黄土高原不同坡向中国沙棘种群生物量投资与分配

Biomass Allocation and Investment of Hippophae rhamnoides ssp.sinensis Populations Under Different Aspects of Slope in the Loess Plateau

以样地调查资料为依据,分析了黄土高原不同坡向种群生物量投资、分配的空间动态规律及其与种群存活、生长和繁殖能力之间的关系。结果表明:坡向通过改变土壤含水率制约中国沙棘种群的行为特征,而种群通过生物量投资与分配调节形成与土壤含水率相适应的种群行为特征。①土壤含水率是决定种群行为特征的主导因子,土壤含水率按照北坡、西坡、峁顶、东坡、南坡的顺序递减,种群的存活、生长及克隆繁殖能力也按此顺序递减。②种群及其构件的生物量投资随着土壤含水率的递减而递减,地上的生物量分配也随着土壤含水率的递减而递减,但地下生物量分配随着土壤含水率的递减而递增,即地下与地上生物量投资具有协同关系而生物量分配存在权衡作用。③种群生长量与地上、地下生物量投资及地上生物量分配呈正相关,而与地下生物量分配呈负相关;种群的克隆繁殖能力及潜力与萌蘖根、地上生物量投资及分配呈正相关,而与垂直根生物量分配呈负相关。根据这些研究结果推测,中国沙棘种群稳定性和克隆持久性由大到小的排列顺序为北坡、西坡、峁顶、东坡、南坡。

A survey was conducted to study the spatial dynamic characteristics of biomass investment and allocation of Hippophae rhamnoides ssp.sinensis populations under different slope aspects in the Loess Plateau based on the data of sample plots.And the relationships between biomass investment and allocation and population survival,growth and reproductive ability were analyzed.Results indicate that slope aspects restrict the behavioral characteristics of H.rhamnoides ssp.sinensis populations by changing soil moisture,while the populations form the adaptive ability to soil moisture by regulating population biomass investment and allocation.The dominant factor of population behavioral characteristics is soil moisture.Soil moisture in north slope is the highest,followed by west slope,hilly top,east slope and south slope in order.Population survival,growth and reproductive ability decrease in accordance with the above order.Investment and allocation of population and its modular biomass decrease with decreasing soil moistures.Aboveground biomass allocation decreases,but underground biomass allocation increases with decreasing soil moistures.It shows that there is a synergistic relationship between underground and aboveground biomass investment,while their biomass allocation exhibits a balance function.Population growth is positively correlated with aboveground and underground biomass investment and aboveground biomass allocation,but negatively correlated with underground biomass allocation.The ability and potential for clonal reproduction of populations are positively correlated with sprouting root and aboveground biomass investment and allocation,but negatively correlated with vertical root biomass allocation.These results suggest that the stability and clonal permanence of H.rhamnoides ssp.sinensis populations in north slope,west slope,hilly top,east slope,and south slope are arranged in descending order.