海南通什低质低效次生林林下植被多样性与土壤养分特征——以加勒比松林为例

为了探讨海南省低质低效林高效栽培技术，为海南省低质低效林改造奠定基础，采用样方调查及取样分析方法，研究了海南省国营通什林场（109o31′E，18o46′N）低质低效加勒比松次生林林下植被物种多样性、生物量及其土壤理化性质，并探讨了它们之间的相关性。结果表明，灌木层植物丰富度、多样性指数均高于草本层，但均匀度指数却低于草本层；林下植被生物量总体表现为灌木层大于草本层；土壤全N的含量在1.15~1.78 g/kg之间，0~20 cm土层的全N含量与20~40 cm土层及40~60 cm土层间差异性显著。40~60 cm土层的有效P含量与其余2层呈显著差异。0~20 cm土层速效K含量与其余2层差异性显著。从试验结果可以看出，海南省低质低效林土壤养分较为贫瘠。林下物种多样性指数与土壤全N、全P、全K、速效K含量之间具有显著正相关，但与容重、pH值相关性并不显著。生物量与土壤的理化性状相关性不大。

Undergrowth Vegetation Species Diversity and Soil Fertility of Low-quality and Low-effect Secondary Forest in Tongshi of Hainan: A Case Study of Pinus caribaea Morelet

In order to discuss the efficient cultivation technique of low-quality and low-effect secondary forest of Hainan Province, lay the foundation for the renovation of the low-quality and low-effect secondary forest of Hainan. The undergrowth vegetation diversity, biomass and its soil physical and chemical properties of inferiority and inefficient Pinus caribaea Morelet secondary forest in state forest Tongshi farm （109°31 ＇ E, 18° 46 ＇ N） in HaiNan Province were researched, and the correlation between them was studied by the method of quadrates investigation and sampling analysis. The results showed that the plant richness and diversity indices of shrub layer were higher than the herb layer, but the evenness index was lower than the herb layer; the general result of undergrowth vegetation biomass was that shrub layer was more than grass layer. The content of soil total N was between 1.15-1.78 g/kg, where there were significant differences in the content of total N among in the 0-20 cm soil, 20-40 cm soil and 40-60 cm soil. It was showed significant differences in the content of available P between the 40-60 cm soil and the other two. It was showed significant differences in the content of quick K between the 0-20 cm soil and the other two. From the experiment results, it was concluded that the soil nutrient was poor. The diversity indices of undergrowth species had significant positive correlation relationship with the content of soil total N, P, K and quick K, but no obvious correlation relationship with the bulk density, pH value, and little correlation with soil physical and chemical properties.