The major objectives of this study were to: 1. evaluate the financial aspects of improvement thinnings for fuelwood in Appalachian hardwood stands. 2. determine direct net energy values from energy inputs and outputs for fuelwood harvesting in Appalachian hardwoods. The landowners decision on whether or not to thin was greatly influenced by haul distance and his opportunity cost for time spent harvesting wood. Other considerations included the market price for both firewood and firewood stumpage. Two cases were analyzed using discounted cash flows, the first considered the landowner as a firewood consumer. The results of this portion indicated that at low haul distances (< 15 miles) and low opportunity costs ($0 to 5 per hour), the landowner should produce his own firewood. At longer haul distances an open market purchase should be made and at higher opportunity costs a contractor should be hired to harvest the firewood. In the second case, the landowner acted as a firewood producer. The results indicate that at low haul distances and low opportunity costs of harvesting, the landowner can attain reasonable rates of return on the investment (approximately 4% after-tax in real terms). At greater haul distances and higher opportunity costs the investment returns diminish. The second objective concerning energy resulted in favoring larger scale operations at longer haul distances and smaller operations at shorter distances. The major influences on energy values were haul distance and degree of mechanization. Overall, this analysis presents a process for evaluating firewood thinnings and offers the landowner the capability of examining a variety of sites and harvest systems. However, the results should be viewed only as an example situation. / Master of Science

Thinning from above and below were compared using an economic optimizing dynamic program, FORTE (Arthaud 1986). Economically optimal (net present value maximizing) thinning regime and rotation age were determined for benchmark economic and model inputs. Sensitivity of net present value and optimal management regime were tested for varying interest rates (6 or 8%), site indexes (50, 60 and 70, base 25 years), fixed and variable thinning costs, planting density (440, 680 and 910 trees per acre), stumpage prices and thinning type. Given the same assumptions, thinning from below consistently provided the higher net present value for the optimal regime than thinning from above. For the benchmark assumptions, both thinning types had two thinnings in their optimal regimes. Optimal rotation age and thinning timings occur later when thinning from above. Both thinning types provided higher net present values than not thinning under all conditions except pulpwood management. / Master of Science

Several nonlinear, individual tree crown height increment equations were tested for their ability to predict annual crown height increment in loblolly pine plantations. The selected model contained tree height (HT), tree crown ratio (CR) raised to the one-half power, age (A), and a competition index (CI) for the distance-dependent model and the ratio of quadratic mean diameter to tree dbh (DR) for the distance-independent model. The distance-dependent and the distance-independent models were the same form, except for the expression for competition. Hypothesis tests revealed that thinning, both its intensity and the elapsed time since its occurrence, had a significant effect on crown height increment. A thinning variable, THIN1, which accounted for thinning intensity and the interval since thinning, was developed and incorporated into the final individual tree increment models. Predictions of crown height increment were improved using models with the THIN1 variable as compared to those with no thinning allowance. In another approach, existing crown height equation was modified to account for the effect of thinning on crown recession. Another thinning variable, THIN2, similar to THIN1, was added to the crown height model. This model yielded better results than its counterpart with no thinning variable; however, the improvement was not as great as for the increment models. The individual tree increment models were also used to form a stand level crown height increment model. The independent variables were collapsed to stand-level statistics; the final model contained average height of dominants and codominants (HD), average crown ratio (R), age (A), and the THIN1 variable. Unlike the individual tree models, raising the average crown ratio to .5 did not improve the fit; however, including THIN1 did improve the results. From this study it was concluded that better data, a standard definition of height to the live crown, and other crown variables, such as crown diameter, will be required to produce more refined individual tree crown height increment models. / Master of Science

Thesis (M.S.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Sept. 4, 2002). Thesis advisor: David S. Buckley. Document formatted into pages (xi, 112 p.). Vita. Includes bibliographical references (p. 104-111).

Thesis (M.S.)--Mississippi State University. Department of Forestry. / Title from title screen. Includes bibliographical references.

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 1996. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 2001. / Document électronique également accessible en format PDF. CaQCU

Thèse (M.Ress.Renouv..) -- Université du Québec à Chicoutimi, 2006. / Bibliogr.: f. 40-52. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 179-190).

Research in optimizing forest management has focused on single-stand problems to derive optimal harvest sequences in terms of residual basal area or residual stand structure for uneven-aged stands, and timing of pre-defined thinning treatments and clearcut harvests for even-aged stands. Recent research results provide various means of numerically deriving optimal management prescriptions for single-stand problems, thus considering all feasible solutions as opposed to considering only pre-defined harvest alternatives. However, forest-level problems involving aggregates of stands with similar management constraints are usually solved by evaluating pre-defined harvest sequences. Forest-level management optimization problems in which individual stands may be assigned to either even-aged or uneven-aged silvicultural systems have not been modelled. A dynamic forest management model is describer: that prescribes silvicultural treatments for stands within a multi-stand management unit. Results of an application of this approach to an Appalachian hardwood forest, comparisons of individual stand and whole forest optimal solutions, and efficiency of the solution algorithm are discussed. / Ph. D.