Utilization opportunities and challenges

John R. Shelly, PhD

Table 1: Estimated Growing Stock Volume of Hardwoods Typically Found in the Timberland and Woodland Regions of Calif.
Common Name	Scientific Name	Total Volume (million ft3)
TIMBERLAND SPECIES
California black oak	Quercus kelloggii	2420
Tanoak	Lithocarpus densiflora	2167
Pacific madrone	Arbutus menziesii	1272
California bay laurel	Umbellaria californica	270
Alder	Alnus spp.	267
Oregon white oak	Quercus garryana	245
Bigleaf maple	Acer macrophyllum	165
California white oak	Quercus lobata	49
Giant chinquapin	Castanopsis chrysophylla	45
Poplar/cottonwood	Populus spp.	14
Oregon ash	Fraxinus latifolia	7
WOODLAND SPECIES
Canyon live oak	Quercus chrysolepsis	1379
Coast live oak	Quercus agrifolia	140
Interior live oak	Quercus wislizeni	70
Quaking aspen	Populus tremuloides	24
Eucalyptus	Eucalyptus spp.	19
Blue Oak	Quercus douglasii	11
Walnut	Juglans hindsii	1
Sycamore	Platanus racemosa	<1

There is a sizable hardwood component to California’s forests (see Table 1). Despite this, the native hardwoods never played an important role in the products produced from the forest. Today the major uses of hardwoods in California are for fuel chips, pulp chips, and firewood, all products that return little value to the landowner. Traditionally, hardwoods have also been a source of food (nuts and acorns), wildlife habitat, timber for local farm and home use, and firewood…but of little commercial value for value-added products.

As we move into the 21st century, an increasing understanding of the science of ecology and societal pressures are causing a reevaluation of our natural resources with an emphasis on sustainable production and improving rural economies. In certain situations, hardwoods may be a viable resource for local needs, specialty products, or perhaps even for a larger commodity market. The high-density hardwoods such as tanoak, madrone, California black oak, and the white oaks may have economic potential. Local products made by artisans, woodworkers and hobbyists prove that high value products can be made from many of these native hardwood species. The high cost of production will likely be a major limiting factor.

Opportunities
Resource—Hardwoods represent an underutilized resource. Hardwood species in California are about 16% of the inventory of standing timber (growing stock volume) and 6% of the sawtimber volume (greater than 11-inch diameter, dbh). Sixty percent of the hardwood inventory is located in the timberland forests and the remaining 40% is found in the rangelands and valley regions. About one-third of the timberland hardwood growing stock is sawlog quality. Harvesting volumes of native hardwoods are not available, but it is likely that sustainable harvesting levels could be increased dramatically.

Demand—California is one of the nation’s major consumer markets for hardwood flooring, furniture, cabinets, and other wood products. Manufacturing these products near the markets can offer distinct economic advantages in low transportation costs. These two factors have created a furniture-manufacturing sector in California that uses more than one million board feet of hardwood lumber per year. However, less than 5% of the total comes from the western U.S. species, and nearly all of that is red alder. Most (about 80%) is shipped from the eastern half of the US and about 10% is imported from tropical regions. Clearly, there is an opportunity for western hardwood lumber if consistent quality can be offered at a competitive price. California furniture manufacturers have a high demand for wood components and sub-assemblies—intermediate products that are well suited to the native hardwood resource.

Economic Development—The growth of an industry to produce wood products from an underutilized resource has the potential to create many jobs in rural communities with a timber resource base. These jobs may offset some of the employment losses resulting from reductions in softwood harvesting and the modernization and closing of sawmills.
Marketing—California hardwoods present unique marketing opportunities, especially in niche markets. There is often a distinct advantage to products that are locally grown and produced. In many cases, the sustainable harvest of California hardwoods may qualify for ecological certification by third party monitors. This certification has the potential to increase the value of a product to customers who place a premium on environmentally sound manufacturing. Even without an additional economic value, it may give a marketing edge over a product that is not certified.

Raw Material Properties—Many of California’s hardwood species compare favorably with the benchmark species of the furniture industry. With the exception of the lower density hardwoods such as poplar, cottonwood, buckeye, and willow, most of the California hardwoods will perform very well in conventional hardwood products. The high-density California hardwoods (specific density > 0.50) have very good machining and finishing properties, and some of the finer textured woods such as madrone and red alder are exceptional. Many of the high-density hardwoods also have unique and interesting grain patterns that add to the appearance value of the wood. All of the moderate to high-density hardwoods also have very good strength properties. A few, such as tanoak, madrone, Oregon white oak, valley oak, and eucalyptus, exhibit very high hardness values making them an exceptional choice for hardwood flooring. A summary of properties for some California hardwoods are listed in Table 2, along with the comparable values for northern red oak, a benchmark species.

Challenges
Manufacturing—There are numerous challenges to manufacturing products from California hardwoods. In some cases, the high density and unique wood properties that may create marketing opportunities often create difficult manufacturing situations. For example, California hardwoods have a reputation for being

Table 2. Properties of Common California Hardwoods Compared with Northern Red Oak
	Specific Density	Machining Quality	Finishing Quality	Hardness (lb)	Tangential Shrinkage (%)	Warp Index
Bigleaf maple	0.44	good	good	850	7.1	1.9
Blue gum eucalyptus	0.63	good	good	1650	15.3	2.0
California bay laurel	0.54	good	very good	1270	8.1	2.9
California black oak	0.50	good	good	1080	7.8	2.1
California white oak	0.60	good	very good	1570	9.8	2.4
Chinquapin	0.44	fair	good	780	7.4	1.6
Madrone	0.61	excellent	very good	1530	13.7	2.4
Oregon ash	0.50	good	very good	1160	8.1	2.0
Oregon white oak	0.66	good	very good	1780	9.0	2.1
Red alder	0.39	very good	very good	620	7.3	1.7
Tanoak	0.59	good	good	1450	12.0	1.9
Northern red oak	0.56	very good	very good	1290	8.6	2.1

hard to dry. Extra care during drying is required with the dense woods that have a tangential shrinkage (tangent to the growth rings) greater than 10% and a warp index greater than 2.0 (Table 2). These woods are expected to have a high frequency of drying defects if they are dried improperly. Tanoak, madrone, and the white oak species are three species with a high tendency to warp and collapse during drying. However, good results can be obtained by drying slowly with good control of the drying conditions. A kiln capable of reaching a temperature of 150ºF (the temperature required to sterilize insect-infested wood) that has a method to reintroduce moisture at the end of drying to relieve stresses can successfully dry any of these hardwoods to the desired final moisture content of 8%.

Marketing—Manufacturers and consumers are largely unaware of California hardwoods. The California Hardwood Initiative, a statewide effort supported by the California Trade and Commerce Agency, California Department of Forestry and Fire Protection, USDA Forest Service and the University of California, has successfully raised the level of awareness but more needs to be done. The commodity lumber markets demand large volumes of lumber, readily available at a competitive price and manufactured to existing industry standards. In contrast, the niche market is more flexible because a specific product or customer is targeted and the product is tailored to the customer’s needs. Availability and quality concerns make it difficult for a new product to enter the commodity market; however, based on the properties and characteristics of the California hardwoods successful niche markets are quite possible.

State of the Industry
A recent survey of hardwood sawmill manufacturers in California revealed 34 sawmills and 60 secondary manufacturers that are currently working with or interested in working with native California hardwoods. The sawmills are exclusively mini-mills, often with portable equipment, with annual productions less than 500 thousand board feet (MBF). Many of these mills produce less than 50 MBF per year. The estimated total production of all the mills in 1999 was only about 4 million board feet. At the time this survey was completed there were two large production softwood sawmills considering limited tanoak productions. These two mills have the potential to dramatically increase the availability of California hardwoods.

Based on the physical and mechanical properties, any of the common hardwood consumer goods could be manufactured from California hardwoods. Some woods are better suited for particular products than other woods and factors such as resource availability, cost of production, and quality of the end product will determine the long-term viability of a California hardwood business venture. These hardwoods present some manufacturing challenges, but the technology exists to address these challenges. With an understanding of some of the fundamental wood properties and basic manufacturing principles, many of these hardwoods can be manufactured into high value products.

For more information and references, see the following references:

Shelly, J. R., D. M. Lubin, and A. Johl. 1999 California Hardwood Industry Profile: Final Report. University of California Forest Products Laboratory Technical Report 35.01.454.

Shelly, J. R. 1998. An Examination of the Oak Woodland as a Potential Resource for Higher-Value Wood Products. In Proceedings: Symposium on Oak Woodlands: Ecology, Management, and Urban Interface Issues. USDA Forest Service General Technical Report PSW-GTR-160.

John R. Shelly is a Cooperative Extension Advisor in Forest Products and Biomass, University of California Forest Products Laboratory, Richmond, CA.