Tsuga lorgibracteata\% is one of the rare gymnosperms and endemic to China. With the changes in environment and ecosystems, the total number of individuals has decreased rapidly and it is considered an endangered plan...Tsuga lorgibracteata\% is one of the rare gymnosperms and endemic to China. With the changes in environment and ecosystems, the total number of individuals has decreased rapidly and it is considered an endangered plant on the brink of extinction. This paper dealt with the growth dynamics of dominance of rare and endangered \%Tsuga lorgibracteata\% population based on the growth models, which were four limited space growth models for population. Compared with the fitting results of four models, the best growth model was selected to express the growth dynamics of dominance for \%Tsuga lorgibracteata\% population, which was \%s\%=exp (-0 046 804 ln\+2(1+108.386 5 e\+\{-0.594 42\%t\%\})-0.873 71 ln(1+108.386 5 e\+\{-0.594 42\%t\%\})+3.655 44). Then the environmental capacity of dominance of \%Tsuga lorgibracteata\% population was calculated. It was 38.684 7 m\+2\5hm\+\{-2\}. And the simulated result of dominance showed that when the diameter at breast height was about 40 cm, the population growth of dominance would be highest, which would provide a theoretical basis for the protection and management of \%Tsuga lorgibracteata.展开更多
The density effect of rare and endangered Tsuga longibracteata population was analyzed by the theoretical model describing the whole density change process of plant population, i.e. N =exp( a ln 2S+b ln S+c) , where N...The density effect of rare and endangered Tsuga longibracteata population was analyzed by the theoretical model describing the whole density change process of plant population, i.e. N =exp( a ln 2S+b ln S+c) , where N and S represent population density and mean basal area of T.longibracteata at breast height respectively, and a, b, c are parameters. Then, the authors proposed a density effect model considering the effect of different site and associated species on density regulation of T.longibracteata, which was described as N= exp (-0 42426H 0 55323 ln 2S-5 60238H 0 25191 ln S-6 75209H 0 10815 )+ exp (0 20437 ln 2S′-0 095858 ln S′-0 14548), where H and S′ represented mean height of dominant trees and mean basal area of associated species at breast height. The simulated result showed that the model fitted well observed data from T. longibracteata population. Therefore it is very useful in practice, which will provide a scientific basis for density management of T. longibracteata population.展开更多
文摘Tsuga lorgibracteata\% is one of the rare gymnosperms and endemic to China. With the changes in environment and ecosystems, the total number of individuals has decreased rapidly and it is considered an endangered plant on the brink of extinction. This paper dealt with the growth dynamics of dominance of rare and endangered \%Tsuga lorgibracteata\% population based on the growth models, which were four limited space growth models for population. Compared with the fitting results of four models, the best growth model was selected to express the growth dynamics of dominance for \%Tsuga lorgibracteata\% population, which was \%s\%=exp (-0 046 804 ln\+2(1+108.386 5 e\+\{-0.594 42\%t\%\})-0.873 71 ln(1+108.386 5 e\+\{-0.594 42\%t\%\})+3.655 44). Then the environmental capacity of dominance of \%Tsuga lorgibracteata\% population was calculated. It was 38.684 7 m\+2\5hm\+\{-2\}. And the simulated result of dominance showed that when the diameter at breast height was about 40 cm, the population growth of dominance would be highest, which would provide a theoretical basis for the protection and management of \%Tsuga lorgibracteata.
文摘The density effect of rare and endangered Tsuga longibracteata population was analyzed by the theoretical model describing the whole density change process of plant population, i.e. N =exp( a ln 2S+b ln S+c) , where N and S represent population density and mean basal area of T.longibracteata at breast height respectively, and a, b, c are parameters. Then, the authors proposed a density effect model considering the effect of different site and associated species on density regulation of T.longibracteata, which was described as N= exp (-0 42426H 0 55323 ln 2S-5 60238H 0 25191 ln S-6 75209H 0 10815 )+ exp (0 20437 ln 2S′-0 095858 ln S′-0 14548), where H and S′ represented mean height of dominant trees and mean basal area of associated species at breast height. The simulated result showed that the model fitted well observed data from T. longibracteata population. Therefore it is very useful in practice, which will provide a scientific basis for density management of T. longibracteata population.
