研究西南喀斯特峰丛洼地人工林、次生林、原生林3个不同森林类型的6个代表性植物群落C、N、P化学计量特征及其与土壤的关系.结果表明:不同森林类型植物和土壤C、N、P含量均存在显著差异.土壤c和N含量均为次生林最高,人工林最低,土壤P含量为人工林最高,原生林最低;植物c和P含量变化趋势为人工林〉原生林〉次生林,植物N含量为次生林最高,原生林最低.土壤C:P、N:P以及植物C:P均为原生林显著高于次生林和人工林,土壤C:N在不同森林类型间差异不显著;植物N:P为次生林最高,人工林最低,植物C:N为原生林〉人工林〉次生林.在不同森林类型中,乔木叶片N含量与P含量、C:N与C:P以及C:P与N:P之间均呈显著线性正相关,除了植物叶片C:N与N:P以及土壤C:N与N:P之间呈显著线性负相关外,植物和土壤的C、N、P、C:P均无显著相关性,说明土壤c、N、P供应量对乔木叶片C、N、P含量影响不大.
The stoichiometric properties of plant carbon (C), nitrogen (N) and phosphorus (P) and their relationships with soil were studied in six dominant plant communities in three forest types, i. e. , plantation forest, secondary forest and primary forest in depressions between karst hills, southwest China. The C, N and P contents of both plant and soil had significant differences among the different forest types. Soil C and N contents were the highest in the secondary forest and the lowest in the plantation forest. Soil P content was the highest in the plantation forest and the lowest in the primary forest. Plant C and P contents were in the order of plantation forest 〉 primary forest 〉 secondary forest, and plant N content was the highest in the plantation forest and the lowest in the primary forest. Soil N:P, C:P and plant C:P ratios were significantly higher in the primary forest than in the other two forest types. There were no significant difference for the soil C:N ratio among the three forest types. Plant N:P ratio was the highest in the secondary forest and the lowest in the plantation forest. Plant C : N ratio was in the order of primary forest 〉 plantation forest 〉 sec- ondary forest. There were significantly positive linear correlations between N and P contents, C:N and C:P ratios, C:P and N:P ratios of arbor leaves in the different forest types, and significant negative linear correlations between plant C : N and N : P ratios, and between soil C : N and N : P ratios. There were no significant correlations between plant and soil C, N, P contents and C:P ratio, suggesting that the supply of C, N and P from soil had little influence on plant C, N and P contents.