Dynamic Of Potentilla Flagellaris Clonal Population In Songnen Grassland

Modular dynamics and reproduction strategy of clonal population play important role in population ecology research. Potentilla flagellaris clonal population naturally growing was studied in the Songnen grassland. By the method of large random samples, it was observed that the modular seasonal dynamics of total stolon length, spacer length and petiole length, and distribution pattern of spacer length, and compared with the numbers of mother ramets, daughter ramets and single ramets as well as the yearly dynamics of total biomass in 4 years(2003,2005,2006,2007). Furthermore, the correlation between population quantitative characteristics and the community were analyzed. The main conclusions are as follows:(1)The total stolon length of P. flagellaris population decreased gradually in growing seasons. The elongation of stolons and space extension as well as the formation of"latent ramet"mainly completed in the early growing season. The petiole length increased gradually with the growth, and the maximum in July. The tendencies of petiole length may be influenced by light conditions in community. The average spacer lengths presented different distributing in different years. In 2006, it presented the"short-long-short"distributed pattern. In 2007, the"short-long"distributed pattern was presented. The distributed pattern of spacer length possibly contained complex information about the population behavior of looking for food, daughter ramet estabilishment and the spatial expansion strategy.(2)During the growing seasons, the numbers of mother ramets, daughter ramets, single ramets and biomass had changed in different extent. The distributed differences of P. flagellaris indicated that mother ramets, daughter ramets, single ramets in the population took on respective functions. There was a certain change of P. flagellaris in the mother ramets, daughter ramets and single ramets, in which daughter ramets had an extremely significance. This kind of large scale changed among years may be related to the interspecies interactions in the community.(3)The P. flagellaris had a difference on population characteristics, and its correlative factors among months and years are different. The total length of stolon positively correlated (P<0.05) with density in 2006, and the single ramets had an obvious positive correlation (P<0.05) with coverage in July. The number and height of mother ramets presented obviously negative correlation(P<0.05), extreme obviously positive (P<0.01) and extreme negative correlations (P<0.01) in May, June and July in 2007respectively. So we predicted that the number of the mother ramets may have a fittest population height. It is only May, daughter ramets negatively correlated (P<0.05) with density, and the total biomass and stolon presented correlation (P<0.05) and extreme correlation (P<0.01) with coverage respectively. In June, stolon and coverage had an obvious positive correlation. The interspecific relationship and the growth rule of P. flagellaris maybe the main reason of the correlation.(4)P. flagellaris has a high breed fertility ability but its survival ratio was low. The reasons are not clear now.