海南不同生活型植物叶片和根系C、N、P化学计量特征

C, N, and P Concentrations and Their Stoichiometry of Leaves and Roots with Different Life Forms in Hainan Province

摘要:

为了解热带地区植物的营养元素利用策略，对海南3个生活型的9种植物的叶片和根系碳（C）、氮（N）、磷（P）含量及化学计量比进行分析，包括车前（Plantago asiatica）、蒭雷草（Thuarea involuta）、木耳菜（Psidium guajava）、桑（Morus alba）、臭黄荆（Premna ligustroides）、彩叶朱槿（Hibiscus rosa-sinensis）和厚叶榕（Ficus microcarpa var.crassifolia）、海岸桐（Guettarda speciosa）和番石榴（Psidium guajava）。结果表明，不同生活型间的元素含量和化学计量比没有显著差异；叶片C、N、P含量高于根系，叶片的C、N含量与根系的呈显著正相关，P含量与根系的呈显著负相关。C：P与N：P低于全国和全球尺度，说明该地区植物具有较高的生长速率。小于14的N：P表明海南热带植物的生长主要受N限制。这揭示了海南热带植物不同生活型的营养元素利用策略相似，虽然受N限制，海南的植物仍具有较高的N、P固持能力和生长速率。

Abstract:

In order to understand the resource-use strategies of nutrient elements of plants in tropical region, the C, N, and P concentrations and their stoichiometry of 9 species with three life forms in Hainan were studied. The results showed that there were not significant differences in C, N, and P concentrations and stoichiometric ratios among different life forms. The C, N, and P concentrations of leaves were higher than those of roots. The C and N concentration of leaves was positively related with that of roots, but the P concentration of leaves was negatively related with that of roots. The ratios of C:P and N:P were relatively smaller than that at national and global scale, indicating that plants had high growth rate in this region. N:P ratio less than 14 showed that plant growth were limited by N in Hainan. Therefore, it was suggested that the plants with different life forms in Hainan showed similar resource-use strategies, although N limitation occurred, the plants had high growth rate and retaining ability of N and P.