ownership, size, and uses are highly diverse across the state. Within these lands are the world’s oldest, tallest, and most massive trees. The forested watersheds provide over 60% of the water supply and energy to the state’s huge agricultural economy and millions of residents. As stewards of these lands for thousands of years, forests remain integral to the cultures and subsistence of many Native American tribes. These ecosystems generate hundreds of thousands of jobs and billions of dollars in revenue, while providing habitat for rich biodiversity, including black bears, elk, condors, endemic amphibians and reptiles, and abundant insect pollinators. California is home to the top carbon storage ecosystem: coastal redwoods, and its forests are capable of sequestering millions of tons of carbon.

How are climate change and weather variability affecting California’s forests?

Over the past century, fire exclusion and associated management decisions promoted denser forests with higher fuel loads. Today, California’s forests are experiencing increasing stress and disturbance as a result of interactions among the cascading impacts of climate change, dense forest conditions, and the expansion of the wildland-urban interface.

Climate impacts on CA forests

Changing climatic conditions in California have lengthened the dry season, increased temperatures, insect pressures, and plant moisture stress, and reduced soil moisture. Research shows that changes in forest composition or type are likely as temperature and moisture suitability shifts northward and upward in elevation. Increased frequency and duration of drought, coupled with bark beetle infestations, may result in large-scale tree mortalities.


How is the Climate Hub helping to sustain California's forests?   

The California Climate Hub works with federal, state, and local partners develop and deliver science-based, region-specific information and technologies to agricultural and natural resource managers to enable climate-informed decision-making. The Hub provides actionable information with the mission to support climate-resilient forests, facilitate communication, and support co-production of knowledge, tools, and products. Examples of resources and products developed by the Hub include:

Climate Hub Forest Products


A Climate Change Primer for Forest Managers in the Sierra Nevada

The primer was developed to provide forest managers working in the Sierra Nevada with a basic overview of the relevant scientific issues bearing on forest management in this region.  The emphasis will be on the challenges around climate change adaptation but this document will cover the range of important research findings bearing on forest management today. A link to the primer can be accessed here.


A Climate-Wise Reforestation Toolkit

The toolkit consists of three resources that can be used individually or together to inform reforestation decisions in context of tree mortality and climate change. First, the reforestation prioritization tool was designed to help locate where to reforest based on the level of tree mortality and other user-defined variables. Second, the post-drought stand condition tool was designed to allow users to explore newly changed conditions on their National Forest area of interest. And finally, to help guide planting techniques, we have compiled a brief best management practices (BMPs) summary. Learn more and access the toolkit here


A Menu of Adaptation Strategies and Approaches for Climate-Adaptive California Forest Ecosystems

The menu of adaptation strategies and approaches offers flexible, yet tangible, options for integrating climate change considerations into California forest management. It reflects the context of the state's forests and is informed by a synthesis of California forest adaptation literature. Read more and access a link to the complementary forest Adaptation Workbook here.


Success Through Partnerships

In service of the state’s working lands, the Climate Hub works with partners across federal and state agencies, universities, and industry to help enable climate-informed decision making and advance the adaptive capacity for California’s forests and woodlands to meet the challenges of the future.  Partnership examples include:

  • workshop collaborations with TNC to assess regional perspectives on use of nature-based solutions on natural working lands for achieving carbon neutrality.
  • co-leading the Science Advisory Panel of the Forest Mgmt. Task Force to deliver vetted scientific opinions to the strategies and goals of the Task Force
Hub forest partners


Want to print this information or download a PDF to pass along?

Access the 2-page fact sheet here. 

Have more questions on this topic?

Reach out to Hub Director, Steven Ostoja or Hub Climate Adaptation Specialist for forestry, Jennifer Smith