Search by keywords, or use filters to narrow down results by type, topic, or ecosystem.
Displaying 5841 - 5860 of 6068 results
The fire cycle in low-elevation mesic coniferous forests of the Bitterroot Canyons, Montana, has changed from about 60 years before European settlement to about 7500 years between 1910 and 1980. The decreased fire frequency may be responsible for…
Year Published:
Globe huckleberry (Vaccinium globulare) fruit is a major food source for the grizzly bear (Ursus arctos horribilis) in northwestern Montana. A ranked-set sampling pattern was used to determine the effects of wildfires, timber harvest practices, and…
Year Published:
The history and influence of tires was studied at the forest- grassland ecotone in high valleys ofsouthwestern Montana. Inves- tigations were focused upon several sites having early landscape photographs and modern retakes that allow for detection…
Year Published:
Provides information on fire as an ecological factor for forest habitat types occurring east of the Continental Divide in Montana. Identifies "Fire Groups" of habitat types based on fire's role in forest succession. Describes forest…
Year Published:
Vegetation was sampled on 330 sites known to be used by grizzly bears (Ursus arctos). The response to disturbance of 6 shrub species important as grizzly bear foods was determined by comparing their percent canopy cover on disturbed sites with that…
Year Published:
Interprets changes in forest and range vegetation resulting from the absence of fire. Eighty-six matched photographs covering the period 1871-1982 provide the basis for describing how vegetation has changed in various plant communities. These scenes…
Year Published:
The study quantified differences between fire-retarding abilities of monoammonium phosphate samples from five different sources. Ponderosa pine needles and aspen excelsior fuel beds were spray-treated with different levels of chemical solutions,…
Year Published:
The authors examine variation in the length of mean intervals between fires (occurring between the years 1600 and 1910) in sample units of various sizes, ranging from a point on the ground (single tree) to a large stand (200 to 800 acres; 80 to 320…
Year Published:
Relationships between height of big sagebrush and crown area, fuel loading, bulk density, size distribution of foliage and stemwood, and fraction dead stemwood are presented. Based upon these relationships, modeled rate-of-fire spread and fireline…
Year Published:
Whitebark pine (Pinus albicaulis) is known to have its seeds harvested and cached in the soil by Clark's Nutcracker (Nucifraga columbiana), and unretrieved seeds are known to be capable of germinating and establishing new pines. Many other…
Year Published:
Abstract
(1) Clark's nutcrackers (Nucifraga columbiana) store a mean of only 3.7 whitebark pine (Pinus albicaulis) seeds per cache, which reduces competition for moisture and space. The mean depth at which seeds are stored, 2.0 cm, is compatible…
Year Published:
A comparison of the trichopteran communities of streams associated with aspen, spruce—fir, and mixed—conifer forests demonstrated significant differences in structure. Though tricophteran species composition in aspen—associated and spruce—fir…
Year Published:
The importance of fire as an ecological disturbance in the Northern Rockies is well accepted. Lightning is generally thought to have been the main source of ignition prior to settlement by Europeans. But writings of explorers and pioneers mention…
Year Published:
Perceptions of risk and danger are largely based on what society and organizations choose to value and what they choose to fear. Often, these values are shaped by larger organizational and political interests that bias perceptions of risk, danger,…
Year Published:
This article addresses how organizations deal with adversity and how organizations adapt within adverse conditions. The authors comment that most research emphasizes “organizational and not individual or group responses to adversity,” and those…
Year Published:
Fire, geomorphic processes, and landforms interact to determine natural patterns of ecosystems over landscapes. Fire alters vegetation and soil properties which change soil and sediment movement through watersheds. Landforms affect fire behavior and…
Year Published:
Logging slash on 73 clearcuts was broadcast burned over a wide range of conditions, achieving a broad array of fire intensities and effects. An intense wildfire was also evaluated. Fire effectiveness was measured and related to preburn conditions…
Year Published:
Four series of color photographs show different levels of downed woody material resulting from natural processes in four forest cover types in Montana. Each photo is supplemented by fuel inventory data and potential fire behavior ratings.
Year Published:
The objective of this paper is to provide a comprehensive review of literature on the vegetation of the sage brush region of North America. Despite its prime importance as a grazing resource, and the problems produced by its use and misuse, research…
Year Published:
Two series of color photographs show different levels of downed woody material resulting from natural processes in two forest cover types in Montana. Each photo is supplemented by fuel inventory data and potential fire· behavior ratings.
Year Published: