Thesis (M.S.)--Oregon State University, 1987. / Typescript (photocopy). Includes bibliographical references (leaves 74-77). Also available on the World Wide Web.

Thinning is rapidly gaining importance in the Pacific Northwest as old-growth timber reserves approach exhaustion. In the past, thinnings have been extracted by wheeled or tracked machines, but the need for reducing soil disturbance, while operating in any kind of terrain, has led to the development of a number of skyline systems. Two of these systems were studied, a Washington Model 98 Skylok yarder rigged with a running skyline, and a West Coast Tower using a standing skyline. Both systems are described in detail. A time study was done on seven skyline "roads" for the West Coast Tower, and on two "roads" for the Washington Model 98. The construction of a computer simulation model of the yarding process is described. The various elements of the logging process were modelled in several ways, and the thesis shows how the model could be used to make guidelines for planning logging layouts, for sensitivity analyses, for cost and time prediction, for methods improvement, to assist in equipment selection, to help allocate machines, and to show the applicability of skyline thinning to an area outside of the Pacific Northwest. External yarding distance, over a wide range, was found to be unimportant in determining yarding costs. Stocking was an important factor. It was shown that there was an optimum road width for a given length and shape of skyline "road". Potential savings were shown in loading and yarding procedures. The standing skyline was found to have no advantage in deflection, and it was more expensive to set up than the running skyline. Improvements in tree marking procedure are suggested. Loading was found to have considerable potential for cost reduction. Suggestions are made for future research, and the lack of some very basic knowledge is noted. There is abundant room for, and a great need of, an extension of this analysis. / Forestry, Faculty of / Graduate

Forest sampling is conducted to determine current conditions and trends of change. When current conditions are estimated, most of the commonly used sampling designs specify the spatial distribution of sample units. When estimation of change is desired, several schemes may be employed. Some are combined with current condition inventories; some are independent. The former are relatively imprecise; the latter relatively expensive. A system of temporal distribution of sample units, sampling on successive occasions with partial replacement of sample units, has been developed for simultaneous estimation of current conditions and trends. As the emphasis is on time, rather than area, this system operates with conventional sampling designs to increase their efficiency. This study investigated the theory of sampling with partial replacement to establish the validity of the claims of increased efficiency in comparison with conventional systems. Three cases are examined, through example, for estimation of mean volume per acre and growth in volume per acre. Sample sizes and costs are developed for the situation of simple random sampling of both finite and infinite populations. The comparisons are favorable to the proposed system. The possibilities of using this system with two recent developments in cruising techniques are explored. Finally, the applicability of this system to British Columbia forest surveys is examined. A case is made for transition of the existing provincial system to sampling with partial replacement. / Forestry, Faculty of / Graduate

The selection of optimum road surfacing for logging roads is studied. A dynamic program model that simulates different road surfaces, over the length of the road, is developed to arrive at the optimum combination of road surfaces. The model simulates the travel, of up to three different vehicle types over the road. The physical characteristics of the road, the road surface and the vehicles are used to determine travel speeds. Travel speed and vehicle operating costs are used to find vehicle costs relative to the road surface. These costs are combined with surface construction and maintenance costs to find the optimum combination of surfaces. Testing of the model revealed that volume of wood was of less importance than road gradient in the determination of the optimum combination of road surfaces. / Forestry, Faculty of / Graduate

Northern hardwood forests are a vast, temperate forest-type existing across much of northeastern North America. In the northeastern U.S., these forests are found from New York to Maine where they have central cultural, ecological, and economic significance. These ecosystems are incredibly variable across this region, growing on a range of sites and influenced by a suite of biotic and abiotic conditions. Developing management regimes that accommodate the ecological complexity of these forests has been the focus of silvicultural studies for decades; however, this work has been constrained by temporal and spatial limitations. As such, there is still uncertainty regarding the evolution and variability of northern hardwood forests over time and across sites under different management scenarios. To address this uncertainty we synthesized long-term silvicultural studies (20 years +) throughout the northeast and assessed outcomes as they related to management objectives and changing forest conditions. Specifically, we explored the regeneration dynamics and development of overstory conditions for even and uneven-aged systems with four distinct approaches. First, we established context for this work through review of existing silvicultural research and analysis of the current northern hardwood resource. Next, we applied long-term, regional inventories to consider abiotic and biotic factors influencing recent sugar maple (Acer saccharum) establishment and survival. We then evaluated long-term outcomes of commonly applied even and uneven-age silvicultural systems across a range of sites in New York and New Hampshire using repeated inventories from long-term research trials. Finally, we followed the evolution of gap dynamics over eight decades in the oldest group selection study in North America; research established at the Bartlett Experimental Forest in New Hampshire in the early 1930s. Cumulatively, results showed a frequent disconnect between structure and composition of the overstory and regeneration layers, and the potential for future challenges to sustaining current overstory species. In addition, this work highlighted the pervasive, negative influence of American beech (Fagus grandifolia) across the region on regeneration of desired species, namely sugar maple and yellow birch (Betula alleghenesis). Outcomes from this work suggest that a variety of silvicultural systems can be used to maintain and regenerate northern hardwood forests; however favorable outcomes require careful consideration of site conditions with management regimes tailored accordingly.

The characteristics of tourists visiting Utah that are pertinent to defining target markets for the direction of state promotion programs were studied and analyzed during the summer of 1966. Five significant geographical-party composition target markets were identified as prospective tourist markets . These were California families, East-Wes t North Central families, Western families, East- West North Central couples, and California couples. Target markets of enroute tourist parties were also identified for instate promotional efforts. The markets identified were divided on their relative degree of vacation planning and willingness to deviate from a planned route to visit additional attractions. Significant differences among parties found in different regions of the State were identified. Some of the differential variables studied were education, income, occupation, and tourist party vacation area suggesters and decision makers.

Soil moisture depletion was studied in quaking aspen and Gambel oak areas of central Utah. The study area is located at about 8100 feet elevation in a zone with 20 to 25 inches precipitation annually. Treatments ranged from no disturbance to clearcutting. Soil Moisture was measured periodically during the summer of 1966. Results showed less soil moisture depletion on the plots of least residual basel area. Average soil moisture depletion the season following cutting at two sites was 4.3 inches less than it was on higher residual basal area plots. The reduction in soil moisture depletion occurred principally below the roots of the herbaceous plants and grass in the zone that would normally be occupied by living tree roots.

Two of the biggest concerns facing communities in the Intermountain West are the dichotomies of rapid growth and development as opposed to economic decline and stagnation. Numerous strategies have been developed by social and economic scientists to help communities manage the many problems associated with these concerns. One strategy recommended by many researchers and used by numerous communities to stabilize their economies is economic diversification. For many rural communities in Utah, tourism and recreation have been used as part of that diversification effort. Recreation and tourism also play a role in the dichotomies of rapid growth and development by often serving as the antecedent to rapid growth, or serving as the antidote for economic stagnation and decline. This thesis examined four rural communities in Utah which have diversified or are attempting to diversify their economies through incorporating tourism and recreation into their economies, which also include agriculture, ranching, and extraction of natural resources, as well as other industries such as manufacturing and services. Our purpose was to examine strategies used by these communities to make recreation and tourism compatible with other activities, as well as determining what tactics they drew upon to preserve the small town atmosphere and unique characteristics of their communities. Through understanding and sharing the problems encountered and strategies used by these four communities, we hoped to assist other communities attempting to integrate tourism and recreation into their economies and lifestyles.

There is limited information on how young-growth giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz)/mixed conifer stands respond to forest management strategies. An applied research study was initiated in 1989 when 35 approximately 0.1 acre (0.04 hectare) plots were installed in six young-growth giant sequoia/mixed conifer stands. The objective of this study was to determine if there was a difference after 20 years between treatments (a) thin only, (b) thin and prescribe burn, and (c) control in terms of the effect on overstory growth and yield, understory plants, tree regeneration and downed woody debris. Analysis of variance (ANOVA) for cubic-foot growth over 20 years showed significant difference (p = 0.016) between the three treatments. Three diversity indices (richness, evenness, and heterogeneity) showed varied results with environmental factors of slope and elevation major variables affecting plant diversity. Regeneration study showed significant seedlings per acre difference (p = 0.010) between treatment (b) and treatments (a) and (c) with white fir (Abies concolor [Gord. & Glend.] Lindl. ex Hildebr.) the majority at 87%. These collected and analyzed data will benefit Mountain Home Demonstration State Forest along with other forest managers who actively manage giant sequoia stands, whether natural or plantation.

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