Ecological footprint(EF)accounting system is widely used in assessing environmental sustainability at various spatial scales.To improve the EF performance,a new EF calculation framework was established in this study,i...Ecological footprint(EF)accounting system is widely used in assessing environmental sustainability at various spatial scales.To improve the EF performance,a new EF calculation framework was established in this study,in which HWP is considered as carbon sinks and the model was then applied to the Yangtze River basin of China.Results showed that(1)carbon sink in the basin is about 2.99 Tg per year and it varies substantially across subbasins,which has a nonlinear relationship with net primary productivity;(2)available biocapacity calculated in the whole basin increases from 0.5068 to 0.5759 national ha(nha)per capita when incorporating the carbon sinks.In a few subbasins,the added biocapacity is even larger than the biocapacity estimated from the conventional approach;(3)the EF of the basin is 5.598 nha per capita and it is much larger than its biological carrying capacity(BC),indicating that ecological deficit is ubiquitous across the basin.If carbon sinks are considered,the ecological deficit would decrease by 3.2–14.3%for different regions in the basin.It is necessary to incorporate HWP and other potential terrestrial carbon sinks in the EF accounting,and more efforts are needed in improving carbon sink accuracy.展开更多
Two systems of additive equations were developed to predict aboveground stand level biomass in log products and harvest residue from routinely measured or predicted stand variables for Pinus radiata plantations in New...Two systems of additive equations were developed to predict aboveground stand level biomass in log products and harvest residue from routinely measured or predicted stand variables for Pinus radiata plantations in New South Wales,Australia.These plantations were managed under three thinning regimes or stand types before clear-felling at rotation age by cut-to-length harvesters to produce sawlogs and pulpwood.The residue material following a clear-fell operation mainly consisted of stumps,branches and treetops,short off-cut and waste sections due to stem deformity,defects,damage and breakage.One system of equations did not include dummy variables for stand types in the model specification and was intended for more general use in plantations where stand density management regimes were not the same as the stand types in our study.The other system that incorporated dummy variables was for stand type-specific applications.Both systems of equations were estimated using 61 plot-based estimates of biomass in commercial logs and residue components that were derived from systems of equations developed in situ for predicting the product and residue biomass of individual trees.To cater for all practical applications,two sets of parameters were estimated for each system of equations for predicting component and total aboveground stand biomass in fresh and dry weight respectively.The two sets of parameters for the system of equations without dummy variables were jointly estimated to improve statistical efficiency in parameter estimation.The predictive performances of the two systems of equations were benchmarked through a leave-one-plot-out cross validation procedure.They were generally superior to the performance of an alternative two-stage approach that combined an additive system for major components with an allocative system for sub-components.As using forest harvest residue biomass for bioenergy has increasingly become an integrated part of forestry,reliable estimates of product and residue biomass will assist harvest and management planning for clear-fell operations that integrate cut-to-length log production with residue harvesting.展开更多
基金This work was supported by National Natural Science Foundation of China(No.4170163131660169)+2 种基金Natural Foundation for Youth Scholars of Yunnan Province of China(Y0120160068)Joint Grant of Yunnan Provincial Science and Technology Department-Yunnan University Major Project(2018FY001-007)Yunnan Science and Technology Major Project(2018BC002).
文摘Ecological footprint(EF)accounting system is widely used in assessing environmental sustainability at various spatial scales.To improve the EF performance,a new EF calculation framework was established in this study,in which HWP is considered as carbon sinks and the model was then applied to the Yangtze River basin of China.Results showed that(1)carbon sink in the basin is about 2.99 Tg per year and it varies substantially across subbasins,which has a nonlinear relationship with net primary productivity;(2)available biocapacity calculated in the whole basin increases from 0.5068 to 0.5759 national ha(nha)per capita when incorporating the carbon sinks.In a few subbasins,the added biocapacity is even larger than the biocapacity estimated from the conventional approach;(3)the EF of the basin is 5.598 nha per capita and it is much larger than its biological carrying capacity(BC),indicating that ecological deficit is ubiquitous across the basin.If carbon sinks are considered,the ecological deficit would decrease by 3.2–14.3%for different regions in the basin.It is necessary to incorporate HWP and other potential terrestrial carbon sinks in the EF accounting,and more efforts are needed in improving carbon sink accuracy.
基金This study was supported by the Australian Government Department of Agriculture,Fisheries and Forestry,the Rural Industries Research and Development Corporation,and Forests NSW.
文摘Two systems of additive equations were developed to predict aboveground stand level biomass in log products and harvest residue from routinely measured or predicted stand variables for Pinus radiata plantations in New South Wales,Australia.These plantations were managed under three thinning regimes or stand types before clear-felling at rotation age by cut-to-length harvesters to produce sawlogs and pulpwood.The residue material following a clear-fell operation mainly consisted of stumps,branches and treetops,short off-cut and waste sections due to stem deformity,defects,damage and breakage.One system of equations did not include dummy variables for stand types in the model specification and was intended for more general use in plantations where stand density management regimes were not the same as the stand types in our study.The other system that incorporated dummy variables was for stand type-specific applications.Both systems of equations were estimated using 61 plot-based estimates of biomass in commercial logs and residue components that were derived from systems of equations developed in situ for predicting the product and residue biomass of individual trees.To cater for all practical applications,two sets of parameters were estimated for each system of equations for predicting component and total aboveground stand biomass in fresh and dry weight respectively.The two sets of parameters for the system of equations without dummy variables were jointly estimated to improve statistical efficiency in parameter estimation.The predictive performances of the two systems of equations were benchmarked through a leave-one-plot-out cross validation procedure.They were generally superior to the performance of an alternative two-stage approach that combined an additive system for major components with an allocative system for sub-components.As using forest harvest residue biomass for bioenergy has increasingly become an integrated part of forestry,reliable estimates of product and residue biomass will assist harvest and management planning for clear-fell operations that integrate cut-to-length log production with residue harvesting.
