Studies On Biology Of Arundinaria Fargesii Population

Arundinaria fargesii E.G.Camus belongs to Bambusoideae, Poaceae.It is a middle-mountain distributed middle-large amphipodial bamboo. It distributes mainly in the mountainous area of Dabashan and Qinling mountains, extending to Sichuan, Gansu, Shanxi, Chongqing, Hubei, Henan,six provinces. A. fargesii is one of the main food bamboos of Panda. It is fine material for paper making, and is widely used in weaving, as far as frame material in greenhouse. The bamboo shoots has high value of nutrition. The more higher the altitude,the later the emergence of bamboo shoots. At the altitude of 1900m, A. fargesii shoots emerge at about the end of April or the early of May. Mortality of the shoots is about 31.50%. The main reason is shortage of nutrition. Shoots which emerged asynchronously at the early of shooting time, end their growth almost synchronously. The process lasts about 70 days. Regression equation could forecast the growing process well.The amount of growing during the day(58.13%) is larger than that of during the night. The heigh-growth of A. fargesii clonal population presents a positive correlativity with the 5cm-depth soil temperature. The meristem at the rhizomatous tip of A. fargesii could keep its fissility for 20 years at least. Therefore the branching rhizome is hardly found. To such rhizome, however, it becomes easier to identify its ages because the length of the internodes varies regularly with aging in a year. In the favorable environment, the rhizome could produce about 13 nodes and stretch approximately 60cm one year. The contiguous grid quadrats have been applied to sampling for field data. The spatial pattern of A. fargesii clone population was the clumped distribution and the pattern scale was at 92.16m2, the relative intensity difference(RDD) was 3.89, which means the culms in the clumps are 3.89 times density of those in the interspace between clumps. The pattern grain was 38.17cm, which implies the mean distance between clumps is 38.17cm. The sympodial ramets hold the dominant status in the clone growth of the A. fargesii population. The strengthening trend of clumped distribution with ageing implies that the population was under a relatively stronge environmental pressure. The biomass allocations among culm, branch, leaf, root, rhizome, bamboo stump of A. fargesii were 55.6%, 9.51%, 3.40%, 2.06%, 8.70%, 20.77% respectively, while the aboveground biomass allocations of ramets from 1 to 5, 6 and 7, 8 and 9, 10 and more than 10 years old were 19.0%, 5.2%, 5.4%, 4.3%, 8.9%, 14.6%, 18.2%, 24.4% respectively. The underground biomass allocations among 0~20cm, 20~40cm and more deeper in depth of soil were 13.4%, 42.8%, 43.8% respectively. The stem weight of bamboos which were less than 3 years and over 8 age were lower than the standard stem weight, while which between 4 and 7 years were higher than the standard stem weight; With ageing: young----mature----old, the weight of leaf per ramet and the ratio of it to the weight of stem present the regularity: increasing----steady----declining.Analyzing based on the dynamic life table and survivorship curve, the results show that the clone individuals of A. fargesii died mainly at the time when the young bamboos just enter the rapid-growing period; A. fargesii population has considerable potencial for renovating. The using of static life table in the demography of A. fargesii population is not perfect, for the longevity of individuals and the difficulty to identify the exact ages of the old ones. Fertilization could increase the amount of the bamboo shoots and their survivors distinctly. However there is no distinct effect on the basic diameter of bamboo shoots and the height and diameter at breast height(DBH) of the new bamboos. The integration among ramets is evident, including the benefits and the costs of physiological integration. Local fertilization would improve fertilizing effects in the cultivation of A. fargesii forest. The density regulation at early spring has no evident effect on the the number of daughter ramets and their survivors in the same year, and to the height and DBH of the new bamboos, has the similar result. More amplification products and polymorphic loci was obtained from Foping population with 51 samples than Zhenba population with 72 samples. Foping population has more genetic diversity than Zhenba population. As far as these two populations, the genetic diversity exist mainly within populations(92.41%). Sampling from far apart each other and representative populations, 50 samples is enough for one population, could obtain the most plenty genetic diversity of A. fargesii, with the fewest samples. The results from 17 populations show that there are plenty genetic diversity within A. fargesii (Gst=0.5324).