Forest Inventories In California Include More Than Trees

• Here are some key findings from the report:
• Forests cover about a third of the state's 100 million acres;19 million acres is publicly managed.
• Houses built in the wildland-urban interface account for most of the housing growth in the state over the last 10 years implying that forest managers will be tasked with fire hazard reduction, prevention, and suppression on an increasing area.
• Insects, diseases, air pollution, and fire shape the forested California landscape. More than 200,000 forested acres burned on average annually between 2001 and 2005.
• Modeling crown fire potential under extreme weather conditions showed that fire would occur as a surface or conditional surface fire in 72 percent of forests, and as a passive crown fire in only 20 percent of forests.
• In most cases, fuel treatment may require only the removal of ladder fuels (smaller diameter trees) rather than thinning mature trees in the upper canopy.
• The capacity of wood-using bioenergy facilities has increased resulting in California facilities being able to generate over 470 megawatts of electricity.
• Carbon storage for live and dead trees, and downed wood are highest in redwood and Douglas-fir forest types when evaluated on a per-acre basis.
• More than 13 million acres of forest land is privately held; about 5 million acres is owned by industry, and 7 percent of this acreage is managed by a timber investment management organization (TIMO) or real-estate investment trust (REIT) which may manage the land for a variety of investment purposes.

The data from the FIA reports are used by state, federal, and private land managers, investors, and others for a variety of purposes including the assessment of fuels and potential fire hazard, biomass and carbon storage, the effects of insects and disease, growth and mortality, wildlife habitat, plant diversity, and the supply of goods and services.

Since the 1930s, the U.S. Forest Service has conducted inventories of private lands throughout the United States. In the early days, inventories focused primarily on trees: how much timber was out there? Today's inventory is still about measuring and counting trees, but it also accounts for understory vegetation, down woody material, lichens, damage caused by insects and disease, and more.

Whereas the original inventory design produced resource bulletins about every 10 to 12 years from data collected over a 2- to 3-year period, today's inventory in the Western United States is conducted on a 10-year cycle where 1/10 of the field plots are measured annually on public and private forest land. Data are now posted each year and summary reports are issued every 5 years.

The frequency was directed by Congress through language in the 1998 Farm Bill, according to ecologist Joseph Donnegan, technical editor of the Oregon report and a member of the PNW Research Station's Forest Inventory and Analysis (FIA) Program.

"Instead of the 10-year timber reports we used to produce, we now post data annually and write a report every 5 years that covers a much broader range of topics that regularly appear in the news. The idea was not only to provide data on an annual basis, but to be nationally consistent in how we conduct inventory and monitoring. Previously, different FIA regions were using different methodologies," explains Donnegan. "The results were specific for that region or part of the country, but comparisons and analyses weren't easily made owing to the variety of techniques used. The national Forest Inventory and Analysis Program now uses standard measurement and analysis techniques."

Standardization and the move to annual data availability occurred through the efforts of client input via blue-ribbon panels. Congress responded with Farm Bill directives and by allocating partial funding to begin progress toward a Forest Inventory and Analysis system that is national in scope.

The California report was produced by the Pacific Northwest FIA Program which conducts forest inventories in Alaska, California, Oregon, Washington, Hawaii, and the Pacific Islands.

There are four FIA Programs in the research branch of the U.S. Forest Service: the Pacific Northwest, Interior West, Northern, and Southern. The mission of each of the programs is to provide information on the status and trend in our Nation's forests to resource managers, scientists, conservationists, investors, and the public.