• What is the Natural Fuels Photo Series?
• Why is the Photo Series Neeeded?
• How was the Photo Series Developed?
• Photographs
• Using the Photo Series
• Metric Conversions
• Literature Cited

WHAT IS THE NATURAL FUELS PHOTO SERIES?
The first phase of the natural fuels photo series was a collection of six volumes, each representing a region of the United States (Volumes I-VI). Additional phases of the natural fuels photo series included new volumes (Volumes VII-XII) and supplemental volumes (Volumes IIa, Va, and VIa). Volume I included sites in mixed-conifer, western juniper, sagebrush, and grassland ecosystems and volume XI included sites in sagebrush-steppe and old-growth forest suitable for nesting in the Pacific Northwest. Volume II included sites in black and white spruce ecosystems and volume IIa included sites in hardwood ecosystems undergoing succession to spruce in Alaska. Volume III included sites in lodgepole pine, quaking aspen, and gambel oak ecosystems in the Rocky Mountains. Volume IV included sites in pinyon-juniper, sagebrush, and chaparral ecosystems in the Southwest. Volume V included sites in red and white pine, northern tallgrass prairie, and mixed oak ecosystems, and volume Va included sites in jack pine ecosystems in the Midwest. Volume VI included sites in longleaf pine, pocosin, and marsh grass ecosystems and volume VIa included sites in sand hill, sand pine scrub, and white pine-invaded hardwood ecosystems in the Southeast. Volume VII included sites in Oregon white oak, California deciduous oak, and mixed-conifer with shrub ecosystems in Washington, Oregon, and California. Volume VIII included sites in hardwood, pitch pine, and red spruce/balsam fir ecosystems in the Northeast. Volume IX included sites in oak/juniper ecosystems in southern Arizona and New Mexico. Volume X included sites in sagebrush with grass and ponderosa pine-juniper ecosystems in central Montana. An unnumbered volume included grassland, shrubland, woodland, and forest ecosystems in Hawaii.

In the printed publications, sites generally include wide-angle and stereo-pair photographs supplemented with information on living and dead fuels, vegetation, and stand structure and composition within the area visible in the photographs (fig. 1).

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 (one to three per arc) were located within the sample area. Trees, shrubs and seedlings were inventoried on 12 systematically located sample plots.

WHY IS THE PHOTO SERIES NEEDED?
These photo series are land management tools that can be used to assess landscapes through appraisal of living and dead woody material and vegetation (i.e., fuels) and stand characteristics. Once an assessment has been completed, stand treatment options, such as prescribed fire, mechanical or hand fuel reduction, or harvesting, can be planned and implemented with greater detail and precision to better achieve desired effects while minimizing negative impacts on other resources.

The photo series has application in several branches of natural resource science and management. Inventory data such as these can be used as inputs for evaluating animal and insect habitat, nutrient cycling, and microclimate, for example. Fire managers will find these data useful for predicting fuel consumption, smoke production, fire behavior, and fire effects during wildfires and prescribed fires. In addition, the photo series can be used to appraise carbon sequestration, an important factor in predictions of future climate, and to link remotely sensed signatures to live and dead fuels on the ground.  The photos have proved useful in discussions of proposed treatment options with citizens, public officials, and agency administrators. They are also a practical communication tool in the preparation, advertisement, and administration of fuel treatment contracts.

Ground-based inventory procedures that directly measure site conditions (e.g., fuel loading and arrangement, vegetation structure and composition, etc.) exist for most ecosystem types and are useful when a high degree of accuracy is required. Ground-based inventory is time consuming and expensive, however. Photo series can be used to make quick, easy, and inexpensive determinations of fuel quantities and stand conditions when less precise estimates are acceptable.

HOW WAS THE PHOTO SERIES DEVELOPED?
Sites photographed for the series were selected to show a range of conditions of several site attributes depending on the ecosystem type. Photographs were taken, and fuel loading, stand structure, and composition data were collected by using the procedures of Maxwell and Ward (1980) as a guide.

• In Volume I, the mixed-conifer sites show ranges of down and dead woody material loading and insect-related tree mortality. The western juniper and sagebrush sites depict varying degrees of western juniper and sagebrush density, respectively. The grassland sites represent a range of total biomass.
• In Volume II, both the black spruce and white spruce sites represent a range of tree sizes and densities. In addition, the white spruce sites show a range of woody material loadings.
• In Volume IIa, sites were selected to represent a range of conditions in Alaska hardwood ecosystems undergoing succession to spruce.
• In Volume III, photo series represent ranges of down and dead woody material loading, understory composition, and overstory development.
• In Volume IV, photo series show ranges of biomass, species composition, plant size, and plant density.
• In Volume V, the midwest red and white pine sites and the mixed oak sites show ranges of down and dead woody material loading. The northern tallgrass prairie sites represent a range of total biomass.
• In Volume Va, sites were selected to show ranges of down and dead woody material loading, understory composition, and overstory development.
• In Volume VI, the longleaf pine sites show ranges of down and dead woody material loading and understory development. The pocosin sites depict ranges of vegetation height and biomass loading, and are separated into two subseries, one dominated by woodland species and the other dominated by shrub species. The marshgrass sites represent a range of total biomass loading. 
• In Volume VIa, the sand hill sites show a range of overstory conditions, with a specific focus on turkey oak occurrence as a percentage of the tree composition. The sand pine scrub sites also represent a range of overstory conditions, primarily of the sand pine component. The hardwoods sites depict a range of understory development conditions with respect to varying degrees of Eastern white pine invasion. The supplemental longleaf pine and marshgrass sites capture high biomass conditions in their respective types.
• In Volume VII, the Oregon white oak sites range from savannah to woodland types, the deciduous oak sites in California show a range of savannah types, and the mixed-conifer with shrub sites represent a range of shrub coverage, species composition, and shrub size conditions.
• In Volume VIII, sites were selected to represent a range of structural conditions in hardwood types dominated by beech, birch, and maple. The pitch pine sites range from those dominated by oak-brush with only minimal pine presence to woodland and forest types with mature trees, and are ordered by amount of understory vegetation biomass. The red spruce/balsam fir sites show a range of stand structures and are ordered by the density of the overstory cohort.
• In Volume IX, sites were selected to represent a range of conditions in oak/juniper woodland ecosystems in southern Arizona and New Mexico and are ordered by increasing density of trees greater than 4 inches in diameter at breast height (d.b.h.).
• In Volume X, sites were selected to represent a range of conditions in sagebrush with grass and ponderosa pine-juniper forest ecosystems in the Missouri Breaks region of central Montana. The sagebrush with grass sites represent a range of shrub coverage, species composition, and shrub size conditions and are ordered by total aboveground biomass. The ponderosa pine-juniper sites show a range of woodland and forested stand conditions and are ordered by tree density.
• In Volume XI, sites were selected to represent a range of conditions in sagebrush-steppe ecosystems in eastern Oregon and old-growth forest suitable for northern spotted owl nesting habitat in Oregon and Washington. The sagebrush-steppe sites are organized into three series: sagebrush with grass, sagebrush with western juniper, and sagebrush with ponderosa pine. Each series is organized by biophysical setting and succesional stage as defined by the LANDFIRE National Vegetation Dynamics Model descriptions (Rollins and Frame 2006). 
• In Volume XII, sites provide a basis for appraising and describing woody material, vegetation, and stand conditions in many post-hurricane forest types in the Gulf and Atlantic coasts of the Southeast United States.
• In Volume XIII, sites show a range of conditions for grassland, shrubland, oak-bay woodland, and eucalyptus forest in the East Bay area of California.
• Hawaii sites were selected with the aid of local managers and researchers to represent some of the variation in environmental and botanical conditions encountered on government lands in Hawaii. Owing to sampling constraints and the diversity of habitats in Hawaii, however, not all vegetation types present in the islands were sampled.

PHOTOGRAPHS
The digital photo series displays one wide-angle photograph per site.  Most printed volumes also include stereo-pair photographs.  The marker in these photographs is a 1-foot square, and the pole is painted in contrasting colors at 1-foot intervals to provide scale. The pole is 30 feet from the camera. The summary data relate to the field of view of the stereo-pair photograph and are based on measurements taken in the sample area only (see fig. 1). No sampling occurs in the foreground between the camera and the sign.

USING THE PHOTO SERIES
The natural fuels photo series is a tool for quickly and inexpensively evaluating a variety of fuel and vegetation conditions. Because of its ease of use, however, care must be taken when evaluating field sites to compare only with photo series sites that are appropriate matches. It is acceptable, however, to use the data from more than one site from the photo series when evaluating a site in the field (e.g., woody material loading from one site in the photo series and tree density from another site in the photo series to best match the conditions of a given field site).

Make a visual inventory of the site by observing fuel and stand conditions within the field of view and comparing them with the stereo-pair photographs as follows, remembering that the data tables relate to the area behind the sign in the stereo-pair photographs:

• Observe each characteristic for a specific size class of woody material on the ground (e.g., 3.1 to 9.0-inch woody material loading).
• Select a photo series site (or sites) that nearly matches (or brackets) the observed characteristics.
• Obtain the quantitative value for the characteristic being estimated from the data summary accompanying the selected photo series site, or interpolate a value between sites.
• Repeat these steps for each size class or stand characteristic of interest.

The total loading or stand condition can then be calculated by summing the estimates. If the site being inventoried has areas with obvious differences in woody material or stand conditions, the user should make separate determinations for each area and then weight and cumulate the loading for the whole site.

Characteristics not distinguishable in the photographs are forest floor depth, loading, and bulk density, and proportions of sound and rotten woody material. If values for these characteristics are desired in the inventory, they must be derived from independent sampling or observations.

The 20 National Fire-Danger Rating System fuel models (Burgan 1988, Deeming et al. 1977) and the 13 original (Albini 1976) or 40 new (Scott and Burgan 2005) fire behavior fuel models are very general in content and broadly applied.  Each photo series encompasses a wider range of conditions, and individual sites represent fuel characteristics at greater resolution than can be gained by using fuel models; consequently, we chose not to assign one of these existing fuel models or types to individual sites in the photo series. The photo series was designed to provide sufficient fuel and vegetation data from which managers could generate their own customized fuel models or types.

LITERATURE CITED

Albini, F.A. 1976. Estimating wildfire behavior and effects. Gen. Tech. Rep. INT-30. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 92 p.

Burgan, R.E. 1988. 1988 revisions to the 1978 national fire-danger rating system. Res. Pap. SE-273. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 39 p.

Deeming, J.E.; Burgan, R.E.; Cohen, J.D. 1977. The national fire-danger rating system--1978. Gen. Tech. Rep. INT-39. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 63 p.

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.

Rollins, M.G.; Frame, C.K., tech. eds. 2006. The LANDFIRE prototype project: nationally consistent and locally relevant geospatial data for wildland fire management. Gen. Tech. Rep. RMRS-GTR-175. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 416 p.

Scott, J.H.; Burgan, R.E. 2005. Standard fire behavior fuel models: a comprehensive set for use with Rothermel’s surface fire spread model. Gen. Tech. Rep. RMRS-GTR-153. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 72 p.