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Browsing by Subject "eri-ikäisrakenteinen"

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  • Metsän erirakenteisuutta edistävien hakkuiden kannattavuustarkastelu metsäaluetasolla 
    Hämäläinen, Elias (2011)
    The aim of this study was to compare economics of three different forest management scenarios in Central Finland: a single-tree selection system, a group selection system and forest management activities under Finnish Forest Management Practice Recommendations which are commonly in use in Finland. Single-tree and group selection systems are natural disturbance-based forest harvesting methods which are used to create an small-scale variation of habitats. These methods may be feasible especially in specific forest areas where the goal is to maintain the biodiversity, landscape and multiple forest use in addition to commercial use. An area managed under selection cuttings results in an uneven-aged forest structure where the diameter distribution of trees reminds the reverse-J shaped curve. Natural regeneration and periodic harvests of large sawtimber-sized trees are the most important financial benefits of uneven-aged management. However, it is still uncertain does the uneven-aged management succeed in circumstances of Finland. This study evaluated economic effects of the simulated transformation from even-aged to uneven-aged structure in Isojärvi Environmentally Valuable Forest which is under the administration of Metsähallitus and situated in Kuhmoinen. The data used in the study consist 405 Norway spruce dominated stands and 636 hectares of forest land. All simulations were made for 40 years from present with SIMO software using 3 % and 5 % interest rates. Individual tree models were used in forest development prediction and 5-year time steps in simulations of forestry operations. The aim of these simulations was to find out cutting volumes of timber assortments, discounted cashflows as well as the amount of growing stock and its variation. The automated mobile phone follow-up system with MobiDoc2 application was used to collect acceleration data, GPS-data and input data of forest machines. These data were then used to model harvesting unit costs. Finally, net present values were calculated for every management scenarios and discounted harvesting costs were reduced of these NPVs. Study results show that the NPV calculated with an interest rate of 3 % was highest for Forest Management Practice Recommendations (8076 €/ha). The NPV for single-tree selection was 91 % (7420 €/ha) and the NPV for group selection system was 99 % (8076 €/ha) of Forest Management Practice Recommendations. Comparative statics indicated that calculating NPVs with an interest rate of 5 % did not significantly affected the differences between NPVs. The unit cost of single-tree harvesting was 0,8 €/m3 lower than for thinning and 7,2 €/m3 higher than for clear cutting. The unit cost of group selection was 0,7 €/m3 higher than for clear cutting. Study results show that transformation from even-aged to uneven-aged forest structure creates economic losses even if the trees are old and the cuttings are intensive. The economic loss is an opportunity cost of continuous cover forestry.
  • Ympäristöarvojen liittäminen metsäekonomisiin malleihin 
    Mörä, Lauri (2013)
    Forests provide not just timber, but also a host of other benefits, such as carbon sequestration, biodiversity, recreational opportunities and beautiful scenery. From an economic perspective, such a multiplicity of utili-zation options of forests may be interpreted as joint production. However, these utilization options are often competing at least to some extent. In a changing society, the importance of non-timber benefits are increas-ing, and forest management is subject to more stringent environmental requirements. Studies have shown that targets for the use of forests have become more varied, and the interest in alternative methods of forest management has increased. The aim of this study was to create an overall picture of how environmental values are taken into account in forest economics at the stand level. Special attention was paid to uneven-aged forest management, since the method is often considered more appropriate for multi-objective forest management. Uneven-aged man-agement of forests may enable a more efficient joint production of many benefits. Nevertheless, to maintain e.g. forest biodiversity in uneven-aged stand, there is still need to ensure a robust amount of individual trees and dead wood by leaving sufficient number of retention trees. Hence, valuing environmental benefits may well have an impact on optimal stand management. In this study an optimization model is formulated to analyze uneven-aged forest management when stand-ing old trees have an environmental value. Optimization problem was solved without any time constraints or a predetermined steady state. The model was tested with both linear and nonlinear environmental valuation function. In addition, it was examined how relative value of environmental benefits and interest rate affect the structure of the stand and harvest revenues. As an alternative method, this study presented optimization of harvests while satisfying a constraint intended to meet an environmental management objective. This constraint was used to study the opportunity cost of retention trees. In conclusion, the results indicated that the valuation of environmental benefits affects the optimal harvest-ing and stand structure. When raising the interest rate, fewer retention trees should be left to the stand. The number of retention trees affects present value of harvest revenues, and the optimal solution between com-peting benefits depends on the preferences of the decision maker.

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