| Keteleeria fortunei, belonging to family Pinaceae, is a tall arbor, a sun-loving tree with thick and developed roots, and wide adaptability to soil. It has developed cortex and adapts to drought environment. The tree height and DBH reach 30 meters and 1 meter, respectively. The trunk is upright. The wood color is yellowish-brown, the wood is heavy, water-tolerant, and anti-caustic. The texture is straight. It is a precious timber tree species used for architecture, bridge, cabin, furniture, farm tools and artificial board surface. The tree is elegant with density branches and leaf, which documents its high value in greening. It is a relict tree species in China. The natural population of Keteleeria is rare and endangered because of the natural environment, biological characteristics itself and the human felling, thus it is on the list of the important protected tree species of Fujian province and China. The study on K. fortunei can protect the precious germplasm and promote the artificial utility.The productivity of 50-year-old plantation of K. fortunei was studied in Hunei, Daping village, Taocheng town, Yongchun county, Fujian province. The main purposes of this study are as the followings:(1) The growth law of K. fortunei. The growth law of K. fortunei described based on the analysis tree height, DBH and individual volume, which provides scientific basis for the management of the plantation.(2) The biomass spatial distribution law of K. fortunei. The productivity of K. fortunei was understood based on the determination on its biomass and the study on the biomass spatial distribution law, which provides scientific data for reasonable protection, management and utility of K. fortunei resources, and for construction of rapid-growing and high-yielded plantation population.(3) The nutrient element accumulation and allocation pattern of K. fortunei. The nutrient element accumulation and allocation pattern was studied based on the determination on the nutrient elements in different organs, such as leaves, branches, barks, roots, and so on, which provides theory basis for the scientific management and fertilization for K. fortunei.The potential productivity, growth and development law and nutrient allocation law of K. fortunei were studied based on the biomass, growth and development, and nutrient standing stock, which provide the scientific basis and references for the development of the plantation.The main purposes of this study are as the followings:(1) The current annual increment of tree height fluctuated. The average increment change law was similar to current annual increment, but its rangeability was small. There were two rapid growing phases, the 5th-16 th years and 20 th – 24 th years, respectively. During the period, the methods of tending, water and fertilizer management, and scientific intermediating cuttings could be performed to promote the tree growing. The former 26 years was the period for K. fortunei to grow. Two peaks of the current annual increment occurred on the 12 nd year and 22 nd year. During this stage, based on the control on the stand density, the management of nutrient and water, moderate intermediate cuttings, and increasing the intermediate cuttings in good site conditions, the K. fortunei plantation could be cultivated for the purpose of big-diameter timber. For K. fortunei the former 50 years was the rapid growing stage. To improve growth environment for the stand, the intermediate cuttings based on stand management purpose and practical situation should be considered so as to obtain largest volume.(2) The growth process of K. fortunei was matched using different models. For K. fortunei the Weibull model mostly matched the height increment, and the correlation index and residual sum of squares were 0.9988 and 1.482676, respectively. For K. fortunei the Korf model mostly matched the volume increment, and the correlation index and residual sum of squares were 0.9991 and 0.000662, respectively.(3) There was difference among each organ above ground in water content, from high to low: leaf>trunk>branch>bark. There was difference among each diameter root underground in water content, and the water content increased first then decreased while the root diameter decreased. The water content was the highest, 63.18%, at the diameter 10-15 cm. The water content was the lowest, 45.83%, at the diameter 0-1 cm.(4) The biomass' vertical distribution law: Taking 2 cm as one section, each section biomass increased first then decreased while the section altitude increased. The biomass allocation of different organ: trunk>root>bark>branch>leaf. The total biomass was 699.57 t·hm-2. The biomass above ground was 566.62 t·hm-2, accounting for 80.99% of the total biomass. The biomass underground was 132.96 t·hm-2, accounting for 19.01% of the total biomass. The net productivity was 13.99 t·hm-2·a-1. The biomass of understorey vegetation layer was 11.22 t·hm-2. The litter layer biomass was 5.35 t·hm-2.(5) The nutrient accumulation vertical distribution law: Taking 2 cm as one section, the nutrient accumulation of each section nutrient and bark decreased while the section altitude increased. Whereas the nutrient accumulation of each section branches and leaves increased first then decreased.(6) The standing stock of the nutrient: the nutrient standing stock of the arbor layer reached the highest, 3949.02 kg·hm-2. The next was the vegetation layer, 3949.02 kg·hm-2. The litter layer was the lowest, 2659.41 kg·hm-2 only. The total nutrient standing stock: trunk>root>bark>branch>leaf, matching the biomass allocation law, which indicated the biomass allocation played the leading role in the stand nutrient standing stock allocation. From the view of different element standing stock of arbor layer, C was the highest, and P was the lowest. |
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