Abstract: Altitude affects the vertical distribution of plant and plant has close relationship with the habitat soil.In order to explore the relationship of altitude with the characteristics of the soil and illustrate the it’s influencing process on the ecological structure and function,the soil nutrient contents such as pH,available N,available P,organic matter,total S,available Ca,Mg,K,and Na were studied from various altitudes from 2800 to 4100 m of alpine rangeland on the eastern Qinghai-Tibetan Plateau.The results indicate that the contents of soil organic matter,total S,available N,P,Ca,and Mg,and soil pH were significantly correlated to altitude.The contents of soil organic matter,total S,available N,P,and Mg firstly reduced to the lowest values at altitude from 3200 to 3400 m,and then gradually increased along with increased sampling altitude.But the soil available Ca content and pH decreased gradually along with altitude increasing.Available K and Na showed no obvious tendency along with altitude.In general,the nutrients in organic or other stable forms in soil showed notable relationship with the altitude but not between the soluble or erosive matters and altitude.Except for the easily erosive matter,many nutrients did not lack in the soil of Qinghai-Tibetan Plateau,which suggest the climate could be the most important restrictive factor to the productivity of alpine rangeland.

Key words: Altitude, Soil characteristics, Qinghai-Tibetan Plateau, Physicochemical index

摘要： 海拔对植物的影响呈现垂直地带性,植物与土壤之间有着密切的关系,为了探明土壤特征与海拔之间的是否存在明显的规律性,探究海拔高度与土壤性质之间的相关关系,进而解释海拔高度影响生态结构和功能的过程。对青藏高原高寒草地不同海拔高度(2800~4100 m)的土壤进行取样,分别采用电位测定法、重铬酸钾容量法-外加热法、扩散吸收法、碳酸氢钠浸提-钼锑抗比色法、Mg(NO₃)₂氧化-BaSO₄比浊法、EDTA容量法、乙酸铵浸提-火焰光度法对pH值、有机质、有效氮、有效磷、全硫、有效钙和镁、有效钾、钠进行测定。结果表明:土壤pH值、有机质、有效氮、有效磷、有效钙和镁、全硫含量与海拔之间具有显著的相关关系,土壤有机质、全硫、有效氮、有效磷和有效镁的含量呈现随着海拔高度的升高先是逐渐降低,含量最低点出现在海拔3200~3400 m,后随着海拔的升高逐渐增加,有效钙含量及pH值随着海拔高度的增加而递减的趋势。然而,有效钾、钠的含量与海拔之间不存在明显的相关关系。总的来说,多种能够以有机形式或其他稳定形式存在的营养元素含量在不同海拔高度呈现一定的规律性变化,而易淋溶的营养元素的含量由于缺乏稳定形式导致不同海拔之间没有明显的规律性。

关键词: 海拔高度, 土壤特性, 青藏高原, 理化指标