Ottmar, Roger D.; Vihnanek, Robert E. 2000. Stereo photo series for quantifying natural fuels. Volume VI: Longleaf pine, pocosin, and marshgrass types in the Southeast United States. PMS 835. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 56 p.

Three series of single and stereo photographs display a range of natural conditions and fuel loadings in longleaf pine, pocosin, and marshgrass types in the Southeast United States. Each group of photos includes inventory information summarizing vegetation composition, structure and loading, and, as appropriate, 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, longleaf pine, Pinus palustris, pocosin, marshgrass.

COOPERATORS
This publication was developed by the USDA Forest Service, Pacific Northwest Research Station, Fire and Environmental Research Applications Group, under contract with the U.S. Department of the Interior.

ACKNOWLEDGMENTS
Special recognition is due Dale Wade, USDA Forest Service, Southern Forest Fire Laboratory; Ron Phernetton, USFWS, Okeefenokee National Wildlife Refuge; Frank Cole, USFWS, Tall Timbers Research Station; Roger Hungerford and Jim Reardon, USDA Forest Service, Missoula-Intermountain Fire Sciences Lab; Joe Scott, Systems for Environmental Research; Tom Crews, USFWS, Alligator River National Wildlife Refuge; Bryan Henderson and Scott Smith, USAF, Seymour Johnson Air Force Base; Jim Durrwachter, USFWS, Florida Panther National Wildlife Refuge; Kevin Walsh, USDI, Big Cypress National Preserve; C. Ross Hinkle and Carlton Hall, Dynamac Corporation; and Frederic Adrian, USFWS, Merritt Island National Wildlife Refuge.

AUTHORS
ROGER D. OTTMAR is a research forester and ROBERT E. VIHNANEK is a supervisory forester, USDA Forest Service, Pacific Northwest Research Station, Forestry 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 information, and, as appropriate for the ecosystem type, summaries of overstory structure and composition, understory composition and loading, shrub structure and loading, litter depth, loading and bulk density, and dead and down woody material loading and density by size class. For the marshgrass sites, all available data are reported as site information.

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 INFORMATION
The camera point of each site was located with a global positioning system (GPS) receiver using the WGS-84 datum. Major species present at a site are listed but represent only a portion of the actual species composition.¹Cover type, an indicator of current vegetation composition, was assigned for each site (Eyre 1980, Shiflet 1994).

For all sites in the longleaf pine and pocosin series site type is reported using local terminology and is typically a reference to the successional or physiognomic status of the site; "rough" includes understory vegetation and forest floor material, and the age indicates the number of years since the last fire occurred at the site. In addition, canopy cover was measured at 12 points in the sample area with a spherical densiometer. Maximum tree height (i.e., the height of the tallest tree sampled) and minimum crown height (i.e., the lowest height to crown base of any tree or sapling sampled) are based on a total inventory of the sample area for the trees in the longleaf pine series and the pocosin shrub subseries, and on twelve 0.005-acre circular plots for the pocosin woodland subseries (fig. 1). The understory vegetation and forest floor loadings reported for the longleaf pine series are subtotals of the values in the UNDERSTORY data table. The average and maximum shrub heights reported for the pocosin series are based on measurements taken at 10 (5 for the woodland subseries) 10.76-square-foot (43.06-square-foot for the woodland subseries) clipped vegetation plots located in and around the sample area.

For the marshgrass series, all loadings were calculated as the average amount of material present in eight to thirteen 10.76-square-foot clipped vegetation plots located in and around the sample area. The "other" category refers to woody vegetation (MG 04 and 07), litter (MG 02), a surface mat of algal material (MG 01, 02, 04 and 05), or a combination thereof (MG 02 and 04).

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

SAPLINGS AND TREES
For the longleaf pine series, trees were sampled in the entire sample area and saplings (i.e., trees <4 inches in diameter at breast height [d.b.h.])² were sampled in twelve 0.005-acre circular plots (fig. 1). For the pocosin woodland subseries, saplings and trees were sampled in twelve 0.005-acre plots. For the pocosin shrub subseries, saplings and trees were sampled in the entire sample area. Tree measurement data were summarized by d.b.h. size class and by tree status (all, live or dead). Height to crown base 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 values (i.e., live branches and foliage) were calculated from species- and size-specific allometric equations for the longleaf pine series (Taras and Clark 1977, Baldwin and Saucier 1983).

2D.b.h. is measured 4.5 feet above the ground.

UNDERSTORY
For the longleaf pine series, understory vegetation was sampled in 8 to 13 square, clipped vegetation plots (10.76 square feet each) located in and around the sample area. All live and dead vegetation within each square plot was clipped at ground level and returned to the laboratory for oven drying. Pinus palustris cones, litter (L layer) and duff (F and H layers) also were collected in the square clipped vegetation plots. Dead grass material detached from the plant base was collected in the litter category. Understory vegetation and other collected material were ovendried before weighing and determination of area loading.

SHRUBS
For the pocosin series, shrubs were sampled in ten 10.76-square-foot, or five 43.06-square-foot height-stratified clipped vegetation plots in and around the sample area for the shrub and woodland subseries, respectively. All shrubs hanging into the plot was included in the sample, while all understory vegetation that extended beyond the plot boundaries was excluded from the sample regardless of where it was rooted. Vegetation was stratified by 1.6-foot height categories in the field and separated further into live or dead foliage, 0.25 inch, and 0.25-1.0 inch in diameter stem and branch material in the laboratory. Dead foliage consisted primarily of fallen Pinus serotina needles draped on the shrub layer. All vegetation was ovendried before weighing and determination of area loading.

LITTER AND DUFF
For the longleaf pine series, litter and duff were collected in the 10.76-square-foot clipped vegetation plots, ovendried, and weighed to compute the loadings reported in the UNDERSTORY data table. Forest floor material is classified following the scheme outlined in Pritchett (1979), where the litter, or L layer, is comprised of dead, undecomposed vegetation (including dead grass material that was detached from the plant base, and the duff, or a combination of the F and H layers, consists of dead vegetation in various stages of decay. The total number of plots per site ranged from 8 to 13, and is designated by n in the footnote to the UNDERSTORY data table. For the pocosin series, litter was collected in a 5.38-square-foot litter sample plot nested within the larger clipped vegetation plot, oven-dried, and weighed to compute the loadings reported in the LITTER data table. In addition, litter depth was measured at eight random locations within each of the litter sample plots; site-specific litter bulk density values were calculated based on the computed volume (i.e., plot area average depth) and dry weight. Duff was not collected for the pocosin series, as soils in this vegetation type are, by definition, composed of organic material.

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 for the longleaf pine series and pocosin woodland subseries (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 >1 inch in diameter (i.e., 100-hour, and 1000-hour and larger woody fuels) was measured on transects that were 30 feet long (with the exception of LLP 07, where thirty 49.2-foot-long transects were used). The decay class (sound or rotten) and the actual diameter at the point of intersection were measured for all pieces >1 inch in diameter for all sites in the longleaf pine series, and for all pieces >3 inches in diameter for the two pocosin woodland sites (1-3 inch diameter pieces were tallied and were all considered sound). Woody material <1 inch in diameter (i.e., 1-hour and 10-hour woody fuels) was collected in clipped vegetation plots to determine loading. 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.

31-, 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.

SPECIES LIST
Scientific and common species names are from NRCS (1999).

LITERATURE CITED

Baldwin, V.C.; Saucier, J.R. 1983. Aboveground weight and volume of unthinned, planted longleaf pine on West Gulf forest sites. Res. Pap. SO-191. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 25 p.

Brown, James 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, Robert E.; Rothermel, Richard 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.

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

Maxwell, Wayne G.; Ward, Frank 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]. 1999. The PLANTS database. Baton Rouge, LA: U.S. Department of Agriculture, National Plant Data Center. (https://plants.usda.gov/plants).

Pritchett, William L. 1979. Properties and management of forest soils. New York, NY: John Wiley and Sons. 500 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.

Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p.

Taras, Michael A.; Clark III, Alexander. 1977. Aboveground biomass of longleaf pine in a natural sawtimber stand in southern Alabama. Res. Pap. SE-162. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 32 p.