Treesearch

The United States has abundant supplies of fresh water. The renewable water supply of the coterminous United States amounts to about 1,400 billion gallons per day (bgd). Aggregate daily withdrawals amount to 343 bgd or 25% of renewable supply. Aggregate daily consumption amounts to 93 bgd or 7% of renewable supply.The Nation's watersheds are generally in good condition. But special attention must be given to managing the soil and vegetation on more than 70% of our watersheds to maintain or improve the quality and quantity of water flowing from them. A survey of watersheds in the U.S....

Range vegetation is defined as grasses, grass-like plants, forbs, and shrubs. When the plant community is dominated by this type of vegetation, the land is referred to as rangeland. Rangelands predominate in the western United States as natural grasslands, shrublands, savannas, deserts, tundra, alpine, coastal marshes, and wet meadows. In the eastern United States, rangelands occur as tallgrass prairie, marshes, or wet meadows. Riparian ecosystems and plant communities dominated by introduced species are also considered rangeland. About 34% or 770 million acres of the total land base in...

In 1987, 1.5 billion acres, about 63% of the total land and inland water area of the United States, was in forest and rangeland. Forest totals 32% and rangeland totals 34% of the land area. Most of the Nation's forest and rangeland are in nonfederal ownership.In 1987, about 1 billion acres or 67% of the total were owned by nonfederal public agencies, forest industry, farmers and ranchers, and other private individuals. The nonfederal forest lands are concentrated in the East, and private rangelands are concentrated in the West. The federal lands are administered primarily by two agencies -...

Minerals are essential to modern life. They are important to the national economy, and to the economy of many individual states. Some minerals are of strategic importance, and essential to national economic and military security.Minerals are different from other forest and rangeland resources covered in the RPA Assessment. They are nonrenewable, and are more difficult to find, inventory, and develop. Mineral development is governed by a complex set of laws, and administered by a number of federal agencies.The U.S. is rich in many of the minerals it requires, but there is uncertainty about...

These proceedings consist of 43 presented papers on control of damage caused by many different animals. After an "overview" session, papers were presented in sessions titled: Carnivores, Urban, Big Game, Birds, and Rodents and Lagomorphs.

Fifteen species of prey were utilized by nesting Prairie Falcons (Falco mexicanus) as determined through pellet analysis. Thirteen-lined Ground Squirrels (Spermophilus tridecemlineatus), the most common prey, were present in 91% of the pellets, followed by Western Meadowlarks (Sturnella neglecta) which were present in 56% of pellets. Horned Larks (Eremophila alpestris) and Lark Buntings (Calamospiza melanocorys) were found in 23% and 12% of the pellets, respectively. Additional prey species were present in low frequencies (≤55%). Eighty-nine percent of pellets contained both bird and...

Under-story-overstory relationships were examined over 7 different growing stock levels(GSLs) of 2 size classes(saplings,8-10 cm d.b.h. and poles, 15-18 cm d.b.h.) of ponderosa pine (Pinus ponderosa) in the Black Hills, South Dakota. Generally, production of graminoids, forbs, and shrubs was similar between sapling and pole stands. Trends among GSLs were also similar between these tree size classes. Graminoids and forbs were most abundant in clearcuts and the 5 m2/ha basal area. Intermediate amounts were produced at GSLs of 14-23 m2/ha and lowest in unthinned stands which had basal areas...

Thinning lodgepole pine stands increased light intensity, wind movement, insolation, and temperature. Temperatures on the south exposure of tree trunks and of soil were significantly higher in thinned than unthinned stands. Light and wind also were higher in the thinned stand. Fewer mountain pine beetles were caught in pheromone-baited traps in a thinned than in an adjacent unthinned stand. Percentage of trees killed by mountain pine beetle was only 2 percent in a thinned stand compared to 16 percent in an adjacent unthinned stand.

A knowledge acquisition program was written to aid in obtaining knowledge from the experts concerning endemic populations of mountain pine beetle in lodgepole pine forest. An application expert system is then automatically generated by the knowledge acquisition program that contains the codified base of expert knowledge. Data can then be entered into the expert system to generate predictions.

Surveys in southeast Alaska in 1984 and 1985 were the basis for estimating net willingness to pay of hunters. Net willingness to pay was highest for resident deer hunters ($331) and lowest for nonresident moose hunters ($55). Relationship between willingness to pay and expenditures is discussed.