Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negat...Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service （IN-DI-ESS） driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis （TS-DEA） to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1） Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2） Spearman＇s rank correlation test was performed to compare the overall effectiveness in two periods： stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.展开更多
Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging.For plants,trait variability across spatial dimensions is well documented.However,temporal dimensio...Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging.For plants,trait variability across spatial dimensions is well documented.However,temporal dimensions of trait variability are less well known,and may be influenced by seasonal differences in growing degree days(GDD),temperature and precipitation.Here,we aim to quantify intraspecific temporal variation in traits and the underlying drivers for four commonly occurring boreal plant species.Methods We sampled the elemental and stoichiometric traits(%C,%N,%P,C:N,C:P,N:P)of four common browse species'foliage across 2 years.Using a two-step approach,we first fitted generalized linear models(GzLM,n=24)to the species'elemental and stoichiometric traits,and tested if they varied across years.When we observed evidence for temporal variability,we fitted a second set of GzLMs(n=8)with temperature,productivity and moisture as explanatory variables.Important Findings We found no evidence of temporal variation for most of the elemental and stoichiometric traits of our four boreal plants,with two exceptions.Year was an important predictor for percent carbon across all four species(R^(2)=0.47-0.67)and for multiple elemental and stoichiometric traits in balsam fir(5/8,R2=0.29-0.67).Thus,variation in percent carbon was related to interannual differences,more so than nitrogen and phosphorus,which are limiting nutrients in the boreal forest.These results also indicate that year may explain more variation in conifers'stoichiometry than for deciduous plants due to life history differences.GDD was the most frequently occurring variable in the second round of models(8/8 times,R^(2)=0.21-0.41),suggesting that temperature is an important driver of temporal variation in these traits.展开更多
基金Under the auspices of Science and Technology Service Network Initiative Project of the Chinese Academy of Sciences(No.KFJ-EW-STS-002)
文摘Identifying the driving forces that cause changes in forest ecosystem services related to water conservation is essential for the design of interventions that could enhance positive impacts as well as minimizing negative impacts. In this study, we propose an assessment concept framework model for indirect-direct-ecosystem service （IN-DI-ESS） driving forces within this context and method for index construction that considers the selection of a robust and parsimonious variable set. Factor analysis was integrated into two-stage data envelopment analysis （TS-DEA） to determine the driving forces and their effects on water conservation services in forest ecosystems at the provincial scale in China. The results showed the following. 1） Ten indicators with factor scores more than 0.8 were selected as the minimum data set. Four indicators comprising population density, per capita gross domestic product, irrigation efficiency, and per capita food consumption were the indirect driving factors, and six indicators comprising precipitation, farmland into forestry or pasture, forest cover, habitat area, water footprint, and wood extraction were the direct driving forces. 2） Spearman＇s rank correlation test was performed to compare the overall effectiveness in two periods： stage 1 and stage 2. The calculated coefficients were 0.245, 0.136, and 0.579, respectively, whereas the tabulated value was 0.562. This indicates that the driving forces obviously differed in terms of their contribution to the overall effectiveness and they caused changes in water conservation services in different stages. In terms of the variations in different driving force effects in the years 2000 and 2010, the overall, stage 1, and stage 2 variances were 0.020, 0.065, and 0.079 in 2000, respectively, and 0.018, 0.063, and 0.071 in 2010. This also indicates that heterogeneous driving force effects were obvious in the process during the same period. Identifying the driving forces that affect service changes and evaluating their efficiency have significant policy implications for the management of forest ecosystem services. Advanced effectiveness measures for weak regions could be improved in an appropriate manner. In this study, we showed that factor analysis coupled with TS-DEA based on the IN-D1-ESS framework can increase the parsimony of driving force indicators, as well as interpreting the interactions among indirect and direct driving forces with forest ecosystem water conservation services, and reducing the uncertainty related to the internal consistency during data selection.
基金This research was funded by the Government of Newfoundland and Labrador Centre for Forest Science Innovation(CFSI)Memorial University of Newfoundland SEEDS funding to S.J.L.,E.V.W.and Y.F.W.+3 种基金Mitacs Accelerate Grant to Y.F.W.,S.J.L.and E.V.W.Canada Foundation for Innovation funding to Y.F.W.(13025)the Natural Sciences and Engineering Research Council of Canada(Discovery Grant RGPIN-2015-05799 to Y.F.W.)In-kind support was provided by Parks Canada-Terra Nova National Park and the CFSI,with thanks to Janet Feltham and Blair Adams.
文摘Aims Intraspecific variation in plant traits has important consequences for individual fitness and herbivore foraging.For plants,trait variability across spatial dimensions is well documented.However,temporal dimensions of trait variability are less well known,and may be influenced by seasonal differences in growing degree days(GDD),temperature and precipitation.Here,we aim to quantify intraspecific temporal variation in traits and the underlying drivers for four commonly occurring boreal plant species.Methods We sampled the elemental and stoichiometric traits(%C,%N,%P,C:N,C:P,N:P)of four common browse species'foliage across 2 years.Using a two-step approach,we first fitted generalized linear models(GzLM,n=24)to the species'elemental and stoichiometric traits,and tested if they varied across years.When we observed evidence for temporal variability,we fitted a second set of GzLMs(n=8)with temperature,productivity and moisture as explanatory variables.Important Findings We found no evidence of temporal variation for most of the elemental and stoichiometric traits of our four boreal plants,with two exceptions.Year was an important predictor for percent carbon across all four species(R^(2)=0.47-0.67)and for multiple elemental and stoichiometric traits in balsam fir(5/8,R2=0.29-0.67).Thus,variation in percent carbon was related to interannual differences,more so than nitrogen and phosphorus,which are limiting nutrients in the boreal forest.These results also indicate that year may explain more variation in conifers'stoichiometry than for deciduous plants due to life history differences.GDD was the most frequently occurring variable in the second round of models(8/8 times,R^(2)=0.21-0.41),suggesting that temperature is an important driver of temporal variation in these traits.
