Through the investigation of 18 plant plots at south Gansu Province sub-alpine meadow habitats,this paper aims to study plant leaves N,P content and their stoichiometry characteristics,and combined with the analysis of soil nutrients,to understand relationship between plant leaves N,P content and their stoichiometry characteristics and soil N P content,soil organic carbon,soil water content and soil N∶ P ratio.The results showed that plant leaf N content at different slopes varied between 4.46 mg·g-1 and 26.59 mg·g-1,with an average of 16.24 mg·g-1 ; P content was in the range of 0.71 ～ 1.98 mg·g-1,with an average of 1.37 mg·g-1 ; N∶P ratio changed between 6.43 and 17.75,and average was 11.60.The leaf N content and N ∶ P ratio on a different slope gradient had no significant difference (P ＞ 0.05),while the leaf P content was significantly different in different habitats.The inter-species differences of leaf N,P content and N∶ P ratios were significant (P ＜ 0.05),while interaction effect between species and habitats on leaf N and P content and N ∶ P ratio was not significant.Based on the evaluation of N ∶ P ratio threshold of limiting factor,plant growth in this area was affected by N,which also indicates adaptation of plants in that region to their habitat.%通过对甘南亚高山草甸不同生境的18个植物样地的调查,研究了物种叶片N、P含量及其化学计量学特征,并结合分析土壤养分,探讨了它们与土壤N、P含量、有机质、水分及N∶P比值之间的关系.研究结果显示:甘南亚高山草甸植物叶片N含量在不同坡向之间的变化范围为4.46 ～ 26.59 mg· g-,平均为16.24 mg·g-1;P含量变化范围为0.71 ～ 1.98 mg·g-1,平均为1.37 mg·g-1;N∶P比值变化范围为6.43～ 17.75,平均为11.60.叶片N含量及N∶P在不同坡向梯度上没有显著差异(P＞0.05)；叶片P含量在不同生境下差异显著.物种之间叶片N、P含量及N∶P均有显著差异(P＜0.05),而物种与生境的交互作用对叶片N、P含量及N∶P之间差异不显著.根据限制性因子的N∶P阈值判断,该地区植物生长受N限制,这也体现了该地区植物对其生境的一种适应.
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