Thesis (M.F.)--Oregon State University, 1977. / Includes bibliographical references (p. 40-43). Also available on the World Wide Web.

This thesis provides a methodology for examining forest harvesting operations through simulation. The model is capable of simulating multiple landing, single dump logging configurations. Facility locations, equipment types and numbers, parameters, and functional relationships may be varied so that a wide range of west coast British Columbia logging operations can be represented. The model was written in General Purpose Simulation System V (GPSSV) language. A substantial saving in development cost is realized over a FORTRAN-based simulation. The model allows independent users to make modifications within the program in order to adapt to the particular operating rules and policies of their operations. Model formulation for this thesis is based on an actual west coast logging division. Verification of the model involves a three-stage approach. First, a set of hypotheses and postulates are constructed for the subsystems of the harvesting operation and, secondly, these are empirically tested. Historical data is compared to simulation results in order to confirm that particular subsystems adequately model the real system. Tactical considerations and experimental design regarding model execution are presented. It is shown that antithetic variates can be effectively used to reduce the variance of the mean of a response. An improved truck dispatching routine is developed with the objective of maximizing productivity, subject to the availability of yarding and trucking resources. This policy balances the objectives of minimizing truck travel time, truck delays at landings, and yarding stoppages due to timber "saturated" landings. In comparison with other dispatching policies, productivity can be increased from two to over ten percent. The dispatching algorithm has been programmed for a Hewlett-Packard 9830A desktop computing system. The dispatcher, utilizing radio communications with all of the landings and trucks, can theoretically be supplied with the optimum landing to which a truck should be dispatched. Some other practical applications of the timber harvesting simulation model are discussed. Flexibility in the model, in parameter initialization and the substitution of new relationships, allows the investigation of many features of forest resource planning and machine allocation and scheduling. The determination of equipment requirements for various configurations, the evaluation of new equipment and the comparison of different operating policies can be undertaken with the model. Another benefit derived from the development of the model is an increased understanding of the timber harvesting system which allows the design of better operating policies and greater control within the system. / Forestry, Faculty of / Graduate

Diss. Luleå : Luleå tekniska univ., 2004.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.

Many onshore windfarms in Scotland are being built on peatlands. As a consequence, the impacts of development activities on the peatland and downstream environments are an important emerging issue. For example, a reduction of the quantity of carbon (C) stored in the peatland and increased phosphorus (P) and nitrogen (N) concentrations in streams may cause changes in the peatland carbon sink strength and aquatic carbon emissions, and exceedance of EU Water Framework Directive (WFD) P threshold values, respectively. To further assess the impacts from peatland-based windfarm development, the following four research questions were posed: 1. Which specific development activities have the greatest impact on concentrations of C, N and P in streams? How long does it take for C, N and P concentrations to return to baseline conditions? 2. Which specific windfarm development activities caused the greatest aquatic export of carbon and nutrients? 3. What are the controls on concentration and export of aquatic C, N and P in streams draining peatland developments? 4. How effective are site-derived adsorbent materials and an iron ochre at preventing phosphorus from entering upland streams on peatland? Presented in this thesis, are the results from 3-weekly spatial streamwater sampling of 18 sub-catchments (ranging 0.03 - 12 km2) – from October 2011 to March 2013 – which covers the majority of the peatland-based development and one year beyond, of the Whitelee windfarm Phase 2 extension 16 km south of Glasgow, Scotland. Dissolved and particulate organic carbon (DOC/POC), soluble reactive phosphorus (SRP) and total oxidised nitrogen (TON) concentrations were measured and exports were calculated from stream gauging. The spatial catchment controls on stream water chemistry were investigated through a multiple linear regression analysis. Fraction of sub-catchment area that was subject to forest felling was found to be significantly positively correlated with concentrations and exports of DOC, POC, SRP and TON; with TON specifically by felling that had occurred more than one year previously. Density of tracks / cable trenches / turbines, and fraction non-forested area in general exerted a negative control on exports. Evidence of SRP attenuation processes in addition to dilution were found in some streams. While neither river sediment nor track or cable trench gravels were very effective at removing SRP, from the results of batch adsorption experiments, a sample of mineral subsoil was. SRP was attenuated in areas where there was a greater proportion of peaty gleys, in the riparian zone along the main stream, and the outcome of the batch adsorption experiments points to attenuation of SRP onto mineral subsoils, where present. Comparing long-term (seven year) time series of the original Whitelee windfarm directly north of the site, with the extension site (this study) it was possible to estimate the time required for recovery to pre-development concentrations. Mean annual [DOC] increased to 31.4 mg l-1 during development of the extension site. While it took five years for the DOC to recover at the original site, in the year following development at the extension site, mean annual [DOC] was still above the baseline. Mean annual [POC] increased to a maximum of 2.6 mg l-1 during development of the extension site, and as with the original site it returned to the baseline the year following development. The mean annual [SRP] increased to a maximum of 50.5 μg l-1 during development, leading to a reduction in water quality from ‘good’ to ‘moderate’ based on comparison with Environmental Quality Standards (EQS). It took four years for the SRP to recover at the original site, and mean annual [SRP] was still above baseline at the extension site in the year following development. The streamwater C, N and P has not been measured as close to, and for such a range of, windfarm development activities. This research has demonstrated links between windfarm development, forest felling in particular, and increased concentrations and exports of DOC, POC, SRP and TON in streams. While the increases were localised within the site itself, investigation of attenuation processes point to peaty gley soils along the main stream, and tracks, cable trenches and turbines – and their associated settling lagoons and silt fences – as potentially mitigating the increased dissolved carbon and nutrients. Outcomes of this research are suggested improvements to the guidance for developing peatlands, especially with regards to monitoring streamwater carbon for a sufficient period post-development, and for the removal of brash on peat soils. Further research could investigate the use of adsorption materials to mitigate phosphorus mobilisation from brash sources to streams, over a time scale of at least two years at the field scale. Laboratory-based environmental fate studies of the increased streamwater carbon could investigate the rates of CO2 efflux with time and with varying concentrations of nutrients, which would help to improve the Scottish Government's carbon calculator estimates of carbon loss from peatland-based windfarm development.

95% of the productive forest land in Sweden are now being exploited for forestry. The new Forestry Act of 1993 equate the goal of production and the environmental goal which means that the objective for forestry is a sustainable yield, while the biological diversity must be preserved. Recent years results from the inventories of the Board of Forestry show declining trends in how nature conservation aspects taken into consideration at the felling sites.The aim of this study is to investigate what happends with the nature consideration taken at felling sites in the long run. 20 final fellings in the county of Östergötland were re-inventoried 7-9 years after final felling. These felling sites had previously been inventoried before final felling (P0) and one year after final felling (P1) in the inventory Polytax by the Board of Forestry. On 18 of 20 felling sites nature consideration had decreased significantly from P1 inventory to re-inventory. Retention trees had declined the most, 7.9% of the total volume of retention trees was gone. Taking conservation in to consideration at final felling sites by retenetion of trees and habitats with high conservation value is an important step in preserving biodiversity and increasing the chances of survival for the species considered sensitive to forestry. In order to improve the consideration of nature and thereby increase the chances of species survival a functional follow-up of conservation efforts at the felling sites is required.

Diss. (sammanfattning). Umeå : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 1999. / Document électronique également accessible en format PDF. CaQCU

12 pp. / Pine Bark Beetles, THE PIÑON IPS BARK BEETLE, FIREWOOD AND BARK BEETLES IN THE SOUTHWEST, USING INSECTICIDES TO PREVENT BARK BEETLE ATTACKS ON CONIFERS, GUIDELINES FOR THINNING PONDEROSA PINE FOR IMPROVED FOREST HEALTH AND FIRE PREVENTION / Various techniques to reduce brood production of Ips and Dendroctonus spp. in ponderosa pine slash are discussed.

According to the Swedish Forestry Act, environmental protection is required within forest operations regardless of forest ownership. This thesis examines the extent to which regulations issued by the National Board of Forestry are implemented in clearcuttings. Different factors contributing to the outcome of environmental protection are analyzed both from a top-down and a bottom-up perspec­tive. Empirically, the study combines field investigation of clearcuts, interviews with implementing actors, and evaluation of written prescriptions and advice on environ­mental protection. The Swedish forest-environmental legislation and implementation process is also compared to that of the U.S. and, especially, to the state of Cali­fornia . Conflicting goals within the Forestry Act and vague environmental guidelines leave the implementing agency officers with great discretion. Steering attempts by the Forestry Agency are in terms of friendly advice and information. No breaches of the regulations were taken to court during 1980-1986 although this is formally possible. There is an average compliance of approximately fifty per cent of the required environmental measures. Aesthetic values are taken into account to a greater extent than pure floristic and faunistic ones. Economic considerations and harvest technology contribute to a low degree of environmental protection. Forest machines are inadequately suited for protecting single, environmentally valuable trees and they frequently cause deep tracks. Inadequate environmental knowledge and insufficient pre-harvest environmental planning also affect environ­mental performance negatively. Generally, economic considerations contribute to the low priority to environ­mental protection given by the implementing actors compared to timber production. Economic inducements counteract environmental protection. It is generally rare that environmentalists and other public interests affected by forest operations are consulted. Environmentalists however influence indirectly through political pressure to legislate, participation in the consultation process before legislation is enacted, and mass-media attention. / digitalisering@umu