The Study On Morphological Plasticity Of Aeluropus Littoralis Var. Sinensis Population In Songnen Plain

The study of morphological plasticity is presently the important field of clonal plant population ecology. By sampling large random trials, the characters of modulars and ramets of natural A. littoralis var. sinensis population which grows in Leymus chinensis meadow in sourthern of Songnen plain have been conducted and the correlations between the traits of it and pH, electrical conductivity, organic matter, total nitrogen, total phosphorous, total potassium of soil have been analyzed by the way of simple correlation and partial correlation, at the same time, the responses of morphological plasticity of it to six variable nitrogen treats have been compared, also the law by which the morphological traits of it changed in 2003 and in 2004 has been explored. The results have been showed as following: In natural habitats, there is significant negative correlation between stolon length and pH of soil(P<0.05), the same correlation between the ramet height and total phosphorous, pH of soil; while the correlation between the ramet biomass, the total biomass of A. litoralis var. sinensis and total potassium of it is significantly positive correlation(P<0.05); other factors, such as the electrical conductivity, organic matter, total nitrogen of soil have no correlations with traits of it(P>0.05). From this, it implied that the dominant factors of the six measured soil factors that affect the morphological plasticity are the pH, total phosphorous, total potassium of soil. That is to say, It is the small scale heterogeneity of the pH, total phosphorous, total potassium of soil in A. littoralis var. sinensis single dominant community that affect the morphological plasticity. In natural habitats, there is very significant correlation between the vegetative growth related traits and the measured biomasses of A. littoralis var. sinensis(P<0.01), the correlations between the stolon length and the quantity and the biomasses of vegetative ramets are significant(P<0.05), the correlations between total biomass and the quantity and the biomasses of sexual plants are significant(P<0.05), and the biomass of vegetative ramet and the biomass of sexual ramet also has significant correlation(P<0.05). It indicated that vegetative growth is of very important value during the process of biomass accumulation. In natural habitats, the number of node, ramet height, the biomass of spacer and the biomass of ramet of stolon have significant variance in 2003 and in 2004(P<0.01), but the spacer length has no variance in 2003 and in 2004(P>0.05), the biomass of ramet and the biomass of spacer have approximately the same ratios in total biomass. Under the condition of nitrogen treats, the number of shoot and branch intensity have no variance in variable treats of different months; that is to say, they have no responses to nitrogen treats. While the stolon length is more shorter with the higher of nitrogen treats, which indicates that stolon length responses to nitrogen; For ramet height, it has very significant variance in variable treats of different months, and it is high both on poor nitrogen treats and rich nitrogen treats, while it is short on median nitrogen treats. On variable nitrogen treats, the number of survival ramets has variance in the end of growth season(P<0.05), but the quantity of vegetative ramet and the quantity of sexual ramet in variable treats have no variance(P>0.05). In the end of growth season, the biomass of parent ramet has the ratios of total biomass above 70%, which indicates that fertilizing in the prophase of growth season will boost the growth of parent ramet and comparatively reduce the cost on reproduction. It has been used as an ecological strategy to heterogeneity in space and in time for A. littoralis var. sinensis.