Treesearch

The basic fire spread equations published by Rothermel in 1972 are reformulated in the International System of units.

Contains proceedings of the fourth and last regional workshop sponsored by the National Nongame Bird Steering Committee. The workshop, held in Salt Lake City, Utah, February 11-14, 1980, presented information on management of western forests and grasslands for nongame birds.

Concepts of stream dynamics are demonstrated through discussion of processes and process indicators; theory is included only where helpful to explain concepts. Present knowledge allows only qualitative prediction of stream behavior. However, such predictions show how management actions will affect the stream and its environment.

Questions are often raised concerning the spread of leafy spurge (Euphorbia esula; E. virgata; and their complex) by birds, particularly, since this noxious weed is often found in inaccessible places and beneath lines and other apparent perches. In a study in 1936, Bakke reported no viable seed passed through the digestive tract of mourning doves. However, that does not rule other passerine birds or dissemination by regurgitation when feeding young.

Leafy spurge (Euphorbia esula L.) infests more than 2.25 million acres of agricultural and range lands in the United States and had an economic impact of $10.5 million in 1978 (Noble et al. 1979). The most widespread and heaviest areas of infestation are in the northern and central Great Plains. However, quantitative information and compatible inventory and monitoring procedures for leafy spurge are lacking (Noble et al. 1979).

Discusses studies made from 1967 through 1977 that show seepage from the no longer operating Blackbird Mine in east central Idaho has resulted in acidic waters high in sediment and heavy metals. Suggests high concentrations of cobalt, copper, iron, manganese, lead, and zinc in the Panther Creek drainage are the probable cause of diminished insect and fish populations in the area. Contends that pollution from the mined area will remain a problem in the drainage until rehabilitative measures are taken.

First-season lodgepole pine seedlings only had an average rooting depth of 3.8 inches (9.6 cm), 26 branch roots, and a total root length of 9.8 inches (24.9 cm). Seedlings were field-grown in 1977 on scarified-unshaded seedbeds in the central Rocky Mountains, Colorado.

First year erosion from fill slopes ranged from 5.1 to 9.9 cubic feet per 100 feet of road. Approximately 50 percent of the eroded material was deposited within 20 feet of the toe of fill slope. However, material was transported as far downslope as 437 feet. The placement of filter windows on the fill slopes proved effective in minimizing material leaving the fill slope.

Radioactive phosphorus (P32) was used to measure root depth and lateral spread of tour native plant species which had been subjected to heavy grazing for many years. Compared with root excavation measurements from an earlier study on the same area, rooting depths of all species tested were found to be quite similar by the two methods. Lateral spread differed substantially, however. Roots were found to have a greater lateral spread by the P32 estimate. The isotope method using autoradiography was found to be a sensitive method of determining depth and lateral spread of in situ plant roots...

Dwarf mistletoe [Arceuthobium vaginatum subsp. cryptopodum (Engelm.) Hawksworth and Wiens] distribution and the role of birds as vectors of the parasite were studied in a Colorado ponderosa pine (Pinus ponderosa Laws.) forest. Occurrence of the parasite at distances from a source greater than those attributable to explosive seed discharge was erratic and infrequent. In 24 cases, ages of initial infections in single or multiple tree infection centers were determined. Age analyses indicated that long-distance seed transmission followed by successful infection occurred on an average once...