Based on the measurement of all individuals of population at different successional stage and following excavation of clones, the density and biomass dynamics of Hippophae rhamnoides L. subsp. sinensis population in M...Based on the measurement of all individuals of population at different successional stage and following excavation of clones, the density and biomass dynamics of Hippophae rhamnoides L. subsp. sinensis population in Mu Us sandland were analyzed with the methods of plots arranged with age and reverse age class addition(RAA). The main results were as follows:(1)The density of clone population increased with the population growth before 5-year-old. The population biomass accumulating also increased by Logistic equation in the period of age structure of population developed from increasing type to mid-decreasing type. Then they tended to be decrease. While the population density, population biomass augmented again with the emergence of gap regeneration, and the dominant status of H. rhamnoides L.subsp. sinensis population and the stability of the community were maintained.(2)The decrease process of density of daughter ramets population lagged behind that of mother ramets population, and the numerical ratio of daughter ramets population within the population gradually enlarged. As the population thinned, the composition of population changed from more clones with less daughter ramets to less clones with more daughter ramets and the genetic diversity of population reduced.(3)The prosperous stage of biomass accumulation appeared from 8-year-old to 16-year-old and its peak appeared at 12-year-old. And the relationship between the individual mean weight and population density could be expressed by the law of power-3/2 in the period of age structure of population developed from stable type to decreasing type.展开更多
文摘Based on the measurement of all individuals of population at different successional stage and following excavation of clones, the density and biomass dynamics of Hippophae rhamnoides L. subsp. sinensis population in Mu Us sandland were analyzed with the methods of plots arranged with age and reverse age class addition(RAA). The main results were as follows:(1)The density of clone population increased with the population growth before 5-year-old. The population biomass accumulating also increased by Logistic equation in the period of age structure of population developed from increasing type to mid-decreasing type. Then they tended to be decrease. While the population density, population biomass augmented again with the emergence of gap regeneration, and the dominant status of H. rhamnoides L.subsp. sinensis population and the stability of the community were maintained.(2)The decrease process of density of daughter ramets population lagged behind that of mother ramets population, and the numerical ratio of daughter ramets population within the population gradually enlarged. As the population thinned, the composition of population changed from more clones with less daughter ramets to less clones with more daughter ramets and the genetic diversity of population reduced.(3)The prosperous stage of biomass accumulation appeared from 8-year-old to 16-year-old and its peak appeared at 12-year-old. And the relationship between the individual mean weight and population density could be expressed by the law of power-3/2 in the period of age structure of population developed from stable type to decreasing type.
