Intraspecific Trait Variation And Effects On Population Stability Of Corispermum Lehmannianum

Intraspecific functional traits variation play an important role in the composition of populations and communities under the influence of environmental factors.Intraspecific trait variability is the fundamental contribution to the overall trait variability.In this study,the specie Corispermum lehmannianum,which was one of the dominat species in the Gurbantunggut Desert was been selected in order to clarify the contribution of intraspecific traits for population stability.The natural population of Corispermum lehmannianum was been investigated by setting research plots at different partitions of dune where it distribution is widly to get the data of traits.Then the distribution of the functional traits and its variation across environment gredients were described.Coefficient of variation(CV)of functional traits is the main way to quantify the intraspecific functional traits variation.The maintenance mechanism of the population was analyzed from the relationship between intraspecific functional trait variation and the stability of the population,analyzed the mechanism of the population persistent.The main results as follow:(1)The spatial distribution of the phenotypic characteristics was affected by the dune partitions.The height of the plant decreased and the crown of the plant increase from the the bottom to the top of the dune,and the root length increased with the elative altitude increase.(2)There was a common intraspecific trait variation(ITV)in the population.The coefficient of variation(CV)of plant height and canopy area increased first and then decreased during the growth,the coefficient of variation is greatest in the vegetative growth period.On the spatial scale,The CV under the shrubs' canopy areas was significantly higher than that in the bare area at the same dune partition(P<0.05),the value and CV of plant height and canopy area at the top of the dune were significantly different from that at others except germination period(P<0.05).(3)The ITV was influenced by the special environment,there were significantly differences in density and germination among dune partitions.The density and the germination were the smallest at the top of the dune.On the contrary,the density and the germination were the highest.The germination rate and death rate decreased with time.(4)The ITV plays a key role on the maintenance of population quantity dynamic.Intraspecific traits variation could reduce the population mortality,but could not affect the germination of population.The plant height first affected the population mortality,crown and plant height together affect the population mortality with the individual functional traits developement.But this effect does not affect direction of population changes.(5)The ITV has an important contribution to population stability.Its importance will be more extraordinary at high environmental stress.The coefficient of variation of population biomass decreased with the increase of coefficient of variation plant height as well as crown.The result highlight that the population stability of C.lehmannianum is strongly affected by microenvirorment such as different slope position and different canopy coverage in arid desert area,the intraspecific trait variation plays a key role at the adaptability to desert environment and contributes to the population persistent.