海南不同生活型植物叶片和根系C、N、P化学计量特征

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(Premnaligustroides)、彩叶朱槿(Hibiscusrosa-sinensis)和厚叶榕(Ficusmicrocarpavar.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。

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

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.