干旱区绿洲棉田土壤CO_2通量变化特征及温湿度影响分析  

Studies of Soil CO_2 Flux and Influencing Factors in Oasis Cotton Field of the Arid Area

作　　者：曹兴[1] 陈荣毅[2] 季枫 樊新燕 杨举芳 

机构地区：[1]新疆乌鲁木齐市气象局,乌鲁木齐830000 [2]中国气象局乌鲁木齐沙漠气象研究所,乌鲁木齐830002 [3]乌兰乌苏农业气象试验站,新疆石河子832100

出　　处：《中国农学通报》2012年第8期199-207,共9页Chinese Agricultural Science Bulletin

基　　金：国家自然科学基金项目"古尔班通古特沙漠生物结皮凝结水形成机理及其生态效应"(40801019);中央级公益性科研院所基本科研业务项目"北疆荒漠化土地开垦利用过程中土壤CO2通量的变化研究"(IDM200705);新疆气象局项目"干旱区棉田土壤CO2通量研究"(200825)

摘　　要：为了研究不同管理模式下干旱区绿洲棉田土壤CO2通量差异以及与土壤温湿度间的关系,可以为评价绿洲棉田生态系统对大气CO2的源/汇贡献提供参考依据。采用Li-8100土壤碳通量测量系统对天山北坡中段绿洲棉田土壤CO2通量进行动态测定,分析了土壤CO2通量的日、月变化特征及温湿度的影响。结果表明:在2009年5—10月土壤CO2通量日变化和月变化过程均为单峰型。滴灌地、漫灌地、弃耕地的土壤CO2通量(晴天)日均值分别为3.45、3.37、1.63μmol/(m2.s);峰值出现在15:00—20:00,谷值出现在4:00—6:00,6、7月土壤CO2通量高于其他月份;土壤CO2通量与温度呈不同程度的指数正相关性,气温、5cm地温较好地解释土壤CO2通量的变异量。土壤CO2通量与土壤湿度的相关性随着深度的变化表现不一;降水、灌溉等湿润事件对土壤CO2通量具有促进作用,多元回归分析模型可以解释67.4%的棉田、79.6%弃耕地土壤CO2通量受温度和湿度的共同控制。Study on soil CO 2 flux of oasis cropland in arid area under different management mode and relationship with soil temperature and humidity.This study provided reference for CO 2 contribution of oasis cropland ecosystem to atmospheric.Using LI-8100 Automated Soil CO 2 Flux System,we determined the rate of soil carbon dioxide emission in oasis cotton field in the north of Tianshan Mountain,we also evaluated the influence of temperature and soil moisture on soil CO 2 flux.The results indicated that：the diurnal fluctuation and monthly variation of soil CO 2 flux was characterized by single-peaked curve for the farmland.The average rate of soil CO 2 flux per month：drip irrigation field was 3.45 μmol/（m 2.s）,flooding field was 3.37 μmol/（m 2.s）,abandoned farmland was 1.63 μmol/（m 2.s）.In addition,the peak of rate of soil CO 2 flux appeared at about 15：00 to 20：00（Beijing time）,and the valley value occurred at about 4：00 to 6：00.And soil CO 2 flux was higher in June and July than other months.Correlation analysis showed that：exponential relationship between the rate of soil CO 2 flux and temperature in different field,5 cm ground temperature and air temperature showed positive correlation.But the soil CO 2 flux represents different correlation with soil moisture from 0 cm to 20 cm and the correlation with soil moisture weaken with soil depth at 10 cm,20 cm.Furthermore,the rate of soil CO 2 flux sites tended to increase rapidly after typical wetting events（rainfall and irrigation）.Soil temperature and moisture together controlled the soil CO 2 flux,and explained 67.4% of the variance in cotton field and 79.6% in abandoned farmland.

关 键 词：干旱区 绿洲棉田 土壤呼吸 特征 因子 

分 类 号：S153.4[农业科学—土壤学]