中文摘要：

采用野外调查和室内分析相结合的方法，研究了青藏高原高寒草原生态系统土壤N／P的分布特征．结果表明：青藏高原高寒草原生态系统土壤N／P总体上呈现出西高东低、斑块状交错分布的格局，N／P的高值区主要集中在藏北高原腹地和喜马拉稚北麓湖盆区，不同草地类型和不同自然地带土壤N／P差异显著．不同草地类型土壤N／P自上而下可分为低．高．低．高型、低．高．低型、低．高型、高-低-高-低型和高-低-高型等5个类型，表土层与底土层N／P差异显著．土壤N／P与0～20cm土壤容重、20～30cm土壤含水量、速效钾、全氮含量显著正相关，与20～30cm土壤容重、土壤速效磷和全磷含量显著负相关．

英文摘要：

The distribution characteristics of soil N/P ratio in alpine grassland ecosystem of Qing- hai-Tibet Plateau were surveyed by field investigation and laboratory analysis. Horizontally, soil N/ P ratio was generally higher in west and lower in east in a manner of staggered patch distribution, with higher N/P ratios mainly centralized in the hinterland of northern part of Tibet Plateau and in the lake basin area of the northern foot of Himalayas. Significant differences in soil N/P ratio were observed among grassland types and natural transects. Vertically, the distribution of N/P ratio along the soil profile from aboveground to underground among different grass types could be categorized in- to five patterns, including low-high-low-high, low-high-low, low-high, high-low-high-low, and high-low-high. The N/P ratio showed a significant positive correlation with soil bulk density at 0-20 cm depth, soil water content at 20-30 cm depth, contents of soil available K and total nitrogen, re- spectively. However, it showed significant negative correlation with soil bulk density at 20-30 cm depth, contents of soil available P and total P, respectively.