Ottmar, Roger D.; Vihnanek, Robert E.; Wright, Clinton S.; Olson, Diana L. 2004. Stereo photo series for quantifying natural fuels. Volume VII: Oregon white oak, California deciduous oak, and mixed-conifer with shrub types in the Western United States. PMS 839. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 75 p.

Two series of single and stereo photographs display a range of natural conditions and fuel loadings in deciduous oak woodland and savannah ecosystems in Washington, Oregon, and California. An additional series of single and stereo photographs displays a range of natural conditions and fuel loadings in mixed-conifer with shrub ecosystems in southwestern Oregon. Each group of photos includes inventory data summarizing vegetation composition, structure, and loading; woody material loading and density by size class; forest floor depth and loading; and various site characteristics. The natural fuels photo series is designed to help land managers appraise fuel and vegetation conditions in natural settings.

Keywords: Woody material, biomass, fuel loading, natural fuels, western deciduous oaks, mixed-conifer, blue oak, Quercus douglasii, buckbrush, Ceanothus cuneatus, California black oak, Quercus kelloggii, California live oak, Quercus agrifolia, Douglas-fir, Pseudotsuga menziesii, Engelmann oak, Quercus engelmannii, greenleaf manzanita, Arctostaphylos patula, Jeffrey pine, Pinus jeffreyi, Oregon white oak, Quercus garryana, Pacific madrone, Arbutus menziesii, ponderosa pine, Pinus ponderosa

COOPERATORS
This publication was developed by the USDA Forest Service, Pacific Northwest Research Station, Fire and Environmental Research Applications team with funding provided, in part, by the Joint Fire Science Program.

ACKNOWLEDGMENTS
Special recognition is due John Szulc, Bureau of Indian Affairs, Yakama Agency; Gary McCausland, Department of Defense, Fort Lewis; Jock Beall, Chris Seal, and Karen VisteSparkman, U.S. Fish and Wildlife Service, Willamette Valley National Wildlife Refuge Complex; David Peter, USDA Forest Service, Pacific Northwest Research Station, Olympia Forestry Sciences Laboratory; Mark Stromberg, University of California-Berkeley, Hastings Reservation; Don Garwood, USDA Forest Service, Angeles National Forest; Tom White, USDA Forest Service, Cleveland National Forest; John Dinwiddie and Mitch Maycox, Bureau of Land Management, Medford District. We appreciate being allowed access to Yakama Indian Nation land for three of the Oregon white oak sites. Elizabeth Barker, Tommy Brooks, Matt Cerney, Tim Davis, Steve Duex, Pete Hockett, Vanessa Kenoyer, Jared Mathey, Jennifer McCormick, Crystal Raymond, Nicole Troyer, and David Wright, USDA Forest Service, Pacific Northwest Research Station, Pacific Wildland Fire Sciences Laboratory worked on this project in the field and in the laboratory.

AUTHORS
Roger D. Ottmar and Clinton S. Wright are research foresters, Robert E. Vihnanek is a supervisory forester, and Diana L. Olson is a forester, USDA Forest Service, Pacific Northwest Research Station, Pacific Wildland Fire Sciences Laboratory, 400 North 34th Street, Suite 201, Seattle, Washington 98103.

PHOTOGRAPH AND INFORMATION ARRANGEMENT The photographs and accompanying data summaries are presented as single sites organized into three series.  Each site contains the wide-angle (50 mm) photograph, general site and stand information, forest floor information, summaries of overstory structure and composition, understory vegetation structure and composition, and dead and down woody material loading and density by size class.

Figure 1--Photo series sample area layout. Forty random azimuth line transects (one at each point on the 30- and 150-foot arcs, and two at each point on the 60-, 90-, and 120-foot arcs) and 10-15 clipped vegetation plots (two to three per arc) were located within the sample area. Trees, shrubs and seedlings were inventoried on 12 systematically located sample plots.

SITE AND STAND INFORMATION
The camera point of each site was located with a global positioning system (GPS) receiver using the WGS-84 datum. Aspect and slope, where reported, were measured with a compass and clinometer, respectively. Ecological community classification (to the alliance or association level; NatureServe 2003), an indicator of current vegetation composition, was assigned for all oak sites. Plant association, based on the potential natural vegetation concept (Atzet et al. 1996), was assigned for all of the mixed-conifer with shrub sites. In addition, Society of American Foresters (SAF) cover type (Eyre 1980), an indicator of current vegetation composition was assigned for all sites. When available, the fire history of each Oregon white oak site was included, based on communications with local land managers.

Tree, seedling, and understory species (shrub, forb, and graminoid species) present at a site are listed in order of abundance.¹ The listing of understory species was not meant to be a complete vegetation inventory and may represent only a portion of the actual species richness of the sampled areas. Crown closure was measured with a spherical densiometer (four readings around each of 12 systematically located points), or with a forest densitometer (95 systematically located points). Tree and seedling composition and density were determined either by a total inventory of the sample area, or estimated by using twelve 0.005-acre circular plots; all trees less than 4.5 feet tall were considered seedlings.

For the mixed-conifer with shrub series, graminoid and forb heights were measured at 25 points located systematically throughout the sample area, and shrub height was calculated as an average of all shrubs measured in 12 systematically located 0.005-acre circular plots. Understory vegetation biomass was determined by sampling 12 square, clipped vegetation plots (10.76 square feet each) also located systematically throughout the sample area (fig. 1). All live and dead understory vegetation (except for Amelanchier alnifolia, Arctostaphylos patula, and Ceanothus cuneatus) within each square plot was clipped at ground level, separated, and returned to the laboratory for oven drying. Understory vegetation and other collected material were oven dried at a minimum of 158 °F for at least 48 hours before weighing and determination of area loading. The biomass of shrub species of large stature (i.e., A. alnifolia, A. patula, and C. cuneatus) was calculated by using site- and species-specific allometric equations and added to the biomass of all other shrub species determined from clipped vegetation plots.

1See below for a list of scientific and common species names used in this volume.

FOREST FLOOR INFORMATION
Litter and duff depth were calculated as the average of measurements taken every 5 feet between the 30- and 150-foot arcs of the three center transects for a total of 75 measurements (fig. 1). The depth of the litter and duff was calculated as an average of the depth only where litter or duff was encountered during sampling (null values, or points where litter or duff were absent, are not included in the average). Therefore, the depths reported for litter and duff are not unit-wide averages, and do not necessarily sum to total depth. Loading was calculated from bulk density values derived from field measurements or through collection of material in twelve 10.76 square foot plots.² Constancy, an indicator of how consistently the various forest floor components occur in the sample area, is expressed as a percentage of the total number of measurements. The constancy of exposed mineral soil at each site is reported with the forest floor component constancies for the two oak series; in cases where the total forest floor and the mineral soil constancy do not sum to 100 percent, the remainder is grass-dominated surface material with no duff. The amount of exposed mineral soil at each site for the mixed-conifer with shrub series can be estimated by subtracting the constancy of the total forest floor from 100 percent.

2Forest floor bulk density values used for each material type appear under "Notes to Users" for each series.

UNDERSTORY VEGETATION
Understory species coverage was estimated by using line intercept transects (Canfield 1941). Where species-specific coverage is not reported, understory vegetation coverage was estimated by lifeform category (shrub, forb, or graminoid) by using the line intercept transects. Understory vegetation heights were measured at 25 points located systematically throughout the sample area. Understory vegetation biomass was determined by sampling 12 square, clipped vegetation plots (10.76 square feet each) also located systematically throughout the sample area (fig. 1). All live and dead understory vegetation within each square plot was clipped at ground level, separated, and returned to the laboratory for oven drying. Understory vegetation and other collected material were oven dried at a minimum of 158 °F for at least 48 hours before weighing and determination of area loading. At one site (CDO 07), shrub coverage and biomass were measured in twelve 0.005-acre circular plots. Biomass was calculated from a growth-form-based allometric equation (tall shrubs; Brown 1976).

WOODY MATERIAL 
Measurement techniques used for inventorying dead and down woody material were patterned after the planar intersect method outlined by Brown (1974) and described by Maxwell and Ward (1980). Forty transects of random azimuth starting at 25 systematically located points within the sample area were used to determine woody material loading and density (fig. 1). Woody material data are reported by size classes that correspond to timelag fuel classes used in fire behavior modeling (see, for example, Burgan and Rothermel 1984).³ Woody material in 10-hour, and 100-hour-and-larger size classes was tallied on transects that were 10 feet and 30 feet long, respectively. The decay class and the actual diameter at the point of intersection were measured for all pieces >3 inches in diameter. All woody material <=3 inches in diameter was considered sound. Woody material loading and woody material density were calculated from relationships that use number of pieces intersected and transect length (and wood specific gravity for loading) developed by Brown (1974) and Safranyik and Linton (1987), respectively. Woody material loading in the 1-hour size class (and the 10-hour and 100-hour size classes for many of the sites) was determined by collecting, oven drying, and weighing all pieces in twelve 10.76-square-foot plots. When woody material >3 inches in diameter was scarce, a total inventory within the sample area was conducted to determine loading and density estimates. Measurements were taken to determine log volume, and wood specific gravities were applied to the volume to calculate loading.

3>1-, 10-, 100- and 1000-hour timelag fuels are defined as woody material 0.25 inch, 0.26-1.0 inch, 1.1-3.0 inches, and >3.0 inches in diameter, respectively.

SAPLINGS AND TREES
Overstory tree and sapling composition and density were determined either by a total inventory of the sample area, or were estimated by using twelve 0.005-acre circular plots located systematically throughout the sample area (fig. 1). Tree measurement data were summarized by diameter at breast height (d.b.h.)⁴ size class and by tree status (live, dead, or all trees for the two oak series). The two or three most abundant tree species for each size class are listed with their relative density. Height to crown base (reported as ladder fuel height in previous photo series volumes) was defined as the height of the lowest, continuous live or dead branch material of the tree canopy, and height to live crown was defined as the height of the lowest continuous live branches of the tree canopy. Live crown mass (branchwood and foliage) was calculated from species- and size-specific allometric equations (Brown 1978, Snell 1979, Snell and Little 1983) for the mixed-conifer with shrub series. Crown mass equations for Quercus kelloggii, Pinus ponderosa and Thuja plicata were substituted for Quercus garryana, Pinus lambertiana, and Calocedrus decurrens, respectively.

4D.b.h. is measured 4.5 feet above the ground.

SHRUB DIMENSIONS AND BIOMASS
Individual plants of all large shrub species that dominated the mixed-conifer with shrub sites (i.e., Amelanchier alnifolia, Arctostaphylos patula, and Ceanothus cuneatus) were measured in circular plots, or if shrub density was low, in the entire sample area. The density and percentage of all stems that were dead is based on the number of plants rooted in twelve 0.005-acre circular plots (or in the entire sample area if shrub density was low). Crown area was calculated from crown breadth (i.e., the average of the maximum crown diameter, and the widest point perpendicular to the maximum crown diameter). Basal diameter (or basal area of multistemmed plants) was measured above the root collar. The average and maximum height of all sampled individuals of a given species is also reported.

Allometric equations were developed from Arctostaphylos patula and Ceanothus cuneatus plants growing on several of the sites sampled for the mixed-conifer with shrub series (Wright et al. unpublished data).⁵ Twenty-five live A. patula and C. cuneatus plants representing a range of sizes were measured, harvested, and separated into live and dead foliage, 0.25 inch, 0.26-1.0 inch, >1.0 inch diameter stem and branch material. All separated material was oven dried and weighed in the laboratory. Separate equations to predict the biomass of live and dead foliage, and live and dead woody material by size class for each species were developed to best estimate shrub loading. Amelanchier alnifolia biomass was estimated from equations and size class relationships in Brown (1976).

The biomass of each foliage and woody material size category was computed for all measured plants to determine area loading in each category for each species. The "Other species" category includes the large shrub species Amelanchier alnifolia, and smaller shrub species whose biomass was estimated in the clipped vegetation plots (primarily Toxicodendron diversilobum, Symphoricarpos spp., Mahonia aquifolium, Rosa spp., and Lonicera spp.).

5Data on file at the U.S. Department of Agriculture, Forest Service, Pacific Wildland Fire Sciences Laboratory, Seattle, WA.

SPECIES LIST
Scientific and common species names are from NRCS (2002) and Pojar and MacKinnon (1994).

LITERATURE CITED

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Brown, J.K. 1978. Weight and density of crowns of Rocky Mountain conifers. Res. Pap. INT-197. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 56 p.

Brown, J.K. 1976. Estimating shrub biomass from basal stem diameters. Canadian Journal of Forest Research 6: 153-158.

Brown, J.K. 1974. Handbook for inventorying downed woody material. Gen. Tech. Rep. INT-16. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 24 p.

Burgan, R.E.; Rothermel, R.C. 1984. BEHAVE: fire behavior prediction and fuel modeling system--FUEL subsystem. Gen. Tech. Rep. INT-167. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 126 p.

Canfield, R.H. 1941. Application of the line interception method in sampling range vegetation. Journal of Forestry 39: 388-394.

Eyre, F.H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [+ map].

Maxwell, W.G.; Ward, F.R. 1980. Guidelines for developing or supplementing natural photo series. Res. Note PNW-358. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 16 p.

Natural Resources Conservation Service [NRCS]. 2004. The PLANTS Database. Version 3.5. https://plants.usda.gov. [U.S. Department of Agriculture, National Resources Conservation Service, National Plant Data Center, Baton Rouge, LA.] (9 April 2004).

NatureServe. 2002. NatureServe Explorer: An online encyclopedia of life, Version 1.8. https://www.natureserve.org/explorer. [NatureServe, Arlington, VA.] (17 October 2003).

Pojar, J.; MacKinnon, A. 1994. Plants of the Pacific Northwest coast: Washington, Oregon, British Columbia and Alaska. Vancouver, BC: BC Ministry of Forests and Lone Pine Publishing. 527 p.

Safranyik, L.; Linton, D.A. 1987. Line intersect sampling for the density and bark area of logging residue susceptible to the spruce beetle, Dendroctonus rufipennis (Kirby). Inf. Rep. BC-X-295. Victoria, BC: Canadian Forestry Service, Pacific Forestry Centre. 10 p.

Snell, J.A.K. 1979. Preliminary crown weight estimates for tanoak, black oak and pacific madrone. Res. Note PNW-340. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 4 p.

Snell J.A.K.; Little, S.N. 1983. Predicting crown weight and bole volume of five western hardwoods. Gen. Tech. Rep. PNW-151. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 37 p.