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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Old Growth Ponderosa Pine And Western Larch Stand Structures: Influences Of Pre-1900 Fires And Fire Exclusion, United States Department Of Agriculture, Forest Service
Old Growth Ponderosa Pine And Western Larch Stand Structures: Influences Of Pre-1900 Fires And Fire Exclusion, United States Department Of Agriculture, Forest Service
Forestry
Presents detailed age structure for two western larch stands that historically experienced frequent fires. Compares age structures of eleven ponderosa pine and western larch stands representing a broad range of sites that had frequent fires. Interprets causal factors possibly linked to variations in stand age structures.
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Applying Height Growth And Site Index Curves For Inland Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Methods for estimating both site index and dominant height growth for inland Douglas-fir in the Northern Rocky Mountains are presented and discussed. The methods should be applicable over a wide range of stand conditions because no restrictions were placed on species composition, stand density, spacing, or age structure in the original stem analysis sample. Increased accuracy can be obtained if habitat type is considered, because the shape of the site index curves varied with respect to three major habitat series groupings. Results are summarized in the form of equations, tables, and graphs. Precision curves are used to illustrate the relationship …
Salvage And Thinning Operations In Second-Growth Ponderosa Pine Stands, United States Department Of Agriculture, Forest Service
Salvage And Thinning Operations In Second-Growth Ponderosa Pine Stands, United States Department Of Agriculture, Forest Service
Forestry
This report describes and discusses a harvesting system made up of commercially available equipment and modified farm tractors that has been successfully used to salvage and thin second-growth ponderosa pine stands. Commercial equipment consisted of fellerbunchers, a skidder, and a chipper. Farm tractors were equipped with grapples and metal reinforcings to adapt them to forest use.
A Search For Phytotoxins Influencing Germination And Early Growth Of Ponderosa Pine, United States Department Of Agriculture, Forest Service
A Search For Phytotoxins Influencing Germination And Early Growth Of Ponderosa Pine, United States Department Of Agriculture, Forest Service
Forestry
A series of laboratory and field experiments were conducted to determine if mature ponderosa pines produce a substance (phytotoxin) that inhibits the germination and growth of seedlings directly under the tree crown. Neither live nor dead materials collected from ponderosa pines produced either volatile or water-soluble phytotoxins that drastically inhibited germination of seeds or growth of seedlings. Seed overwintering beneath the canopy of mature pine, or planted in soils collected there, showed reduced germination. Exact cause of the reduction was not determined. If weak phytotoxins were responsible, they did not inhibit growth of seedlings that germinated.
Quaking Aspen - Seed Germination And Early Seedling Growth, United States Department Of Agriculture, Forest Service
Quaking Aspen - Seed Germination And Early Seedling Growth, United States Department Of Agriculture, Forest Service
Forestry
The suckering of aspen (Populus tremuliodes Michx.) as a highly effective means of vegetative propagation is well known and has been widely studied (Baker 1918; Day 1944; Maini 1967; Schier 1974). Less is known about seed propagation, sometimes viewed as having only minor importance because early research (Baker 1918) had indicated that rare seedling establishment was due to low or nonexistent germinability.
Influence Of Some Environmental Factors On Initial Establishment And Growth Of Ponderosa Pine Seedlings, United States Department Of Agriculture, Forest Service
Influence Of Some Environmental Factors On Initial Establishment And Growth Of Ponderosa Pine Seedlings, United States Department Of Agriculture, Forest Service
Forestry
Study plots were established to determine the effects of various environmental factors on ponderosa pine seed germination and initial seedling establishment and growth. A series of soil surface treatments were performed on plots in two locations: within or under the influence of overstory pine trees and in openings away from the pine influence. Seed germination was significantly greater in the opening plots. The overstory canopy and forest floor restricted the amounts of precipitation, light, and heat reaching the soil and probably decreased germination. Cutworms, birds, and small mammals caused the greatest seedling mortality. The largest seedlings occurred in the fire-treated …
Terpenes For Indirect Selection Of Growth Potential In Rocky Mountain Douglas-Fir, United States Department Of Agriculture, Forest Service
Terpenes For Indirect Selection Of Growth Potential In Rocky Mountain Douglas-Fir, United States Department Of Agriculture, Forest Service
Forestry
Possibilities of using terpene composition for indirect selection of growth potential were explored for Rocky Mountain Douglas-fir. Volatile leaf oil analyses were made on 170 5-year-old seedlings that represented full-sib hybrid families, wind-pollinated parental lines of inland origin, and wind-pollinated parental lines of coastal origin. Correlation analyses showed that terpenes could not be used efficiently for indirect selection of growth potential in the inland variety. But, terpenes may be useful in selecting parental lines in programs of intervarietal hybridization.
Regeneration And Early Growth On Strip Clearcuts In Lodgepole Pine/Bitterbrush Habitat Type, United States Department Of Agriculture, Forest Service
Regeneration And Early Growth On Strip Clearcuts In Lodgepole Pine/Bitterbrush Habitat Type, United States Department Of Agriculture, Forest Service
Forestry
Establishment and growth of seedlings 13 years after strip clearcutting was investigated on a lodgepole pine/bitterbrush habitat type in southwestern Montana. Ingress of new seedlings (all from open-coned lodgepole pine) on areas that had been heavily bulldozer scarified was considerably better than on areas without bulldozer scarification. Seed:seedling ratios (established seedlings) ranged from 625:1 to 2,160:1 on scarified sites, and from 1,876:1 to 6,480:1 on unscarified sites. Only 3 years out of 13 resulted in significant numbers of seedlings being established. Advanced regeneration released by logging was growing as rapidly as seedlings established following logging.