地理学报

地理学报 ›› 2012, Vol. 67 ›› Issue (9): 1246-1254.doi: 10.11821/xb201209009

• 植物地理 • 上一篇    下一篇

念青唐古拉山北麓草甸海拔分布上限土壤温湿度的季节变化

俞洁辉1,2, 刘新圣1, 罗天祥1, 张林1   

  1. 1. 青藏高原环境变化与地表过程重点实验室中国科学院青藏高原研究所, 北京100085;
    2. 中国科学院研究生院, 北京100049
  • 收稿日期:2012-03-30 修回日期:2012-06-15 出版日期:2012-09-20 发布日期:2012-11-09
  • 通讯作者: 张林(1979-),男,云南人,副研究员,主要从事高山植物生态适应性研究.E-mail:zhanglin@itpcas.ac.cn E-mail:zhanglin@itpcas.ac.cn
  • 作者简介:俞洁辉(1989-),女,浙江人,硕士研究生,主要从事微气象和生态建模方面的研究.E-mail:yujh@itpcas.ac.cn
  • 基金资助:

    国家重点基础研究项目(2010CB951301); 国家自然科学基金项目(31170451)

Seasonal Variations of Soil Temperature and Moisture at the Upper Limit of Alpine Meadow in North-facing Slope of the Nianqingtanggula Mountains

YU Jiehui1,2, LIU Xinsheng1, LUO Tianxiang1, ZHANG Lin1   

  1. 1. Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100085, China;
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2012-03-30 Revised:2012-06-15 Online:2012-09-20 Published:2012-11-09
  • Supported by:

    The National Key Projects for Basic Research of China, No.2010CB951301; National Natural Science Foundation of China, No.31170451

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摘要： 本研究基于西藏念青唐古拉山北麓高山嵩草草甸海拔分布上限(5125 m) 地下10 cm和30 cm土壤温度和水分连续3 年(2008-2010 年) 的监测数据, 分析了草甸海拔分布上限土壤温度和未冻水含量的季节动态特征。结果表明:1) 土壤在4 月中下旬解冻, 10 月中下旬冻结;6-8月份土壤温度日振幅最大, 10 cm和30 cm分别为3.8℃和1.4℃;2) 土壤未冻水含量回升(下降) 在解冻(冻结) 开始后, 5-10 月份未冻水含量较高, 其中10 cm和30 cm 分别为2%~6%和15%~20%;3) 基于10 cm土壤温度推算的本地区高山嵩草草甸海拔分布上限的生长季在6 月初至8 月末或9 月初, 持续时间为80-87 天, 生长季平均土壤温度和含水量分别为6.78±0.73℃和4.14±0.91%, 生长季期间日最低温度集中在3~7℃之间(占90%以上天数);4) 与较低海拔处(4980 m) 相比, 高山嵩草草甸海拔分布上限处10 cm土壤温度和未冻水含量均明显偏低, 生长季8月份出现日最低温< 5℃的天数也明显增加。

关键词: 土壤温度, 土壤水分, 高山嵩草草甸海拔上限, 季节变化, 生长季长度, 念青唐古拉山

Abstract: Based on the three-year observations in a plot at the upper limit of the alpine Kobresia meadow (5125 m a.s.l.) on the Nianqingtanggula Mountains in the southern part of Namco Basin in Tibet, we analyzed the seasonal variations of soil temperature and moisture at soil depths of 10 and 30 cm. The results were obtained as follows. 1) The soil thawed in late April and froze in late October. The daily amplitude of soil temperature from June to August, which was 3.8℃ at 10 cm and 1.4℃ at 30 cm on average, reflected the highest values throughout the year. 2) The unfrozen soil water content increased (declined) when the soil began to thaw (freeze). And the soil moisture was relatively high from May to October, which was 2%-6% at 10 cm and 15%-20% at 30 cm. 3) Based on the soil temperature measurements at 10 cm depth, the growing season length for vegetation at the upper limit of the alpine Kobresia meadow was calculated to last 80-87 days, which began in early June and ended in late August or early September. And the average soil temperature and moisture were 6.78±0.73℃ and 4.14±0.91%, respectively. The lowest daily temperature during the growing season was mainly observed between 3℃ and 7℃. 4) Compared with the soil temperature and moisture at the lower altitude of 4980 m a.s.l., those at 5125 m were significantly lower. Also, the number of days of daily minimum temperature < 5℃ in August at the higher altitude was far more than that at the lower.

Key words: soil temperature, soil moisture, the upper limit of alpine Kobresia meadow, seasonal dynamics, growing season length, Nianqingtanggula Mountains