Assessment of regional forest carbon stocks and underlying controls is critical for guiding forest management in the context of carbon sequestration. We investigated the variations in tree biomass carbon stocks relati...Assessment of regional forest carbon stocks and underlying controls is critical for guiding forest management in the context of carbon sequestration. We investigated the variations in tree biomass carbon stocks relating to forest types, and estimated the total tree biomass carbon stocks and projected gains through natural stand development by 2020 and 2050 in the Daqing Mountain Nature Reserve based on Category II data of the Forest Inventory of Inner Mongolia for the period ending 2008. Over a total area of 388,577 ha,this nature reserve currently stores an estimated 2221 Gg C in tree aboveground biomass alone, with potential to grow by more than 30 % to reach 2938 Gg C by 2020 and nearly double to 4092 Gg C by 2050 through natural development of the existing forest stands. The tree biomass carbon density and potential gain in tree biomass carbon stocks vary markedly among forest types and with stand development.The variations in the potential change of tree biomass carbon density for the periods 2008–2020 and 2008–2050 among forest types partly reflect the varying relationships of tree biomass carbon density with stand age for different tree species, and partly are attributable to variations in the stand age structure among different forest types. Of the major forest types, the ranking of projected changes in tree biomass carbon density are not consistent with variations in the relationship between tree biomass carbon density and stand age, neither are they explainable by variations in stand age structures, implying the interactive effect between forest type and stand dynamics on temporal changes in tree biomass carbon density. Birch rank highest for future biomass carbon sequestration because of its dominance in cover area and better age structure for potential gain in tree biomass carbon stocks. Poplar and larch were out-performers compared to other forest types given their greater contribution to total tree biomass carbon stocks relative to their distributional areas. Findings in this study illustrate that protection and proper management of under-aged forests can deliver marked gains in biomass carbon sequestration. This is of great importance to policy-makers as well as to scientific communities in seeking effective solutions for adaptive forest management and mitigation of anthropogenic greenhouse gases emissions using forest ecosystems.展开更多
Owing to the technical innovation as well as a better understanding of gas exploration,nine giant gas fields have been successively discovered in the Sichuan Basin with cumulative proven gas reserves of 3.69 trillion ...Owing to the technical innovation as well as a better understanding of gas exploration,nine giant gas fields have been successively discovered in the Sichuan Basin with cumulative proven gas reserves of 3.69 trillion cubic meters,where the annual natural gas productivity ranks the second in China.The CNPC latest oil&gas resources evaluation results demonstrate that natural gas resources in the Sichuan Basin takes the first place among those petroliferous basins all over China,but its proved gas reserves is only 10%,so the exploration prospect is bright.Over the past decades,PetroChina Southwest Oil&Gas Field Company has made great efforts to complete its technical systems,improve gas pipeline networks,and streamline gas markets,laying a robust foundation for the natural gas development in the Sichuan Basin.To further enhance the natural gas reserves and productivity in this basin and to achieve the biggest gas province in China,this company presents the following major projects:progressive multi-strata exploration and development in the central Sichuan area,Safe and efficient development of high-sulfur gas fields in the northeastern Sichuan area,Demonstrative exploration and development of deep marine carbonate gas reservoirs in the northwestern Sichuan area,Exploitation and development of large Cambrian pre-salt structural gas reservoirs in the eastern Sichuan area,and Extensive and beneficial development of shale gas in southern Sichuan.As the key to the Southwest growth pole,the above projects cover all the important,hard and hot fields of the whole basin and multiple gas-bearing strata and layers.With all the projects fulfilled,natural gas productivity will be 25-29 billion cubic meters(bcm)in 2020,accounting for most parts of this company's whole planning production(30 bcm in total),and will reach up to 50-70 bcm in 2030.It is predicted that natural gas development in the Sichuan Basin will be in a golden era in the long term.展开更多
基金funded by the Program for Public–Welfare Forestry of the State Forestry Administration of China(Grant No.201104008)
文摘Assessment of regional forest carbon stocks and underlying controls is critical for guiding forest management in the context of carbon sequestration. We investigated the variations in tree biomass carbon stocks relating to forest types, and estimated the total tree biomass carbon stocks and projected gains through natural stand development by 2020 and 2050 in the Daqing Mountain Nature Reserve based on Category II data of the Forest Inventory of Inner Mongolia for the period ending 2008. Over a total area of 388,577 ha,this nature reserve currently stores an estimated 2221 Gg C in tree aboveground biomass alone, with potential to grow by more than 30 % to reach 2938 Gg C by 2020 and nearly double to 4092 Gg C by 2050 through natural development of the existing forest stands. The tree biomass carbon density and potential gain in tree biomass carbon stocks vary markedly among forest types and with stand development.The variations in the potential change of tree biomass carbon density for the periods 2008–2020 and 2008–2050 among forest types partly reflect the varying relationships of tree biomass carbon density with stand age for different tree species, and partly are attributable to variations in the stand age structure among different forest types. Of the major forest types, the ranking of projected changes in tree biomass carbon density are not consistent with variations in the relationship between tree biomass carbon density and stand age, neither are they explainable by variations in stand age structures, implying the interactive effect between forest type and stand dynamics on temporal changes in tree biomass carbon density. Birch rank highest for future biomass carbon sequestration because of its dominance in cover area and better age structure for potential gain in tree biomass carbon stocks. Poplar and larch were out-performers compared to other forest types given their greater contribution to total tree biomass carbon stocks relative to their distributional areas. Findings in this study illustrate that protection and proper management of under-aged forests can deliver marked gains in biomass carbon sequestration. This is of great importance to policy-makers as well as to scientific communities in seeking effective solutions for adaptive forest management and mitigation of anthropogenic greenhouse gases emissions using forest ecosystems.
文摘Owing to the technical innovation as well as a better understanding of gas exploration,nine giant gas fields have been successively discovered in the Sichuan Basin with cumulative proven gas reserves of 3.69 trillion cubic meters,where the annual natural gas productivity ranks the second in China.The CNPC latest oil&gas resources evaluation results demonstrate that natural gas resources in the Sichuan Basin takes the first place among those petroliferous basins all over China,but its proved gas reserves is only 10%,so the exploration prospect is bright.Over the past decades,PetroChina Southwest Oil&Gas Field Company has made great efforts to complete its technical systems,improve gas pipeline networks,and streamline gas markets,laying a robust foundation for the natural gas development in the Sichuan Basin.To further enhance the natural gas reserves and productivity in this basin and to achieve the biggest gas province in China,this company presents the following major projects:progressive multi-strata exploration and development in the central Sichuan area,Safe and efficient development of high-sulfur gas fields in the northeastern Sichuan area,Demonstrative exploration and development of deep marine carbonate gas reservoirs in the northwestern Sichuan area,Exploitation and development of large Cambrian pre-salt structural gas reservoirs in the eastern Sichuan area,and Extensive and beneficial development of shale gas in southern Sichuan.As the key to the Southwest growth pole,the above projects cover all the important,hard and hot fields of the whole basin and multiple gas-bearing strata and layers.With all the projects fulfilled,natural gas productivity will be 25-29 billion cubic meters(bcm)in 2020,accounting for most parts of this company's whole planning production(30 bcm in total),and will reach up to 50-70 bcm in 2030.It is predicted that natural gas development in the Sichuan Basin will be in a golden era in the long term.
