【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雅北麓湖盆区,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0~20 cm土壤容重、20~30 cm土壤含水量、速效钾、全氮含量显著正相关,与20~30 cm土壤容重、土壤速效磷和全磷含量显著负相关.更多还原

【Abstract】 The distribution characteristics of soil N/P ratio in alpine grassland ecosystem of Qinghai-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 into 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,respectively.However,it showed significant negative correlation with soil bulk density at 20-30 cm depth,contents of soil available P and total P,respectively.更多还原