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

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

摘要:

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%,P0.030%-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不甚明显,但总趋势为乔木层植物略低于其它层植物。不同营养元素平均含量在各器官中的大小排列顺序为:N叶＞皮＞枝＞根＞干；P叶＞枝＞根＞皮＞干；K叶＞枝＞皮＞根＞干；Ca皮＞叶＞枝＞根＞干；Mg叶＞根＞皮＞枝＞干.大部分植物在同一器官中各营养元素平均含量序列为:叶、枝和根中均为N＞Ca＞K＞Mg＞P；干K＞Ca＞N＞Mg＞P；皮Ca＞N＞K＞Mg＞P,对元素含量分配格局分析表明,P和Mg很可能是限制南亚热带常绿阔叶林植物生产力的最重要营养元素。

Abstract:

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，branchcs，root and stems；other elements：P in leaves > branches > roots > barks >stems；K in leaves > branches > barks > roots > stems；Ca in barks > leayes > branches > roots > stems；Mg in leaves > stems > roots > barks > branches．The distribution of elements in most plants was as follows： 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．