| Paulownia fortune1, with rapid growth, excellent quality and great economic value are the most widely distributed species of Paulownia. According to the investigation of height and DBH in young period, the observation of the photosynthetic characteristics and the research on the dynamic change of the mineral element in the leaves, the text finally tell us the growth characteristics of different provenances of Paulownia fortune!. The result is as following:1. The tree height and DBH growing characteristics in young period of different provenances of Paulownia fortunei are different. The tree height which grows fastest is the provenance from Gan Zhou, Jiang Xi province. The DBH that grows fastest is from Ji ’an, Jiang Xi province. The slowest of both height and DBH is the provenance from Wu Zhou, Guang Xi province. Different provenance of tree height and DBH has something to do with geographic origin.2. The Paulownia fortunei planted in the gentle terrain grows more rapidly and these planted in steep slope grow slower. Tree height and the latitude, longitude of geography are negatively related. While DBH shows no obvious correlation. We can divide the Paulownia fortunei into three areas according to the cluster analysis on the tree height of different provenances and the source of different geographical origin. They are fast-growing species region in southern Jiang Xi province, medium-growing species in the central subtropics and relatively slow-growing species in southern Guang Xi province, he Pmax of different provenances of Paulownia fortunei is between20.71and32.73μmol-m-2-s-1. The average value is27.22μmol-m-2-s-1. The minimum value is the provenance from Long Quan, Zhe Jiang province. The maximum value is from Gan Zhou, Jiang Xi province. The LCP and LSP of different provenance of Paulownia fortune are not the same. The LCP is between17and67umol i·m-2-s-1. The maximum value is the provenance of Zhen Ning, Gui Zhou province and the minimum value is from Li Shui, Zhe Jiang province. Besides, the LSP is between639-1099μmol-m-2-s-1. The maximum is from Ji’an, Jiang Xi province. The minimum is from Wu Zhou, Guang Xi province. There are some correlation between photosynthetic indexes and mass growth of difference provenances. There exists high correlation of tree height, DBH and the LCP, and low correlation in BBH, tree height and LSP, which illustrates the provenance of high LSP and low LCP is better for the biomass accumulation of Paulownia fortunei.3. By late April, three main elements—N, P, K, in the leaves of Paulownia fortunei are transported into the vigorous growing areas like tender leaves, which can guarantee the growth of the plants and high nutrition content in the leaves. By May, the speed of leaf-growth is greater than that of dry matter accumulation, which dilutes the content of nutrient in the leaves. At the same time, the content of N, P, K in the leaves will falls sharply than that in April. When summer comes, the N, P, K in the soil will be absorbed by the plants easily. The content of N, P, K in the leaves will increase too. Then trees will appear a second growing peak. In autumn, the leaves will be aging gradually. The weight of the leaves will fall and the content of N, P, K will increase as well. In the growing season, the content of Calcium (Ca) in the leaves will reduce in rolling trend; Ferrum (Fe) in "W" shape, and the content of element Zinc (Zn)will take on an overall downward trend, but it will rise at the beginning of the defoliation. The content of element Magnesium(Me) will increase at the beginning and decrease then which will be stable after summer. The content of Copper (Cu) will also increase at the beginning and decrease later, and change in a rolling trend. The content of Manganese (Mn) also takes on a rolling trend. Besides, the content of Manganese (Mn) in different provenance is different in Spring and this dynamic change will consistent later. |
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