California covers about 100 million acres and about 40% of the State is forest. National Forest System lands, managed by the US Forest Service, cover in excess of 18 million acres. The remainder of the forested land is a mix of other federal government (BLM, NPS), private, tribal and state ownerships.
Forest operations such as logging, thinning, fuels reduction programs and ecosystem restoration create a huge amount of woody biomass. Some of this is brought out of the forest for use, but as much as half of the biomass is left in the forest. Often it is piled and burned creating pollution and the risk of starting a wildfire.
In practice the cost of removing woody biomass from the forest is often too expensive to justify it. It often requires a subsidy from the landowner or the removal of other higher value products, such as saw logs, to be cost effective.
A cost effective source of readily available woody biomass can be found at sawmills in the form of bark, sawdust, wood chips, wood shavings and cull logs. This material is currently utilized in a number of markets including fuel for power plants, landscape amendments, compost, animal bedding, pulp and panel board.
Chart showing distribution of the 32.4 million BDT biomass technically available for use in California in 2007. (Source: California Biomass Collaborative Forum)
The California Biomass Collaborative carried out a study of the potential biomass resource in California. In addition to forest and sawmill sources woody biomass in California includes chaparral, agricultural waste (including nut shells, olive pits, grape pomace, orchard trimmings and removal) and municipal waste sources (post consumer, post industrial and green waste such as tree trimmings etc). The study estimated that there were 32.4m bone dry tons (BDT) technically available from these sources in California.
Currently the biggest users of woody biomass in California are biomass power plants (see Electricity), composting and other landscaping markets.