青海省高寒草地土壤水分变化特征  

Characteristics of Soil Moisture Change in High and Cold Grassland of Qinghai Province

作　　者：祁如英[1,2] 李应业 王启兰[3] 张成昭[3,4] 

机构地区：[1]中国气象局成都高原气象研究所开放实验室,四川成都610071 [2]青海气候中心,青海西宁810001 [3]中国科学院西北高原生物研究所,青海西宁810008 [4]青海省气象局监网处,青海西宁810008

出　　处：《水土保持通报》2009年第3期206-210,224,共6页Bulletin of Soil and Water Conservation

基　　金：中国气象局成都高原气象开放实验室基金(LPM2008008)

摘　　要：利用青海省天然草地的水分资料,初步统计得出天然草地土壤(0—50 cm)水分变化规律为:从西到东递增,从南到北两头略低,中略高。年内逐旬呈波动的"W"型,1989—2007年以0.8%/a的速率呈较明显下降趋势,其中0—20 cm土层以0.25%/a的速率呈显著下降,20—50 cm土层以0.04%/a的速率呈弱的下降。0—50 cm可分为活跃层(0—20 cm),次活跃层(20—40 cm),较稳定层(40—50 cm);草地年降水量≥520 mm以上的区域随深度而递减,在350 mm≤年降水量≤410 mm的区域土壤水分含量最多,并不一定在表层或深层,随深度而各异。从各区的变化趋势来看,兴海县不明显,曲麻莱县呈微弱下降,河南、甘德、海北县呈弱的下降,并且不同区域草地各层土壤的水分变化趋势及程度各异;气候变暖是土壤水分减少的直接原因,也是草地退化的主要直接原因之一。By using data from pasture observation on agro-meteorology by weather stations of Qinghai Province, the characteristics of soil moisture in native pasture are analyzed. Soil moisture increases from west to east, with slightly high values at the two boundaries from north to south. Soil moisture in the ten-day period of each year fluctuates in a ＂W＂ type. From 1989 to 2007, it declines obviously at the rate of 0.8%/a. In the 0-20 cm soil layer, the rate is 0.25%/a and in the 20-50 cm soil layer, 0.04%/a. The 0-50 cm soil profile may be divided into active layer （0-20 cm）, secondary active layer （20-40 cm）, and stable layer （40- 50 cm）. Soil water content decreases with soil depth under≥520 mm precipitation and differs in different depths when precipitation is between 350 and 410 ram. In terms of the change tendency, the change of soil moisture in Xinghai County is not obvious. It has a slightly weak drop in Ch＇u-ma-lai County and a weak drop in Henan, Gande, and Haibei Counties. The change tendency differs from its degree in different areas. Climate change is not only the direct cause of soil moisture reduction, but also the direct cause of pasture degradation. Soil moisture reduction is the main cause of pasture degradation.

关 键 词：天然草地 土壤水分 变化特征 

分 类 号：S152[农业科学—土壤学]