The current trend of forest management in many countries is reduced use of clear-felling and planting, and increased use of continuous cover management. In Finland, the new forest act of 2014 made all types of cutting...The current trend of forest management in many countries is reduced use of clear-felling and planting, and increased use of continuous cover management. In Finland, the new forest act of 2014 made all types of cuttings equally allowable on the condition that if the post-cutting residual stand basal area is too low, the stand must be regenerated within certain time frame. Forest landowner can freely choose between even-and uneven-aged management. This study developed a method for opti-mizing the timing and type of cuttings without the need to categorize the management system as either even-aged or uneven-aged. A management system that does not set any requirements on the sequence of post-cutting diameter distributions is called any-aged management. Planting or sow-ing was used when stand basal area fell below the required minimum basal area and the amount of advance regeneration was less than required in the regulations. When the cuttings of 200 stands managed earlier with even-aged silviculture were optimized with the developed system, final felling followed by artificial regeneration was selected for almost 50%of stands. Reduction of the minimum basal area limit greatly decreased the use of artificial regeneration but improved profitability, suggesting that the truly optimal management would be to use natural regeneration in financially mature stands. The optimal type of thinning was high thinning in 97-99%of cases. It was calculated that the minimum basal area re-quirement reduced the mean net present value of the stands by 12-16%when discount rate was 3-5%.展开更多
Background： Forest ecosystems are increasingly seen as multi-functional production systems, which should provide, besides timber and economic benefits, also other ecosystem services related to biological diversity, r...Background： Forest ecosystems are increasingly seen as multi-functional production systems, which should provide, besides timber and economic benefits, also other ecosystem services related to biological diversity, recreational uses and environmental functions of forests. This study analyzed the performance of even-aged rotation forest management （RFM）, continuous cover forestry （CCF） and any-aged forestry （AAF） in the production of ecosystem services. AAF allows both even-aged and uneven-aged management schedules. The ecosystem services included in the analyses were net present value, volume of harvested timber, cowberry and bilberry yields, scenic value of the forest, carbon balance and suitability of the forest to Siberian jay. Methods： Data envelopment analysis was used to derive numerical efficiency ratios for the three management systems. Efficiency ratio is the sum of weighted outputs （ecosystem services） divided by the sum of weighted inputs. The linear programing model proposed by Charnes, Cooper and Rhodes was used to derive the weights for calculating efficiency scores for the silvicultural systems. Results and conclusions： CCF provided more ecosystem services than RFM, and CCF was more efficient than RFM and AAF in the production of ecosystem services. Multi-objective management provided more ecosystem services （except harvested timber） than single-objective management that maximized economic profitability. The use of low discount rate （resulting in low cutting level and high growing stock volume） led to better supply of most ecosystems services than the use of high discount rate. RFM where NPV was maximized with high discount rate led to particularly poor provision of most ecosystem services. In CCF the provision of ecosystem services was less sensitive to changes in discount rate and management objective than in RFM.展开更多
文摘The current trend of forest management in many countries is reduced use of clear-felling and planting, and increased use of continuous cover management. In Finland, the new forest act of 2014 made all types of cuttings equally allowable on the condition that if the post-cutting residual stand basal area is too low, the stand must be regenerated within certain time frame. Forest landowner can freely choose between even-and uneven-aged management. This study developed a method for opti-mizing the timing and type of cuttings without the need to categorize the management system as either even-aged or uneven-aged. A management system that does not set any requirements on the sequence of post-cutting diameter distributions is called any-aged management. Planting or sow-ing was used when stand basal area fell below the required minimum basal area and the amount of advance regeneration was less than required in the regulations. When the cuttings of 200 stands managed earlier with even-aged silviculture were optimized with the developed system, final felling followed by artificial regeneration was selected for almost 50%of stands. Reduction of the minimum basal area limit greatly decreased the use of artificial regeneration but improved profitability, suggesting that the truly optimal management would be to use natural regeneration in financially mature stands. The optimal type of thinning was high thinning in 97-99%of cases. It was calculated that the minimum basal area re-quirement reduced the mean net present value of the stands by 12-16%when discount rate was 3-5%.
文摘Background： Forest ecosystems are increasingly seen as multi-functional production systems, which should provide, besides timber and economic benefits, also other ecosystem services related to biological diversity, recreational uses and environmental functions of forests. This study analyzed the performance of even-aged rotation forest management （RFM）, continuous cover forestry （CCF） and any-aged forestry （AAF） in the production of ecosystem services. AAF allows both even-aged and uneven-aged management schedules. The ecosystem services included in the analyses were net present value, volume of harvested timber, cowberry and bilberry yields, scenic value of the forest, carbon balance and suitability of the forest to Siberian jay. Methods： Data envelopment analysis was used to derive numerical efficiency ratios for the three management systems. Efficiency ratio is the sum of weighted outputs （ecosystem services） divided by the sum of weighted inputs. The linear programing model proposed by Charnes, Cooper and Rhodes was used to derive the weights for calculating efficiency scores for the silvicultural systems. Results and conclusions： CCF provided more ecosystem services than RFM, and CCF was more efficient than RFM and AAF in the production of ecosystem services. Multi-objective management provided more ecosystem services （except harvested timber） than single-objective management that maximized economic profitability. The use of low discount rate （resulting in low cutting level and high growing stock volume） led to better supply of most ecosystems services than the use of high discount rate. RFM where NPV was maximized with high discount rate led to particularly poor provision of most ecosystem services. In CCF the provision of ecosystem services was less sensitive to changes in discount rate and management objective than in RFM.
