Pine forests range from dense tree stands to sparce tree stands. The accessory fuels range from other tree species and shrubs to primarily grasses. The subsections that follow are only a partial list of common pine ecosystems and a fire may include a number of different ecosystems as it grows. The assemblages here are provided as an aid in characterizing the particles generated by the fire.

The most diagnostic single particle generated by pine forest fires anywhere in the world is the bipyramidal tablet of calcium oxalate shown below. These crystals are concentrated in the needles and bark of pine trees and are a very common particle in the plume from a pine forest fire.

Pine/Shrub forest in the Northwest US (Washington, Idaho, Western Montana, Oregon) typically consist of Ponderosa pine (Pinus ponderosa) with some Douglas fir (PseudoTsuga menziesii), Grand fir (Abies grandis), and Tamarac (Larix occidentalis). The shrub layer includes snowberry (Symphoricarpos albus), service berry (Amelanchier alnifolia), wild cherry (Prunus virginiana), ocean spray (Holodiscus discolor), wild rose (Rosa), mallow ninebark (Physocarpus malvaceus), and spiraea (Spiraea). In some areas antelope bush (Purshia tridentata) is a dominant shrub. Grasses are common in the understory.

Pine/Shrub forest in Wyoming and South Dakota includes black hills spruce (Picea glauca), rocky mountain juniper (Juniperus scopulorum), bur oak (Quercus macrocarpa), Quaking aspen (Populus trem, paper birch (Betula papyrifera)

Pine/Shrub forest in the California White fir (Abies concolor), incense cedar, Douglas fir, Black oak (Quercus kelloggii), and western juniper (Juniperus occidentalis)

Pine/Shrub forests in Arizona and New Mexico include White fir, Douglas fir, Quaking aspen, shrub live oak (Quercis turbinella), and Junipers at higher elevations.

Pine/Shrub forests in Utah and Colorado Douglas fir, blue spruce (Picea pungens), and quaking aspen (Populus tremuloides). Shrubs include Gambel oak, mountain mahogany, and sagebrush

Small cubes and square prisms are characteristic of Douglas fir bark and needles.

The common form of calcium oxalate here is druse rosettes in the bark and twigs and diamonds in the dried flower tufts. Both are found in the plume of fires where this is a common shrub.

Shrub Oaks (Blue, Live, Gamble,), Coyote Brush (Baccharis pilularis), Sagebrush, Fairy Duster (Calliandra eriophylla), French Broom (Cytisus monspessulanus), Protea, Lebanon cedar, Manzanita (Arctostaphylos manzanita), Mountain Mahogany (Cerocarpus montanus), Olive Tree (Olea europaea), Lemonade Sumac (Rhus integrifolia), Buckwheats (Eriogonum fasciculatum), Cleveland and black sage (Salvia clevelandii and melifera), Redshanks (Adenostoma sparsifolium), Ceanothus (Ceanothus spp.), Toyon (Heteromeles arbutifolia)

Plains lovegrass (Eragrostis intermedia), Smoke Tree (Dalea spinosa), Verbena (Glandularia spp.), Blue Grama (Bouteloua ), Beggarticks (Bidens spp.), Scrub Oak (Quercus spp.), Deergrass (Muhlenbergia rigens), Shrubby Deervetch (Lotus rigidus),

Artemisia tridentata and tripartita cover large areas of Eastern Washington, Eastern Oregon, Southern Idaho, Eastern Montana, and most of Nevada and Wyoming.