Background:Forests are an important sink for atmospheric carbon and could release that carbon upon deforestation and degradation.Knowing stand biomass dynamic of evergreen forests has become necessary to improve curre...Background:Forests are an important sink for atmospheric carbon and could release that carbon upon deforestation and degradation.Knowing stand biomass dynamic of evergreen forests has become necessary to improve current biomass production models.The different growth processes of managed forests compared to self-managed forests imply an adaptation of biomass prediction models.Methods:In this paper we model through three models the biomass growth of two tree species(Japanese cedar,Japanese cypress)at stand level whether they are managed or not(self-thinning).One of them is named self-thinned model which uses a specific self-thinning parameterαand adapted to self-managed forests and an other model is named thinned model adapted to managed forests.The latter is compared to a Mitscherlich model.The self-thinned model takes into account the light competition between trees relying on easily observable parameters(e.g.stand density).A Bayesian inference was carried out to determine parameters values according to a large database collected.Results:In managed forest,Bayesian inference results showed obviously a lack of identifiability of Mitscherlich model parameters and a strong evidence for the thinned model in comparison to Mitscherlich model.In self-thinning forest,the results of Bayesian inference are in accordance with the self-thinning 3/2 rule(α=1.4).Structural dependence between stand density and stand yield in self-thinned model allows to qualifying the expression of biological time as a function of physical time and better qualify growth and mortality rate.Relative mortality rate is 2.5 times more important than relative growth rate after about 40 years old.Stand density and stand yield can be expressed as function of biological time,showing that yield is independent of initial density.Conclusions:This paper addressed stand biomass dynamic models of evergreen forests in order to improve biomass growth dynamic assessment at regional scale relying on easily observable parameters.These models can be used to dynamically estimate forest biomass and more generally estimate the carbon balance and could contribute to a better understanding of climate change factors.展开更多
The silvicultural, chemical and biological measures were employed respectively to control the larva of Kumasia kumaso (Sugi) of Acidosasa edulis. :The silvicultural measures mainly included weeding & deeply buryin...The silvicultural, chemical and biological measures were employed respectively to control the larva of Kumasia kumaso (Sugi) of Acidosasa edulis. :The silvicultural measures mainly included weeding & deeply burying, weeding combined with burning , weeding & deeply burying combined with DDVP.And the biological measures included spraying with two kinds of B.t (made respectively in Jianou and Fuqing), Bacillust huringiensis (16000IU/mg), AcNPV etc.And the chemical measures included spraying with 80% DDVP E.C, 40% Omethoate E.C, Shachongguang or Lindane 1∶500× and 1∶1000× in 1999, and 17 5%Imidan E.C, 5%Cypermethrin E.C, 20%Fenpropathrin E.C, 20%Baibusi E.C 1∶800× and 1∶1500× in 2000. the results showed as follow: 1.In silvicultural measures, different treatments have no remarkable influence on the experiment results, but it can improve the hygienic condition. 2.In biological measures , different treatments have no remarkable influence on the experiment results. 3.In chemical measures, 1∶500 of Lindane was adapted to eliminate the larva in the mother shoots with the death ratio amounting to 91 10% What’smore, 20%Fenpropathrin E.C 1∶800×, 5%Cypermethrin E.C 1∶800×, 20%Baibusi E.C 1∶800× are also adapted to generalize in forestry with the death ratio amounting to 92 09%, 76 81%,75 74%respectively.展开更多
The annual ring width, density and shrinkage variation from pith to bark in Chinese fir (Cunninghamia lanceolata) and Boka sugi (Cryptomeria japonicd) were studied and compared. The results show that the ring width de...The annual ring width, density and shrinkage variation from pith to bark in Chinese fir (Cunninghamia lanceolata) and Boka sugi (Cryptomeria japonicd) were studied and compared. The results show that the ring width decreased sharply from pith to bark for Chinese fir. However, the ring width variation pattern for Boka sugi followed a different way, i.e., the ring width decreased to the fifth ring, increased to the tenth ring, decreased again to the fifteenth, and then increased to the twentieth, where it...展开更多
基金the State financial support managed by the Agence Nationale de la Recherche,allocated in“investissements d’Avenir”framework programme under reference AMORAD,ANR-11-RNSR-0002.
文摘Background:Forests are an important sink for atmospheric carbon and could release that carbon upon deforestation and degradation.Knowing stand biomass dynamic of evergreen forests has become necessary to improve current biomass production models.The different growth processes of managed forests compared to self-managed forests imply an adaptation of biomass prediction models.Methods:In this paper we model through three models the biomass growth of two tree species(Japanese cedar,Japanese cypress)at stand level whether they are managed or not(self-thinning).One of them is named self-thinned model which uses a specific self-thinning parameterαand adapted to self-managed forests and an other model is named thinned model adapted to managed forests.The latter is compared to a Mitscherlich model.The self-thinned model takes into account the light competition between trees relying on easily observable parameters(e.g.stand density).A Bayesian inference was carried out to determine parameters values according to a large database collected.Results:In managed forest,Bayesian inference results showed obviously a lack of identifiability of Mitscherlich model parameters and a strong evidence for the thinned model in comparison to Mitscherlich model.In self-thinning forest,the results of Bayesian inference are in accordance with the self-thinning 3/2 rule(α=1.4).Structural dependence between stand density and stand yield in self-thinned model allows to qualifying the expression of biological time as a function of physical time and better qualify growth and mortality rate.Relative mortality rate is 2.5 times more important than relative growth rate after about 40 years old.Stand density and stand yield can be expressed as function of biological time,showing that yield is independent of initial density.Conclusions:This paper addressed stand biomass dynamic models of evergreen forests in order to improve biomass growth dynamic assessment at regional scale relying on easily observable parameters.These models can be used to dynamically estimate forest biomass and more generally estimate the carbon balance and could contribute to a better understanding of climate change factors.
文摘The silvicultural, chemical and biological measures were employed respectively to control the larva of Kumasia kumaso (Sugi) of Acidosasa edulis. :The silvicultural measures mainly included weeding & deeply burying, weeding combined with burning , weeding & deeply burying combined with DDVP.And the biological measures included spraying with two kinds of B.t (made respectively in Jianou and Fuqing), Bacillust huringiensis (16000IU/mg), AcNPV etc.And the chemical measures included spraying with 80% DDVP E.C, 40% Omethoate E.C, Shachongguang or Lindane 1∶500× and 1∶1000× in 1999, and 17 5%Imidan E.C, 5%Cypermethrin E.C, 20%Fenpropathrin E.C, 20%Baibusi E.C 1∶800× and 1∶1500× in 2000. the results showed as follow: 1.In silvicultural measures, different treatments have no remarkable influence on the experiment results, but it can improve the hygienic condition. 2.In biological measures , different treatments have no remarkable influence on the experiment results. 3.In chemical measures, 1∶500 of Lindane was adapted to eliminate the larva in the mother shoots with the death ratio amounting to 91 10% What’smore, 20%Fenpropathrin E.C 1∶800×, 5%Cypermethrin E.C 1∶800×, 20%Baibusi E.C 1∶800× are also adapted to generalize in forestry with the death ratio amounting to 92 09%, 76 81%,75 74%respectively.
文摘The annual ring width, density and shrinkage variation from pith to bark in Chinese fir (Cunninghamia lanceolata) and Boka sugi (Cryptomeria japonicd) were studied and compared. The results show that the ring width decreased sharply from pith to bark for Chinese fir. However, the ring width variation pattern for Boka sugi followed a different way, i.e., the ring width decreased to the fifth ring, increased to the tenth ring, decreased again to the fifteenth, and then increased to the twentieth, where it...
