The stand growth and yield dynamic models for Larch in Jilin Province were developed based on the forest growth theories with the forest continuous inventory data. The results indicated that the developed models had h...The stand growth and yield dynamic models for Larch in Jilin Province were developed based on the forest growth theories with the forest continuous inventory data. The results indicated that the developed models had high precision, and they could be used for the updating data of inventory of planning and designing and optimal decision of forest management.展开更多
Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regener...Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regeneration level of forest resources and the diverse ecological value functions. In this article, the mainstream model paradigm of forest economics, that is, the basic framework of the Faustmann model and its evolution process are made in a more detailed explanation, especially the extended model including considered silvicultural effort, tax subsidies, risk dynamic management, and forest regeneration factors are made in more detailed explanations. This article concludes with the future further research directions of forest economics, including the design of dynamic models that includes considered uneven-aged forest management, non-timber goods and services, dynamic forest models. The research reflects the general trend of interdisciplinary and cross-border.展开更多
Forest degradation and biomass damage resulting from logging is currently difficult to evaluate with satellite images, but contributes substantially to carbon emissions in the tropics. To address this situation, we mo...Forest degradation and biomass damage resulting from logging is currently difficult to evaluate with satellite images, but contributes substantially to carbon emissions in the tropics. To address this situation, we modelled how changes in the minimum felling diameter affect stem density, basal area and the related carbon biomass at the end of the felling cycle （30 years） in a semi-deciduous natural forest in Cameroon. With new MFDs estimates, at 7% logging damage rate, we found that the stem density of initially harvestable trees reduces from 12.3 （50.4 MgC·ha^-1） to 6.7 （32.5 MgC·ha^-1） trees per ha and the number of initial residual trees increases from 80 （18.9MgC·ha^-1） to 85.7 （36.8 MgC·ha^-1） trees per ha. This corresponds to an avoided damage estimated at 17.9 MgC·ha^-1. We also found that increasing mortality and damage intensity also increases the damage on carbon biomass estimated to be 8.9 MgC·ha^-1 at 10% or to be 17.4 MgC.hal at 15% logging damage. Overall, our study shows that proper determination of MFD of logged species taking into consideration their capacity of reconstitution and the Reduced Impact Logging can avoid the loss of up to 35 MgC·ha^-1.展开更多
Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification ...Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification of Landsat TM satellite images from 1992, 2000, and 2009, with a maximum likelihood algorithm. In 2009, the forest cover was 10.3% of the land area of Chitral(60,000 ha). The deforestation rate increased from 0.14% per annum in 1992–2000 to 0.54% per annum in 2000–2009, with 3,759 ha forest lost over the 17 years. The spatial drivers of deforestation were investigated using a cellular automaton modelling technique to project future forest conditions. Accessibility(elevation, slope), population density, distance to settlements, and distance to administrative boundary were strongly associated with neighbourhood deforestation. A model projection showed a further loss of 23% of existing forest in Chitral tehsil by 2030, and degradation of 8%, if deforestation continues at the present rate. Arandu Union Council, with 2212 households, will lose 85% of its forest. Local communities have limited income resources and high poverty and are heavily dependent on non-timber forest products for their livelihoods. Continued deforestation will further worsen their livelihood conditions, thus improved conservation efforts are essential.展开更多
文摘The stand growth and yield dynamic models for Larch in Jilin Province were developed based on the forest growth theories with the forest continuous inventory data. The results indicated that the developed models had high precision, and they could be used for the updating data of inventory of planning and designing and optimal decision of forest management.
基金funded by the Humanities and So-cial Sciences Youth Fund Program under Ministry of Education and the program name is "The research about risk avoidance behavior in the production process of Chinese farmers" (Grant no.09YJC790214)
文摘Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regeneration level of forest resources and the diverse ecological value functions. In this article, the mainstream model paradigm of forest economics, that is, the basic framework of the Faustmann model and its evolution process are made in a more detailed explanation, especially the extended model including considered silvicultural effort, tax subsidies, risk dynamic management, and forest regeneration factors are made in more detailed explanations. This article concludes with the future further research directions of forest economics, including the design of dynamic models that includes considered uneven-aged forest management, non-timber goods and services, dynamic forest models. The research reflects the general trend of interdisciplinary and cross-border.
文摘Forest degradation and biomass damage resulting from logging is currently difficult to evaluate with satellite images, but contributes substantially to carbon emissions in the tropics. To address this situation, we modelled how changes in the minimum felling diameter affect stem density, basal area and the related carbon biomass at the end of the felling cycle （30 years） in a semi-deciduous natural forest in Cameroon. With new MFDs estimates, at 7% logging damage rate, we found that the stem density of initially harvestable trees reduces from 12.3 （50.4 MgC·ha^-1） to 6.7 （32.5 MgC·ha^-1） trees per ha and the number of initial residual trees increases from 80 （18.9MgC·ha^-1） to 85.7 （36.8 MgC·ha^-1） trees per ha. This corresponds to an avoided damage estimated at 17.9 MgC·ha^-1. We also found that increasing mortality and damage intensity also increases the damage on carbon biomass estimated to be 8.9 MgC·ha^-1 at 10% or to be 17.4 MgC.hal at 15% logging damage. Overall, our study shows that proper determination of MFD of logged species taking into consideration their capacity of reconstitution and the Reduced Impact Logging can avoid the loss of up to 35 MgC·ha^-1.
基金funded by the Ministry of Foreign Affairs,Norway and Swedish International Development Agency(Sida)supported by the United States Agency for International Development(USAID)National Aeronautics and Space Administration(NASA)
文摘Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification of Landsat TM satellite images from 1992, 2000, and 2009, with a maximum likelihood algorithm. In 2009, the forest cover was 10.3% of the land area of Chitral(60,000 ha). The deforestation rate increased from 0.14% per annum in 1992–2000 to 0.54% per annum in 2000–2009, with 3,759 ha forest lost over the 17 years. The spatial drivers of deforestation were investigated using a cellular automaton modelling technique to project future forest conditions. Accessibility(elevation, slope), population density, distance to settlements, and distance to administrative boundary were strongly associated with neighbourhood deforestation. A model projection showed a further loss of 23% of existing forest in Chitral tehsil by 2030, and degradation of 8%, if deforestation continues at the present rate. Arandu Union Council, with 2212 households, will lose 85% of its forest. Local communities have limited income resources and high poverty and are heavily dependent on non-timber forest products for their livelihoods. Continued deforestation will further worsen their livelihood conditions, thus improved conservation efforts are essential.
