鼎湖山南亚热带常绿阔叶林植物营养元素含量分配格局研究

在鼎湖山南亚热带常绿阔叶林中，植物叶片营养元素含量为Ｎ ０．９４６％－２．５３５％，Ｐ ０．０３０－０．１２７％，Ｋ ０．６１４％－１．８３３％，Ｃａ ０．４４２％－１．９９５％，Ｍｇ ０．０２４％－０．１８８％。叶片各营养养元素间相关性较差，仅Ｐ与Ｍｇ及Ｍｇ与Ｋ之间存在显著的线性相关。叶片Ｎ元素平均含量在各层中的序列为：乔木Ⅲ〉乔木Ⅱ〉乔木Ⅰ〉灌木〉藤本〉草本；其它营养元素浓度随层次分配的规律性

DISTRIBUTION PATTERN OF NUTRIENT ELEMENTS IN PLANTS OF DINGHUSHAN LOWER SUBTROPICAL EVERGREEN BROAD-LEAVED FOREST

The investigation of plant nutrient contents in Dinghushan lower subtropical evergreen broad-leaved forest was carried out in August 1996. Sampling was made in Dinghushan Biosphere Reserve, Guangdong, from tree, shrub, liana and herb layers with 5-8 representative species each. It was shown that the nutrient contents in leaves of all plants were N 0.946% - 2.535%, P 0.030% - 0. 127%, K 0.614% - 1 .833%, Ca 0.442% - 1 .995% and Mg 0.024% - 0.188%. Average contents of nutrient elements in various organs and at different layers in the forest were varied. Average nutrient content of N was highest in leaves, and in descending order in barks, branches, root and stems, other elements: P in leaves > branches > roots > barks >stems; K in leaves > branches > barks > roots > stems, Ca in barks > leaves > branches > roots >stems, Mg in leaves > stems > roots > barks > branches. The distribution of elements in most plants was as follows f N>Ca >K>Mg>P in leaves, branches and roots, K>Ca >N>Mg >P in stems, and Ca >N>K>Mg >P in barks. The factors, especially P and Mg, possibly limiting the plant productivity in the area studied are discussed.