Reclaimed mined lands provide an excellent opportunity to sequester carbon and combat global warming. Carbon sequestration on reclaimed sites depend on age of reclamation, composition of species, geomining conditions ...Reclaimed mined lands provide an excellent opportunity to sequester carbon and combat global warming. Carbon sequestration on reclaimed sites depend on age of reclamation, composition of species, geomining conditions （soil characteristics） and prevailing climate. The aims of the present study were to calculate carbon （C）--stock of biomass of 4 years old plantation （dominated by Albizia lebbeck, Dalbergia sissoo and Bambusa arundinacea）, understorey vegetation and litter, soil organic carbon in reclaimed minesoil （RMS） and compare with reference forest site. Allometric equation was used for the estimation of biomass C stock and found 13.0 Mg C ha i （A lebbeck 7.8 Mg C ha-I, D sissoo 3.5 Mg C ha-l and B. arundincea 1.2 Mg C ha-l）, while stock of understorey vegetation was 0.98 Mg C ha-~. In RMS, C stock was 16.3 Mg C ha-1, out of which inorganic C contributed 1.7 g kg-l （8 % of total soil C）, Coal C 8.7 g kg^-1 （43 % of total soil C） and biogenic C 9.8 g kg^-1 （49 % of total soil C）. Total C stock in reclaimed site was calculated as 30.3 Mg C ha^-1（equivalent to 111 Mg CO2 ha-b. The study concluded that （i） coal C is responsible for overestimation of C stock in RMS （ii） Maximun C stock stored in aboveground biomass component and （iii） reclaimed mined lands will take approximately 17 years to reach the level of C stock of reference forest site in dry tropical climate.展开更多
Rice-wheat rotation and poplar afforestation are two typical land use types in the coastal reclaimed flatlands of eastern China. This study investigated two rice-wheat rotation lands （one reclaimed from 1995 to 2004 ...Rice-wheat rotation and poplar afforestation are two typical land use types in the coastal reclaimed flatlands of eastern China. This study investigated two rice-wheat rotation lands （one reclaimed from 1995 to 2004 and cultivated since 2005, RW1, and the other reclaimed from 1975 to 1995 and cultivated since 1996, RW2） and a poplar woodland （reclaimed from 1995 to 2004 and planted in 2004, PWl） to determine the effects of land use types and years of cultivation on soil microbial biomass and mineralizable carbon （C） in this coastal salt-affected region. The results showed that the soil in PWl remained highly salinized, whereas desalinization was observed in RWl. The total organic C （TOC） in the top soil of PWl and RW1 did not show significant differences, whereas at a soil depth of 20-30 cm, the TOC of RWl was approximately 40%-67% higher than that of PWl. The TOC of 0-30-cm soil in RW2 was approximately 37% higher than that in RW1. Microbial biomass C （MBC） and mineralizable C （MNC） exhibited the trend of RW2 〉 RWl 〉 PWl. Sufficient nutrition with more abundant C substrates resulted in higher MBC and MNC, and soil respiration rates were negatively correlated with C/N in RWl and RW2. Nutrient deficiency and high salinity played key roles in limiting MBC in PWl. These suggested that rice-wheat rotation was more beneficial than poplar afforestation for C accumulation and microbial biomass growth in the coastal salt-affected soils.展开更多
Wet granulation is a potential method to develop artificial aggregates.In this paper,the granulation of recycled alkali-activated slag powders with different particle size(d_(50) ranging between 12.9-127.7μm)distribu...Wet granulation is a potential method to develop artificial aggregates.In this paper,the granulation of recycled alkali-activated slag powders with different particle size(d_(50) ranging between 12.9-127.7μm)distributions were investigated in order to find how these affect on the engineering properties of the artificial aggregates.Blast furnace slag was added as co-binder in 10-30 wt.%during the granulation process and to enhance the properties,especially mechanical strength.The results show that the particle size of the raw material significantly affects the engineering properties of the produced aggregates,such as the crushing force(19-131.8 N),bulk density,water absorption,porosity and microstructure of the granules.The results show that granulation is a promising method to recycle alkali-activated materials as lightweight aggregates to replace natural aggregates.展开更多
文摘Reclaimed mined lands provide an excellent opportunity to sequester carbon and combat global warming. Carbon sequestration on reclaimed sites depend on age of reclamation, composition of species, geomining conditions （soil characteristics） and prevailing climate. The aims of the present study were to calculate carbon （C）--stock of biomass of 4 years old plantation （dominated by Albizia lebbeck, Dalbergia sissoo and Bambusa arundinacea）, understorey vegetation and litter, soil organic carbon in reclaimed minesoil （RMS） and compare with reference forest site. Allometric equation was used for the estimation of biomass C stock and found 13.0 Mg C ha i （A lebbeck 7.8 Mg C ha-I, D sissoo 3.5 Mg C ha-l and B. arundincea 1.2 Mg C ha-l）, while stock of understorey vegetation was 0.98 Mg C ha-~. In RMS, C stock was 16.3 Mg C ha-1, out of which inorganic C contributed 1.7 g kg-l （8 % of total soil C）, Coal C 8.7 g kg^-1 （43 % of total soil C） and biogenic C 9.8 g kg^-1 （49 % of total soil C）. Total C stock in reclaimed site was calculated as 30.3 Mg C ha^-1（equivalent to 111 Mg CO2 ha-b. The study concluded that （i） coal C is responsible for overestimation of C stock in RMS （ii） Maximun C stock stored in aboveground biomass component and （iii） reclaimed mined lands will take approximately 17 years to reach the level of C stock of reference forest site in dry tropical climate.
基金supported financially by the National Key Research and Development Program of China (Nos.2016YFD0200303, 2016YFC0501309, and 2016YFC0501201)the Project of the Science and Technology Service (STS) Network Initiative, Chinese Academy of Sciences (No.KFJ-SW-STS-141-2)+3 种基金the Independent Innovation Project of Jiangsu Agricultural Science & Technology, China (No.CX(15)1005)the Key Research and Development Program of Jiangsu Province, China (No.BE2015337)the National Key Technology R&D Program of China (No.2015BAD-01B03-4)the National Natural Science Foundation of China (No.41171181)
文摘Rice-wheat rotation and poplar afforestation are two typical land use types in the coastal reclaimed flatlands of eastern China. This study investigated two rice-wheat rotation lands （one reclaimed from 1995 to 2004 and cultivated since 2005, RW1, and the other reclaimed from 1975 to 1995 and cultivated since 1996, RW2） and a poplar woodland （reclaimed from 1995 to 2004 and planted in 2004, PWl） to determine the effects of land use types and years of cultivation on soil microbial biomass and mineralizable carbon （C） in this coastal salt-affected region. The results showed that the soil in PWl remained highly salinized, whereas desalinization was observed in RWl. The total organic C （TOC） in the top soil of PWl and RW1 did not show significant differences, whereas at a soil depth of 20-30 cm, the TOC of RWl was approximately 40%-67% higher than that of PWl. The TOC of 0-30-cm soil in RW2 was approximately 37% higher than that in RW1. Microbial biomass C （MBC） and mineralizable C （MNC） exhibited the trend of RW2 〉 RWl 〉 PWl. Sufficient nutrition with more abundant C substrates resulted in higher MBC and MNC, and soil respiration rates were negatively correlated with C/N in RWl and RW2. Nutrient deficiency and high salinity played key roles in limiting MBC in PWl. These suggested that rice-wheat rotation was more beneficial than poplar afforestation for C accumulation and microbial biomass growth in the coastal salt-affected soils.
基金support received for the project DeConcrete Eco-Efficient Arctic technologies cooperation funded by kolarctic CBC initiative of European Union(KO 4068).XRD analysis was performed at the Center of Microscopy and Nanotechnology(University of Oulu).The authors would like to thank Jarno Karvonen and Elisa Wirkkala for their assistance with the laboratory experiments.
文摘Wet granulation is a potential method to develop artificial aggregates.In this paper,the granulation of recycled alkali-activated slag powders with different particle size(d_(50) ranging between 12.9-127.7μm)distributions were investigated in order to find how these affect on the engineering properties of the artificial aggregates.Blast furnace slag was added as co-binder in 10-30 wt.%during the granulation process and to enhance the properties,especially mechanical strength.The results show that the particle size of the raw material significantly affects the engineering properties of the produced aggregates,such as the crushing force(19-131.8 N),bulk density,water absorption,porosity and microstructure of the granules.The results show that granulation is a promising method to recycle alkali-activated materials as lightweight aggregates to replace natural aggregates.
