As one of the main structural units in a building,a solid wood floor has significant strategic research value for low-carbon energy saving.Taking the production line of a solid larch wood floor as a case study,we asse...As one of the main structural units in a building,a solid wood floor has significant strategic research value for low-carbon energy saving.Taking the production line of a solid larch wood floor as a case study,we assessed the environmental load during production based upon a life cycle assessment.Using GaBi 6.0 software,we analyzed the associated carbon sequestration during floor production,with the initial planting density serving as the disturbance factor in a modular analysis.The results indicated that the cutting and finishing steps have relatively intense,negative influences on the environment,whereas transportation,ripping,and trimming do not.Additionally,recycling biomass waste has the potential to reduce greenhouse gas emissions.When the initial planting density was 3.0×3.0 m,carbon sequestration was relatively high.Although the emissions of freshwater pollutants,volatile organic compounds,and fine particulate matter（matter with a 2.5-μm diameter） were comparatively high,the reduction of greenhouse gas emissions was still excellent at this planting density.展开更多
C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m^-2) in May of 2004 and were harvested in the middle of Septembe...C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m^-2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem,and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area of C. acuminata seedlings all showed highest values at the planting density of 25 plants ·m^-2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100plants·m-2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m^-2. It is concluded that for the purpose to get raw materials with more CPT from C. acuminata, the optimal planting density of C. acuminata seedlings should be designed as 25 plants·m^-2.展开更多
Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spa...Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.展开更多
To improve the productivity of poplar planta- tions, a field experiment of split-plot design with four tree spacings and three poplar clones was established, and four soil enzyme activities and microbial biomass were ...To improve the productivity of poplar planta- tions, a field experiment of split-plot design with four tree spacings and three poplar clones was established, and four soil enzyme activities and microbial biomass were monitored in the trial. Soil enzyme activities, in most cases, were significantly higher in topsoil （0-10 cm） than in lower horizons （10-20 cm）. Soil cellulase, catalase and protease activities during the growing season were higher than during the non-growing season, while invertase activity followed the opposite trend. Soil invertase, cellulase and catalase activities varied by poplar clone but soil protease activity did not. Cellulase and protease activities in the plantation at 5 × 5 m spacing were significantly higher than in the other spacings. The highest catalase activity was recorded at 6 × 6 m spacing. At the same planting density, invertase activity was greater in square spacings than in rectangular spacings. Soil microbial biomass was also significantly affected by seedling spacing and poplar clone. The mean soil MBC was significantly lower in topsoil than in the lower horizon, while MBN showed the opposite pattern. Significantly positive correlations were observed among soil cellulase, protease and catalase activities （p 〈0.01）, whereas soil invertase activity was negatively and significantly correlated with cellulase, protease and catalase activities （p 〈 0.01）. Soil microbial biomass and enzyme activities were not correlated except for a significantly negative correlation between soil MBC and catalase activities. Variations in soil enzyme activity and microbial biomass in different poplar plantations suggest that genotype and planting spacing should be considered when modeling soil nutrient dynamics and managing for long-term site productivity.展开更多
Marilene Olga dos Santos Silva 1·Marcela Gomes da Silva 1·LTachi-branco(Tachigali vulgaris,L.F.Gomes da Silva&H.C.Lima)is a leguminous tree species native to the Amazon rainforest that has drawn attentio...Marilene Olga dos Santos Silva 1·Marcela Gomes da Silva 1·LTachi-branco(Tachigali vulgaris,L.F.Gomes da Silva&H.C.Lima)is a leguminous tree species native to the Amazon rainforest that has drawn attention for its remarkably fast growth,a required trait for biomass/bioenergy plantations.In evaluations of biomass production and wood properties of T.vulgaris planted in homogeneous plantations at diff erent spacings in the Amazonian state of Pará,Brazil,biomass of 7-year-old trees was quantifi ed for individual trees and the entire population.Wood was also sampled to assess properties relevant to bioenergy applications.The choice for spacing dimension for planting nonclonal T.vulgaris should consider whether the priority is greater productivity per tree,achieved with greater spacings(9.0 m 2 and 12.0 m 2),or productivity per area,achieved with closerina Bufalino 1·Maíra Reis de Assis 2·Delman de Almeida Goncalves 3·Paulo Fernando Trugilho 2·Thiago de Paula Protásio 4 spacings(6.0 m 2 and 7.5 m 2).Genetic variability of the T.vulgaris seed stand and/or high heritability of wood traits overcame the eff ect of diff erent spacing on all morphological,physical,chemical and energetic properties of T.vulgaris wood.This species has moderate basic density when cultivated at spacings larger than 6 m 2 and net heating value above 7.95 MJ/kg,which is suitable for bioenergy purposes.The high variation in wood properties within tree spacing is strongly indicative of great potential for genetic breeding.The fast growth and the suitable moderate wood basic density confi rm the outstanding potential of homogeneous plantations of T.vulgaris for providing wood for bioenergy.展开更多
We evaluated the effects of planting densities （500, 1,000, 1,500 and 2,000 trees.ha-1） on tree growth performance （diameter at base, diameter at breast height, and clear bole height） of two clones （RRIM 2020 and...We evaluated the effects of planting densities （500, 1,000, 1,500 and 2,000 trees.ha-1） on tree growth performance （diameter at base, diameter at breast height, and clear bole height） of two clones （RRIM 2020 and PRIM 2025） of nine years old plantations of rubber tree （Hevea brasiliensis Muell. Arg） in Malaysia. For the four planting densities of the two clones, basal area and diameter at breast height declined with increasing planting density. Clear bole heights were greatest at 1,500 trees.haland lowest at 500 trees.ha-1 for the clone RRIM 2020, and at 2,000 trees.ha-1and 500 trees.halfor clone RRIM 2025. We conclude that the ideal planting density is 2,000 trees.ha＂l for obtaining high volume of wood production and 500 trees-ha-1 for high wood quality.展开更多
基金supported by the Science and Technology Support Project for the Twelfth Five-year Grant in China(Grant No.2015BAD14B05)
文摘As one of the main structural units in a building,a solid wood floor has significant strategic research value for low-carbon energy saving.Taking the production line of a solid larch wood floor as a case study,we assessed the environmental load during production based upon a life cycle assessment.Using GaBi 6.0 software,we analyzed the associated carbon sequestration during floor production,with the initial planting density serving as the disturbance factor in a modular analysis.The results indicated that the cutting and finishing steps have relatively intense,negative influences on the environment,whereas transportation,ripping,and trimming do not.Additionally,recycling biomass waste has the potential to reduce greenhouse gas emissions.When the initial planting density was 3.0×3.0 m,carbon sequestration was relatively high.Although the emissions of freshwater pollutants,volatile organic compounds,and fine particulate matter（matter with a 2.5-μm diameter） were comparatively high,the reduction of greenhouse gas emissions was still excellent at this planting density.
基金This paper was supported by the National Natural Science Foundation of China (No.3970086) and Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11)
文摘C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m^-2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem,and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area of C. acuminata seedlings all showed highest values at the planting density of 25 plants ·m^-2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100plants·m-2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m^-2. It is concluded that for the purpose to get raw materials with more CPT from C. acuminata, the optimal planting density of C. acuminata seedlings should be designed as 25 plants·m^-2.
基金The work was supported by the National Key Research and Development Program of China(Grant Number 2016YFD0600402).
文摘Poplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.
基金funded by the National Key Technology R&D Program(2015BAD09B0203)the National Basic Research Program of China(973 Program,2012CB416904)by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘To improve the productivity of poplar planta- tions, a field experiment of split-plot design with four tree spacings and three poplar clones was established, and four soil enzyme activities and microbial biomass were monitored in the trial. Soil enzyme activities, in most cases, were significantly higher in topsoil （0-10 cm） than in lower horizons （10-20 cm）. Soil cellulase, catalase and protease activities during the growing season were higher than during the non-growing season, while invertase activity followed the opposite trend. Soil invertase, cellulase and catalase activities varied by poplar clone but soil protease activity did not. Cellulase and protease activities in the plantation at 5 × 5 m spacing were significantly higher than in the other spacings. The highest catalase activity was recorded at 6 × 6 m spacing. At the same planting density, invertase activity was greater in square spacings than in rectangular spacings. Soil microbial biomass was also significantly affected by seedling spacing and poplar clone. The mean soil MBC was significantly lower in topsoil than in the lower horizon, while MBN showed the opposite pattern. Significantly positive correlations were observed among soil cellulase, protease and catalase activities （p 〈0.01）, whereas soil invertase activity was negatively and significantly correlated with cellulase, protease and catalase activities （p 〈 0.01）. Soil microbial biomass and enzyme activities were not correlated except for a significantly negative correlation between soil MBC and catalase activities. Variations in soil enzyme activity and microbial biomass in different poplar plantations suggest that genotype and planting spacing should be considered when modeling soil nutrient dynamics and managing for long-term site productivity.
基金Agricultural Research Corporation of Amapá(EMBRAPA-Eastern Amazonia Unit),Amazonia Bank(BASA),Coordination for the Improvement of Higher Level Personnel(CAPES)the National Council for Scientifi c and Technological Development(CNPq),and Jari Celulose S.A.Company.
文摘Marilene Olga dos Santos Silva 1·Marcela Gomes da Silva 1·LTachi-branco(Tachigali vulgaris,L.F.Gomes da Silva&H.C.Lima)is a leguminous tree species native to the Amazon rainforest that has drawn attention for its remarkably fast growth,a required trait for biomass/bioenergy plantations.In evaluations of biomass production and wood properties of T.vulgaris planted in homogeneous plantations at diff erent spacings in the Amazonian state of Pará,Brazil,biomass of 7-year-old trees was quantifi ed for individual trees and the entire population.Wood was also sampled to assess properties relevant to bioenergy applications.The choice for spacing dimension for planting nonclonal T.vulgaris should consider whether the priority is greater productivity per tree,achieved with greater spacings(9.0 m 2 and 12.0 m 2),or productivity per area,achieved with closerina Bufalino 1·Maíra Reis de Assis 2·Delman de Almeida Goncalves 3·Paulo Fernando Trugilho 2·Thiago de Paula Protásio 4 spacings(6.0 m 2 and 7.5 m 2).Genetic variability of the T.vulgaris seed stand and/or high heritability of wood traits overcame the eff ect of diff erent spacing on all morphological,physical,chemical and energetic properties of T.vulgaris wood.This species has moderate basic density when cultivated at spacings larger than 6 m 2 and net heating value above 7.95 MJ/kg,which is suitable for bioenergy purposes.The high variation in wood properties within tree spacing is strongly indicative of great potential for genetic breeding.The fast growth and the suitable moderate wood basic density confi rm the outstanding potential of homogeneous plantations of T.vulgaris for providing wood for bioenergy.
文摘We evaluated the effects of planting densities （500, 1,000, 1,500 and 2,000 trees.ha-1） on tree growth performance （diameter at base, diameter at breast height, and clear bole height） of two clones （RRIM 2020 and PRIM 2025） of nine years old plantations of rubber tree （Hevea brasiliensis Muell. Arg） in Malaysia. For the four planting densities of the two clones, basal area and diameter at breast height declined with increasing planting density. Clear bole heights were greatest at 1,500 trees.haland lowest at 500 trees.ha-1 for the clone RRIM 2020, and at 2,000 trees.ha-1and 500 trees.halfor clone RRIM 2025. We conclude that the ideal planting density is 2,000 trees.ha＂l for obtaining high volume of wood production and 500 trees-ha-1 for high wood quality.
