Treesearch

In 30-year-old, Site IV Douglas-fir in southwest Oregon, fertilizing increased average 4-year basal area growth of dominant trees by 57 and 28 percent on clay loam and sandy loam soils, respectively. Fertilizing with thinning increased growth by 94 and 132 percent over untreated growth. Thinning on clay loam soil increased growth by 53 percent. Treatment did not affect height growth on either soil.

The 1973 Oregon timber harvest of 9.36 billion board feet was 265 million board feet (2.8 percent) below the 1972 harvest. The greater portion of the decrease occurred in eastern Oregon where timber harvest dropped 9.4 percent compared with 0.9 percent in western Oregon.

The need for additional sources of energy and raw material in the forest products industry enhances the opportunity to improve timber utilization by reducing logging residue. This is particularly true on the Pacific Coast where some 14 million tons of logging residue accumulate each year and where some 3 million tons of unused bark create a disposal problem at mills. The need to replace natural gas and oil to generate process steam or for drying with hot gases has given impetus to improved wood and bark combustion to provide needed energy without violating air quality standards. Cylindrical...

A sensitivity analysis of allowable cuts on two BLM master units shows that even-flow allowable cuts depend primarily on: (1) assumed long-term growth potential, (2) period that growth increases must be cumulated before they can be removed from the stands on which they occur, and (3) amount and age-class distribution of the initial inventory. Current allowable cut levels respond relatively more to changes in long-term growth where: (1) the initial inventory is higher, (2) the age classes are more evenly distributed, (3) the growth increases can be cut sooner from the stands on which they...

The effects of logging and associated activities on the habitat of the major forest wildlife species in southeast Alaska are discussed and research results applicable to this region are summarized. Big game, furbearers, and non-game species are considered with respect to their habitat requirements and behavior. Recommendations are made for habitat management with primary concern for wildlife populations. Future needs for wildlife habitat research in southeast Alaska are presented.

Washington's 1973 timber harvest increased 730 million board feet (10.3 percent) above the 1972 harvest to set a record at 7.81 billion board feet. The previous record set in 1929 was 7.38 billion board feet. Nearly all the increase for the State was in western Washington where the harvest was 700 million board feet (11.9 percent) greater than the previous year.

A computer program was written to handle multistage sampling designs in insect populations. It is, however, general enough to be used for any population where the number of stages does not exceed three. The program handles three types of sampling situations, all of which assume equal probability sampling. Option 1 takes estimates of sample variances, costs, and either a specified cost or precision and computes the optimum number of sampling units to select prior to sampling. Option 2 takes the observations, continuous or discrete, from a pilot survey or actual inventory and estimates the...

A number of chemicals of diverse characteristics have arbitrarily been classed together on the basis of their use and given the descriptive name "pesticides." An unfortunate aura of mystery has developed about these chemicals. However, there is nothing unique or mysterious about the chemicals we refer to as "pesticides." Like other chemicals, they have properties which can be accurately measured; they obey all the laws of physics, chemistry, and biology. Chemical and physical properties of a pesticide and interacting environmental factors determine the behavior of pesticides. Behavior in...

The extent of water-dependent log handling and storage facilities in southeast Alaska is summarized, along with the available literature on the environmental impact of these facilities. Field studies were conducted at 16 sites and correlated with laboratory studies of leaching rates and toxicity of the four major wood species harvested in southeast Alaska. Significant effects on water quality are believed to occur only under unique conditions and were observed at only 2 of the 16 study sites. Bark deposits with a high demand for oxygen were observed at all active and abandoned log dumping...

The evaluation of timber access road alternatives is one of the primary tasks in timber harvest planning and design. During the planning stages, it is also one of the most difficult to accomplish quantitatively because a basis for comparison is related to such values as grade, length, horizontal and vertical curvature, and volumes of excavation and embankment. Within reasonable time constraints, these values are almost impossible to produce with any accuracy. Evaluating several alternatives is usually out of the question.The analysis of timber access road alternatives involves four...