Treesearch

Subjects valued environmental goods using a response mode expressing willingness to pay as a multiplier or divider of a purported "budgetary unit." Hypothetical willingness to pay was found to be highly dependent on the size of the budgetary unit. Rejecting two other interpretations, we believe the results suggest that people's contingent values are only vaguely represented in monetary terms; any dollar amount within a broad range is considered an acceptable expression of value. Although the procedures differ from those of a typical contingent valuation suruey, the results demonstrate some...

In contrast with the days of the early explorers, when wilderness travel in America was predominantly a solitary activity, the wilderness resource is now shared among many interests. Interaction among these various interests leads to varied amounts of conflict. Studies in the United States, conducted in multiple National Wilderness Preservation System units, across geographic regions and across agencies, closely examine the role of behavioral and attitudinal contributors to conflict between hikers and recreational packstock users as a case study conflict situation. A survey of previous...

Most of this book focuses on direct impacts to wildlife that result from contact with people. The purpose of our chapter is to provide a broad overview of the indirect influences that recreation has on wildlife. Recreational activities can change the habitat of an animal. This, in turn, affects the behavior, survival, reproduction, and distribution of individuals. Although more difficult to isolate and study, these indirect impacts may be as serious and long-lasting as direct impacts for many species.

Stand density of even-aged stands of ponderosa pine in California seems to be ruled by Dendroctonus bark beetles, rather than the suppressioninduced mortality common for other tree species. Size-density trajectories were plotted for 155 permanent plots in both plantations and natural stands. Bark beetle kills created a limiting Stand Density Index of 365 which differed little between stands on poor sites east and good sites west of the crest of the Sierra Nevada and Cascade Range. Although good sites would be expected to carry a greater stand density than would poor sites, more explosive...

Understanding the functions and processes of ecosystems is critical before implementing forest ecosystem health projects on the landscape. Silvicultural treatments such as thinning, prescribed fire, and reforestation can simulate disturbance regimes and landscape patterns that have regulated forest ecosystems for centuries. As land managers we need to understand these processes, including historical disturbance regimes and then determine where on the landscape the forests are at high risk to uncharacteristic disturbances. By using our knowledge of ecosystem processes we are developing site...

White pine was once a very important part of the ecosysystem in the northern lake states. Turn of the century logging and wildfires removed white pine from many of the ecosystems of which it was an integral part. Early reforestation efforts were largely unsuccessful. The native white pine weevil and the exotic white pine blister rust made white pine establishment difficult at best. Both of these pests pose management challenges. However silvicultural practices can give white pine a distinct advantage over the pests. These practices include regenerating white pine under the shelter of...

Overstocked 70- to 90-year-old stands of ponderosa pine on medium to low quality sites were thinned in 1980 to 40, 55, and 70 percent of normal basal area and compareh to an unthinned control. Mortality was recorded annually. Growth was measured every 5 years from 1980 to 1994. After 15 years, mortality, primarily from bark beetles and annosus root disease, was reduced by 100, 96, and 92 percent relative to increasing amounts of reserve basal area. Thinned stands averaged six times more cubic-foot growth than unthinned stands. More growth and less mortality could result from treating...

This paper presents the result of the first dasometric analysis made with the data of some permanent thinning plots established at different times since 1964 in the Unit of Conservation and Forest Development #2 in Chihuahua State, Mexico. The results show the benefits of thinnings on the growth rates of residual stands, the increment's redistribution, and the potential mortality.

As requested by the Applegate Partnership, the Medford District Bureau of Land Management, the Rogue River and Siskiyou National Forests, a team of six specialists (Dr. Tom Atzet, USFS ecologist; Dr. Mike Amaranthus, PNW soil scientist, Dr. Don Goheen, USFS pathologist and entomologist, Tom Sensenig, BLM silviculturist, Dr. Dave Perry, Oregon State University conservation biologist and Dr. Kevin Preister, Rogue Institute of Ecology and Economy, social anthropologist, Sue Rolle and Dr. Diane White coordinated the effort and edited the manuscript respectively) were given two weeks to assess...

Over 360 exotic forest insects and about 20 exotic diseases have become established in the U.S. Many of these organisms have become serious pests, causing great economic impacts and irreversible ecological harm. Despite efforts to exclude exotic species, forest insects and disease organisms continue to be introduced at a rather rapid rate. In the last few years, one disease organism and six forest insects have been introduced or discovered in the U.S. Some of these organisms have the potential to become serious pests. Preventing introductions of exotic organisms is a global problem that...