A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services an...A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services and classified forest management, we hypothesized that the ecological-forest provides ecological services, whereas commercial-forest supplies wood and timber production, and the influences of the growth of population, social-economic development target, forest management methods and the technology changes on forest resources were also taken into account. The prediction reveals that the demand of total forestland of China will be 244.8, 261.2 and 362.2 million ha by the year 2010, 2020 and 2050, respectively. The results demonstrated that China will be confronted with a shortage of forest resources, especially with lack of ecological-oriented forests, in the future. It is suggested that sustainable management of forest resources must be reinforced and more attention should be drown no enhancing the service function of forest ecosystem.展开更多
Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced fac...Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced factors changed the eco-environment by reclaiming forestlands, the intensity of man-made soil erosion in reclaimed lands was 1,000 times more than that of natural erosion in forestlands. From the analysis of soil physical and mechanical properties, the clay content and physical clay content decreased 2.74% and 3.01% respectively, and the >0.25 mm water stable aggregate content decreased 58.7%, the soil unit weight increased and the soil shear strength decreased, all of which were easier to cause soil erosion. The results of the correlation analysis showed that the >0.25 mm water stable aggregate content was the greatest influencing factor on soil erosion, the partial correlated coefficient was 0.9728, and then were soil coarse grain and soil shear strength, the partial correlated coefficients being 0.8879 and 0.6020 respectively. The relationships between the >0.25 mm water stable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first and seventh years were the turning years of the soil erosion intensity after the forestland reclamation. The degenerative eroded soil and eco-environment formed the peculiar erosion environment, which aggravated the soil erosion rapidly.展开更多
Reconstructing long-term changes of forest cover(FC)can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment.Historical maps conta...Reconstructing long-term changes of forest cover(FC)can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment.Historical maps contain a wealth of forest related information and can provide first-hand data for studying the changes in FC over a long time period.Taking the reconstruction of FC in Taiwan Province from 1910-2010 as the research object,we used map extraction and mining methods to extract forest distribution information from historical forest thematic survey maps,topographic and land cover maps,and reconstructed the spatiotemporal patterns of FC in Taiwan from 1910-2010.The results show that:first,the relative bias of the FC area extracted from the historical maps of Taiwan was below 8%,meaning the FC information contained in maps is highly accurate.Second,the FC of Taiwan has generally declined in the past 100 years.From 1910-2010,the forest area declined from 2.62×10^(6) ha to 2.47×10^(6) ha,with relatively obvious forest reduction having occurred.In stages,the forest area of Taiwan decreased by 26.39×10^(4) ha from 1910 to 1950;and increased by 10.53×10^(4) ha during the period 1950-2010.Forest reduction was obvious during the Japanese occupation period,while forest increase was remarkable during the Kuomintang period.Third,during the study period,the total area of patches maintained as forests was 2.17×10^(6) ha with little change in the overall pattern,and forests were mainly distributed in the mountain regions.The loss of forest mainly occurred in the plains,with expanding forest areas mainly in the mountain regions at high elevations and on steep slopes.Fourth,land clearing for agriculture during the Japanese occupation period has been the important driver of forest reduction in Taiwan over the past century.After retreated to Taiwan,the Kuomintang government introduced effective and remarkable reforms that led to effective restoration of forest vegetation in many areas where forests had previously disappeared.展开更多
Background: Carbon sequestration through recommended forest management practices is an ecosystem service that helps mitigate climate change and its impacts while generating carbon credits for forestland owners to sell...Background: Carbon sequestration through recommended forest management practices is an ecosystem service that helps mitigate climate change and its impacts while generating carbon credits for forestland owners to sell in cap-and-trade programs. The California’s cap-and-trade program (California’s carbon market hereafter) allows forestland owners from any part of the contiguous United States to supply carbon credits to compliance entities. In this study, we estimate South Carolina (SC) private forestland owners’willingness to accept compensations to participate in the California’s carbon market using a contingent valuation method. Results: We estimate forestland owners’mean willingness to accept as$67 per acre per year. Our results reveal higher probability of participation of forestland owners with interests in preserving forest ecosystems than those who do not. Additionally, forestland owners who trust in information about climate change from scientists or government are willing to participate more than those who do not. Conclusions: Various factors hinder landowners’ability to participate in carbon markets. Forestland owners in SC consider legislative uncertainty and long-time commitment as the main barriers to participation in California’s carbon market. From this research, average forestland tenure in SC is 27 years, which is far less than the 100-year time commitment of the California’s carbon market. Of those who agreed to participate, choosing between adopting and not adopting any of the three main forest management practices in the California’s carbon market:28% are likely to adopt improved forest management (IFM) practices, 24% are likely to adopt reforestation due to understocked forestlands, and 14% are likely to adopt avoided conversion. In another development, the concept of aggregation has dominated discussions in the California’s carbon market of late. It is an advocacy to include small-scale forestlands in the California’s carbon market. To aggregate, different forestland owners will combine their forestlands to participate. We find that 79% of SC forestland owners are willing to aggregate to participate. However, this research is unable to determine how much total forestland is available in SC for carbon market. We recommend future research in the State on forestland owners’participation in carbon market should consider evaluating forestland availability.展开更多
Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and...Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm waterstable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength decreased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable aggregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change of eco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.展开更多
Forestland use right reforms are allowing forest farmers to freely transact their land and reap new profits Hubei Province farmer Huang Huabing contracted 30 hectares of
In order to understand the impact of demographic structure on paddy and forestland managementafter the convening of the Third Plenary Session of the 11th CPC (Communist Party of China) CentralCommittee and the impleme...In order to understand the impact of demographic structure on paddy and forestland managementafter the convening of the Third Plenary Session of the 11th CPC (Communist Party of China) CentralCommittee and the implementation of the Household Responsibility System (the government divided upland among peasants for cultivating and the peasants sell a set part of their produced goods to thegovernment at stipulated prices by contract in the countryside of China), 147 households in 6 villages,belonging to Xiangtan County and Zhuzhou County in Hunan Province, were selected as research samples,and interview, questionnaire survey and second hand data analyzing were used as the methods. The resultsshowed: Persons with different ages had different ideas, and young peasants would like to work in townsor cities for more income, so they used and depended on land less; In terms of sex, the male was still themain user of land, and therefore the ability, idea and activity of male played an important role in landmanagement; Generally, the labors with better educational background grasped more knowledge andtechnologies, and they had more opportunity to get jobs and had better working condition and moreincome in town or cities, so they depended on and used land less.展开更多
基金the National Key Technologies R&D Program of China (2006BAD03A09)the National Science Fund of China (40841001)
文摘A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services and classified forest management, we hypothesized that the ecological-forest provides ecological services, whereas commercial-forest supplies wood and timber production, and the influences of the growth of population, social-economic development target, forest management methods and the technology changes on forest resources were also taken into account. The prediction reveals that the demand of total forestland of China will be 244.8, 261.2 and 362.2 million ha by the year 2010, 2020 and 2050, respectively. The results demonstrated that China will be confronted with a shortage of forest resources, especially with lack of ecological-oriented forests, in the future. It is suggested that sustainable management of forest resources must be reinforced and more attention should be drown no enhancing the service function of forest ecosystem.
基金National Natural Science Foundation of China No.19832060
文摘Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced factors changed the eco-environment by reclaiming forestlands, the intensity of man-made soil erosion in reclaimed lands was 1,000 times more than that of natural erosion in forestlands. From the analysis of soil physical and mechanical properties, the clay content and physical clay content decreased 2.74% and 3.01% respectively, and the >0.25 mm water stable aggregate content decreased 58.7%, the soil unit weight increased and the soil shear strength decreased, all of which were easier to cause soil erosion. The results of the correlation analysis showed that the >0.25 mm water stable aggregate content was the greatest influencing factor on soil erosion, the partial correlated coefficient was 0.9728, and then were soil coarse grain and soil shear strength, the partial correlated coefficients being 0.8879 and 0.6020 respectively. The relationships between the >0.25 mm water stable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first and seventh years were the turning years of the soil erosion intensity after the forestland reclamation. The degenerative eroded soil and eco-environment formed the peculiar erosion environment, which aggravated the soil erosion rapidly.
基金National Natural Science Foundation of China(41801065)National Key R&D Program of China(2019YFA0606603)National Undergraduate Training Program for Innovation and Entrepreneurship(202010284073Y)。
文摘Reconstructing long-term changes of forest cover(FC)can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment.Historical maps contain a wealth of forest related information and can provide first-hand data for studying the changes in FC over a long time period.Taking the reconstruction of FC in Taiwan Province from 1910-2010 as the research object,we used map extraction and mining methods to extract forest distribution information from historical forest thematic survey maps,topographic and land cover maps,and reconstructed the spatiotemporal patterns of FC in Taiwan from 1910-2010.The results show that:first,the relative bias of the FC area extracted from the historical maps of Taiwan was below 8%,meaning the FC information contained in maps is highly accurate.Second,the FC of Taiwan has generally declined in the past 100 years.From 1910-2010,the forest area declined from 2.62×10^(6) ha to 2.47×10^(6) ha,with relatively obvious forest reduction having occurred.In stages,the forest area of Taiwan decreased by 26.39×10^(4) ha from 1910 to 1950;and increased by 10.53×10^(4) ha during the period 1950-2010.Forest reduction was obvious during the Japanese occupation period,while forest increase was remarkable during the Kuomintang period.Third,during the study period,the total area of patches maintained as forests was 2.17×10^(6) ha with little change in the overall pattern,and forests were mainly distributed in the mountain regions.The loss of forest mainly occurred in the plains,with expanding forest areas mainly in the mountain regions at high elevations and on steep slopes.Fourth,land clearing for agriculture during the Japanese occupation period has been the important driver of forest reduction in Taiwan over the past century.After retreated to Taiwan,the Kuomintang government introduced effective and remarkable reforms that led to effective restoration of forest vegetation in many areas where forests had previously disappeared.
基金funded by the South Carolina Natural Resources Conservation Service(SC NRCS)with grant number 2021917
文摘Background: Carbon sequestration through recommended forest management practices is an ecosystem service that helps mitigate climate change and its impacts while generating carbon credits for forestland owners to sell in cap-and-trade programs. The California’s cap-and-trade program (California’s carbon market hereafter) allows forestland owners from any part of the contiguous United States to supply carbon credits to compliance entities. In this study, we estimate South Carolina (SC) private forestland owners’willingness to accept compensations to participate in the California’s carbon market using a contingent valuation method. Results: We estimate forestland owners’mean willingness to accept as$67 per acre per year. Our results reveal higher probability of participation of forestland owners with interests in preserving forest ecosystems than those who do not. Additionally, forestland owners who trust in information about climate change from scientists or government are willing to participate more than those who do not. Conclusions: Various factors hinder landowners’ability to participate in carbon markets. Forestland owners in SC consider legislative uncertainty and long-time commitment as the main barriers to participation in California’s carbon market. From this research, average forestland tenure in SC is 27 years, which is far less than the 100-year time commitment of the California’s carbon market. Of those who agreed to participate, choosing between adopting and not adopting any of the three main forest management practices in the California’s carbon market:28% are likely to adopt improved forest management (IFM) practices, 24% are likely to adopt reforestation due to understocked forestlands, and 14% are likely to adopt avoided conversion. In another development, the concept of aggregation has dominated discussions in the California’s carbon market of late. It is an advocacy to include small-scale forestlands in the California’s carbon market. To aggregate, different forestland owners will combine their forestlands to participate. We find that 79% of SC forestland owners are willing to aggregate to participate. However, this research is unable to determine how much total forestland is available in SC for carbon market. We recommend future research in the State on forestland owners’participation in carbon market should consider evaluating forestland availability.
文摘Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm waterstable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength decreased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable aggregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change of eco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.
文摘Forestland use right reforms are allowing forest farmers to freely transact their land and reap new profits Hubei Province farmer Huang Huabing contracted 30 hectares of
文摘In order to understand the impact of demographic structure on paddy and forestland managementafter the convening of the Third Plenary Session of the 11th CPC (Communist Party of China) CentralCommittee and the implementation of the Household Responsibility System (the government divided upland among peasants for cultivating and the peasants sell a set part of their produced goods to thegovernment at stipulated prices by contract in the countryside of China), 147 households in 6 villages,belonging to Xiangtan County and Zhuzhou County in Hunan Province, were selected as research samples,and interview, questionnaire survey and second hand data analyzing were used as the methods. The resultsshowed: Persons with different ages had different ideas, and young peasants would like to work in townsor cities for more income, so they used and depended on land less; In terms of sex, the male was still themain user of land, and therefore the ability, idea and activity of male played an important role in landmanagement; Generally, the labors with better educational background grasped more knowledge andtechnologies, and they had more opportunity to get jobs and had better working condition and moreincome in town or cities, so they depended on and used land less.
