Ecological Strategies Of The Clonal Plant Potentilla Reptans L Var. Sericophylla

To study ecological strategies of the clonal plant Potentilla reptans L var sericophylla, five experiments were carried out.Experiment 1: The genet characters and the ramet population characters of the stoloniferous herb, Pottentila reptance were investigated in Larix gmelinii and Pinus tabulaeformis forest. The results showed that the characters of genet of P. retpans, such as petiole length, leaf area, number of stolon and the stolon length of genet were differed among these two habitats, where the characters of ramet population, such as ramet density and the aboveground biomass followed the opposite direction.Experiment 2: Fine-scale spatial pattern of P. reptans ramet population and its relations to spatial heterogeneity in soil resources was investigated. The results showed that P. reptans ramet population had a relatively coarse-scale spatial pattern, compared to spatial pattern of nine soil variables (soil organic matter, soil total nitrogen, soil total phosphate, soil water content, available phosphate, available potassium, NH4+, NO3- and pH). One of the reasons probably was that clonal plants were able to show strong plastic responses to fine-scale variability of soil resources and the interconnected ramets of clonal plants could share soil resources acquired through clonal integration. As the result, the local response was even out.Experiment 3: A reciprocal transplant-replant experiment was carried out to investigate clonal plasticity and local specialization of P. reptans selected from forest gap and forest understorey in Pinus tabulaeformis. The results show that there was no local specialization in the plasticity of characters related to clonal growth and clonal morphology. Clonal plasticity rather than local specialization was the main strategy of P. reptans in heterogeneous habitats.Experiment 4: The experiment consisted of two parts. The first one was carried out with eight levels of available nutrients (N, P, K) to investigate the clonal plasticity of P. reptans. in response to available nutrients. The biomass, number of stolons, number of ramets, the root/shoot ratio, root length, stolon internode length and pattern of biomass allocation (i.e) of the plants were measured. Most of them showedplasticity in response to available nutrients and the pattern of plasticity varied with the characteristics. Another experiment was carried out to investigate the plasticity of the plants at the different stages of development with the same treatment as the first experiment. The results showed that clonal plasticity increased with plant age. Biomass allocation showed the plasticity during the early stage of plant growth, where the total biomass of genet just responded to nutrient availability after a period of growth. The root length and specific root weight did not respond at the early stage of growth and showed plasticity in the late stage. The specific internode weight responded to nutrient availability. The leaf area showed the plasticity when the plants became older, where as specific leaf area responded to the availability nutrient at the early stage of plant growth.Experiments 5: Ramet-pairs of P. reptans from forest gap and forest understorey were subjected to unshading, shading and partial shading treatments in a pot experiment. Results showed that the genet biomass, total length of stolons, number of ramets, specific stolon weight, petiole length and specific petiole weight of the plant species under the shaded condition were smaller to those under the unshaded condition. The stolon internode length did not respond to the treatments. There was no difference in response of those characters between plants from the gap and the understorey. For the plants from forest gap habitat, the petiole length of ramets grown in the shaded patch and connected to different plant part in the unshaded patch was larger than that of ramets grown in the shaded patch and connected to different ramets in the same patch. Such modification of local response of ramet petiole to shading due to physiological integration was not ob...