Korean pine（Pinus koraiensis） and broadleaved mixed forest in Northeast China has been changed regressively into secondary forest with almost no conifers.Planting Korean pine trees under the canopy of secondary fore...Korean pine（Pinus koraiensis） and broadleaved mixed forest in Northeast China has been changed regressively into secondary forest with almost no conifers.Planting Korean pine trees under the canopy of secondary forest is a feasible approach for recovering Korean pine and broadleaved mixed forest.For establishing an effective growth promotion method for under-canopy planted young Korean pine trees,two stands were selected as the experiment plots,Stand A（planted in 1989） and Stand B（planted in 1982）,and an experiment of microenvironment regulation was conducted relying mainly on Opening degree（K=1,K=1.5,K=2,CK） in 2004.The results were shown that the adjustment had promoted growth of diameter and height of Korean pine planted in Stand A and Stand B,and had a significant influence on the growth rate of basal diameter,diameter at breast height and height in the two growth stands.The four years periodic increment of mean diameter and height of Korean pine planted in 1989 and in 1982 after regulation in K=1 level were 63.4%（D0） and 82.7%（H）,64.8%（D1.3） and 69.7%（H） higher than that of control respectively.Quantitative regulation had significant influence on specific leaf area of Korean pine planted in 1989,and the current year specific leaf area（SLA） was lager than perennial year SLA.Quality indexes of natural pruning capacity,normal form quotient and crown size was not significantly changed but shown a positive tendency.The regulation scheme of Opening degree K=1 might be proper for adjusting the microenvironment of Korean pine trees planted under the canopy of secondary forest when the Korean pine trees were in the growth period of 15 to 26 years old in the experiment region.展开更多
We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds. Seeds treated with KNO3 and germinated at 25 ℃ followed by 5 ℃ had sig...We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds. Seeds treated with KNO3 and germinated at 25 ℃ followed by 5 ℃ had significantly higher germination percentages and germination potentials （51% and 49%, respectively）, compared with controls. These treated seeds also exhibited reduced germination initiation times （minimum of 48 days）, and elevated germination rate indices （up to 97）. The germination of seeds subjected to long-term cold storage （2 years at 0-5 ℃） was also significantly improved by 3 days of 4% KNO3 pretreatment before germinating under a variable temperature regimen （5 ℃ followed by 25 ℃, and followed by 5 ℃）. Germination percentages and germination potentials for these cold-stored seeds reached 67% and 54%, respectively, and the germination rate index increased to 126.99. Pretreatment of mountain ash seeds with KNO3 represents a practical, effective, and pollution-free method for improving germination, and can be implemented easily within a variety of nursery settings.展开更多
In recent years, researches on rural human capital are of great concern, but for how to effectively use the rural human capital is scanty, and thus, the transfer of rural human capital becomes a kind of way to solve r...In recent years, researches on rural human capital are of great concern, but for how to effectively use the rural human capital is scanty, and thus, the transfer of rural human capital becomes a kind of way to solve rural human capital utilization. A portion of China rural human capital has been successful transferred, however, because of the restrain of their conditions, they can only be engaged in some low level work. In China rural areas, there are a lot of rural human capitals who are not successful transferred. How to successfully transfer the rest of this part rural human capital and how to make them play roles will be an important task. In this paper, according to the practical situations, we first defined the rural human capital, and then briefly summarized the importance of human capital transfer. At last, we found out the restriction factors of rural human capital transfer in China, and put forward some suggestions and measures to solve the problems.展开更多
基金supported by the Project of AGRFUND from Ministry of Science and Technology of the People's Republic of China (Project No. 2007GB24320427)
文摘Korean pine（Pinus koraiensis） and broadleaved mixed forest in Northeast China has been changed regressively into secondary forest with almost no conifers.Planting Korean pine trees under the canopy of secondary forest is a feasible approach for recovering Korean pine and broadleaved mixed forest.For establishing an effective growth promotion method for under-canopy planted young Korean pine trees,two stands were selected as the experiment plots,Stand A（planted in 1989） and Stand B（planted in 1982）,and an experiment of microenvironment regulation was conducted relying mainly on Opening degree（K=1,K=1.5,K=2,CK） in 2004.The results were shown that the adjustment had promoted growth of diameter and height of Korean pine planted in Stand A and Stand B,and had a significant influence on the growth rate of basal diameter,diameter at breast height and height in the two growth stands.The four years periodic increment of mean diameter and height of Korean pine planted in 1989 and in 1982 after regulation in K=1 level were 63.4%（D0） and 82.7%（H）,64.8%（D1.3） and 69.7%（H） higher than that of control respectively.Quantitative regulation had significant influence on specific leaf area of Korean pine planted in 1989,and the current year specific leaf area（SLA） was lager than perennial year SLA.Quality indexes of natural pruning capacity,normal form quotient and crown size was not significantly changed but shown a positive tendency.The regulation scheme of Opening degree K=1 might be proper for adjusting the microenvironment of Korean pine trees planted under the canopy of secondary forest when the Korean pine trees were in the growth period of 15 to 26 years old in the experiment region.
文摘We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds. Seeds treated with KNO3 and germinated at 25 ℃ followed by 5 ℃ had significantly higher germination percentages and germination potentials （51% and 49%, respectively）, compared with controls. These treated seeds also exhibited reduced germination initiation times （minimum of 48 days）, and elevated germination rate indices （up to 97）. The germination of seeds subjected to long-term cold storage （2 years at 0-5 ℃） was also significantly improved by 3 days of 4% KNO3 pretreatment before germinating under a variable temperature regimen （5 ℃ followed by 25 ℃, and followed by 5 ℃）. Germination percentages and germination potentials for these cold-stored seeds reached 67% and 54%, respectively, and the germination rate index increased to 126.99. Pretreatment of mountain ash seeds with KNO3 represents a practical, effective, and pollution-free method for improving germination, and can be implemented easily within a variety of nursery settings.
基金Supported by Model of New Generation Migrant Laborers' Quality Construction in Heilongjiang Province Based on Sociology Net(GZ11D202)Post-crisis Migrant Workers Returning Home for Entrepreneurial(10C011)+1 种基金Urbanization of Heilongjiang Province and Ecological Interactive Mode(12B033)Evaluation for Urban and Rural Employment and Manpower in Heilongjiang Province(11552020)
文摘In recent years, researches on rural human capital are of great concern, but for how to effectively use the rural human capital is scanty, and thus, the transfer of rural human capital becomes a kind of way to solve rural human capital utilization. A portion of China rural human capital has been successful transferred, however, because of the restrain of their conditions, they can only be engaged in some low level work. In China rural areas, there are a lot of rural human capitals who are not successful transferred. How to successfully transfer the rest of this part rural human capital and how to make them play roles will be an important task. In this paper, according to the practical situations, we first defined the rural human capital, and then briefly summarized the importance of human capital transfer. At last, we found out the restriction factors of rural human capital transfer in China, and put forward some suggestions and measures to solve the problems.
