Effect Of Soil Nutrient Patches On The Habitat Selection And Distribution Pattern Of Potentilla Anserine L. Population

The phenomenon of habitat heterogeneity is widespread in the nature.Clonal plants can overcome the adverse effects of habitat heterogeneity on its growth and reproduction produced by intraclonal division of labor and physiological integration and other ecological adaptation strategies.But now the effect of the size,distance,and distribution pattern of soil heterogeneity patches on growth and reproduction of clonal plants is not very clear.In this study,three kinds of soil nutrient patches traits as well as patch size,distance between neighboring patches,and patch patterns were simulated by fertilizing,while compared the difference of habitat selection,pattern type and size,the expantion ability and intraspecific competition of the P.anserina population in different soil nutrient patches,in order to provide a theoretical basis to analyze the mechanism of how habitat heterogeneity influence the growth strategy of clonal plant.The scientific questions were as follows:(1)Whether the population of P.anserina tend to place more aboveground biomass and ramets in high nutrient patch in different treatments of soil nutrient patches?(2)Whether the soil nutrient patch characteristics affect the distribution patterns of the P.anserine population?(3)Whether the capability along horizontal spatial expansion of P.anserine population is influenced by the soil nutrient patch characteristics?(4)Whether the soil nutrient patch characteristics affect the intraspecific competition of the plant population?The main conclusions were as follows:(1)Soil nutrient heterogeneity had a significant impact on the habitat selection of P.anserina population,under three treatment conditions,the plant population tend to place more aboveground biomass and ramets in higher nutrient patch.This phenomenon indicates that foraging behavior is an important measure of P.anserina when it response to the habitat heterogeneity.Moreover,the tendency of P.anserina population to select high nutrient patches was more obvious in the treatment of small scale,small distance and clumped patterns.(2)The scale,distance and distribution pattern of soil nutrient patches did not have a significant impact on the pattern of the P.anserina population.The patterns of the P.anserina population all showed an aggregated distribution under three treatments of soil nutrient heterogeneity.But the pattern intensity of P.anserina population was weakened with change of years and months.The distribution pattern of clonal plant populations may depend on a variety of factors,such as clonal growth characteristics,habitat heterogeneity and intraspecific competition which emerges with the increasing population density.(3)Soil nutrient heterogeneity increased the capability of spatial expansion of the P.anserina population.Habitat heterogeneity can promote clonal plant escaping the unfavorable habitats by an increase of spacer length or the growth rate of stolons.Moreover,the space expansion rate of P.anserina population presented decreasing trend with the scale and distance of patches increased.This showed that the capability of plants escaping adverse habitat and searching favorable habitats was stronger in the treatment of small scale and small distance.(4)Intraspecific competition intensity outside of the patches in different soil nutrient patches treatments were higher than the inside,but the difference was not significant.This phenomenon indicated that the relative scarcity of resources was the main reason which caused the more intense intraspecific competition outside of the patch.There occurred intraspecific competition in P.anserine population with age,and leaded to a decline in population density and ramet biomass.In summary,the size,distance,and distribution pattern of soil nutrient patch is an important environmental factor on habitat selection and distribution patterns of the P.anserine population.This suggests that we should particularly concerned about the impact of the differences in soil nutrient patch when we explained the adaptive mechanism of clonal plant populations in heterogeneity habitats.