The Study On Population Spread Pattern In Eremochloa Ophiuroides Of Ya'an Wild

In order to study the population spread pattern in Eremochloa ophiuroides of Ya'an wild, the Ya'an wild centipedegrass was used by the experimentation material. In this study ,the different beginning density of planting stolons was used to simulate the disturbing adjacent plants. And the light grads and nutrient content grads was used to simulate the effect of resource heterogeneity. The study included the clonal plasticity to resource heterogeneity, the population spread in space scale and the population spread in time scale. The result indicate:1. There was segmental clonal plasticity to resource heterogeneity in Ya'an wild centipedegrass in the process of population spread. The clonal plasticity was distinctness in the biomass of centipedegrass plant to resource heterogeneity. And there was no response in effect to nutrient content grads of internode length and ramets amount. The stolon length had response in effect to nutrient content grads only in 100% light. The specific stolon weight had no response to nutrient content grads either. The clonal plasticity to light resource was the ordination and the clonal plasticity to nutrient was the subordination.2. The population spread in space scale was idiographic in changing of growth pattern and biomass accumulating rule. It was find out with study of fractal way to growth pattern, the centipedegrass had different fractal dimension and corresponding biomass accumulating rule. It reflected the diffent growth pattern and different space spread speciality; There was a bell curve of the velocity of the biomass acculating in the survey time. The fractal dimension was bigger than one and smaller than two. The ramets of centipedegrass was almost distributing in a plane. It was holding the planar space, but no full. The different fractal dimension reflected the holding degree to space. The bigger fractal dimension, the more holding space; the litter fractal dimension, the less holding space.The changing of fractal dimension was relational to the intensity of resource heterogeneity in the heterogeneity environment. The velocity of biomass acculating was increasing and the fractal dimension of plant was augmenting in the avail condition. The velocity of biomass acculating was decreasing and the fractal dimension of plant was minishing in the avail condition.The results showed that Eremochloa ophiuroides had a self-similarity growth process. The bigger(older) plant was the smaller(younger) plant with magnifying.So the clonal population of Eremochloa ophiuroides could adjust growth pattern according to the environment. This is a kind of adaptable ecological policy. On the one hand, it avoided to the best of one's abilities the interior competition and consume., on the other hand , it hold more resource to develop the clonal population to implement the population spread.3. The spread in time scale represented in the biomass and the module changing with the time going. It was find out with Logistic model that the biomass and the module amount of centipdegrass plant was fit for changing rule of Logistic model and the simulate effect was better. There was some amelioration to Logistic model for the characteristic for resource heterogeneity.The spread in time scale need the consistent of the modules of centipegrass plant in growth. The Logistic of the result curve show itself "S" type. This indicated that there was highly consistent in the survey time of the modules of the plant. So we thinked the natural growth of centipedegrass population plant depended on the consistent of the modules in growthing and developing. Only the interior consistent can bring the most advantage in exterior spread.There was some difference of the simulation curve in different environment. This indicated the plant growthing and developing had relation to environmeng. The different environment had different effect and maked difference in spread model one another. The centipedegrass population spread in time scale can be reflected by the dynamic of biomass and module amount. With the time gong, the stolon of centipedegrass lengthened, the ramets amount increased and the biomass augmented. In this way, the centipedegrass population achieved the population spread.4. Through the analysis in collectivity of population spread pattern we find that it was a dynamic process of sorbing resource in population. The resource was used to fill the least needing of plant in a measure. And the others was invested to the population spread. At the same time, the investing and sorbing resource strategy was effected by the resource heterogeneity environment. At the process of spread there was a dynamic balance between the sorbing and supplying in resource. The population had the largest spread velocity and benefit when the balance was exist between the outcome and income.