The Research On The Nutrient Content Of The Liquidambar Formosana Forest System In Seasons

Liquidambar formosana is a fast-growing deciduous broad-leaved species in China's subtropical regions, strong adaptability and a fine timber species. Study the biomass, productivity and nutrition of Liquidambar formosana is helpful for providing the level of silviculture and generalizing the planting of Liquidambar formosana, there is important denotation it could promote sustainable development management of Liquidambar formosana forest.The results shows that the order of the content of macro-elements in leaves is spring>autumn>summer. The order of micro-elements contained in leaves as following:summer>spring>autumn,the same to the seasonal change of Mn in leaves,mostly because Mn has the biggest ratio in leaves. The seasonal change of nutrient elements in trunk is obviously, gradually increases from spring to winter, order as Ca>N>K>Mg>P. The seasonal change of micro-elements in trunk is not obvious, relative stable in each season, and have a minor change in autumn and winter. The maximum content of macro-elements in the big root of Liquidambar formosana happened in summer; average root has the contra trent of the content of macro-elements from spring to autumn; the content of macro-elements in small root increases fast from autumn. Big root and average root have the same trent in the content of micro-elements, both up and down like wave;the seasonal change of the content of micro-elements in small root is not obviously,and has a little reducing from autumn to winter.It shows that, the big root and average root of Liquidambar formosana can save micro-elements in the growing slowly season, and the small root only have the function of absorpt.The macro-elements of alive understorey in the Artifical forest of Liquidambar formosana show upward trend from spring to summer, and then show decreasing trend, especially in autumn and winter. There are almost vegetation and herbs in the understory of this forest, short life cycle, so the various elements of the seasonal change significantly.The litter storey in Artifical forest of Liquidambar formosana concentrated in the autumn and early winter, less in spring and summer, and most of which are fresh fallen leaves in many non-natural causes. Accordingly, the order of the quantity of micro-elements of litter storey in seasons is summer>autumn>winter>spring, and the content is the scope of 25.055～37.115 g-kg-1The content of the macro-elements in a layer's decrease from the beginning of the year and reach the nadir in autumn, and then start to rebound; b layer's of soil nutrient content changes in undee; c layer's of soil nutrients is in the upward trend, but the rate changes very little. With the depth of soil that less impact by the litter storey and the more stable soil nutrient content. With the impact in seasons of litter storey, the a layer's micro-elements changes in undee; the b layer's micro-elements shows upward trend in the year.The abilities of Liquidambar formosana to agglomerate the macro-elements are different, which orders as follow:Ca>Mg>N>P>K. Various organs of the macro-elements in soil accumulation ability to the order:bark> leaves> branches> root> wood. the abilities of Liquidambar formosana to agglomerate the micro-elements are Mn>Cu>Zn>Cd>Pb>Ni>Fe. Various organs of the micro-elements in soil acculation ability to the order:leaves>branches>root> bark> wood.