Archive image from page 41 of A descriptive analysis of Montana's. A descriptive analysis of Montana's forest resources descriptiveanaly11schw Year: 1975 seeds; (2) thick, fire-resistant bark that permits trees such as western larch to survive fires long enough to cast their seed on the burned area; and (3) light, wind-disseminated seed of western larch and Engelmann spruce that can blow considerable distances. The important timber species in Montana most favored by fire are western larch and lodgepole pine. On particular sites (where they are serai), fire also favors ponderosa pine, Douglas-
Archive image from page 41 of A descriptive analysis of Montana's. A descriptive analysis of Montana's forest resources descriptiveanaly11schw Year: 1975 seeds; (2) thick, fire-resistant bark that permits trees such as western larch to survive fires long enough to cast their seed on the burned area; and (3) light, wind-disseminated seed of western larch and Engelmann spruce that can blow considerable distances. The important timber species in Montana most favored by fire are western larch and lodgepole pine. On particular sites (where they are serai), fire also favors ponderosa pine, Douglas-fir, grand fir, and Engelmann spruce. Generally, these species do best when their seedbeds are free from competition and the duff has been burned away to expose a mineral soil seedbed. Controlled fires are used in combination with appropriate harvesting systems to create such conditions. By and large, even intense fires do little physical or biological damage to the soil itself. For several years following fire, release of nutrients is accelerated, populations of beneficial bacteria and actinomycetes increase, and harmful fungal populations decrease--all changes that benefit timber production. Under severe conditions, burning of the forest floor vegetation may lead to increased, short-term overland water flows and soil erosion. Generally, fires benefit wildlife. For a number of years after burning, forbs, grasses, and shrubs thrive; food and cover are abundant until the trees once again occupy the site (fig. 17). Wildfires still have an important role to play in perpetuating the fire- adapted ecosystems now present. To this end, the Forest Service has established a 'let-burn' area on the Bitterroot National Forest to gather data on the impacts of fire. FOREST SUCCESSION FOLLOWING FIRE o 25 50 75 YEARS SINCE BURN 100 Figure 17.—Forest succession following fire. 30
Size: 1775px × 1127px
Photo credit: © Actep Burstov / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archival, archive, art, artwork, book, classic, classical, drawing, historic, historical, history, illustrated, illustration, image, page, picture, print, reference, text, vintage
