摘要
以干旱区高寒湿地草甸土和绿洲农田灰漠土为研究对象,采用原状土柱研究了不同初始水分条件下冻融作用对两种类型土壤CO_2短期排放的影响。结果表明,在30%～50%和15%～20%水分处理下,草甸土和灰漠土在冻结过程的1h内CO_2排放速率迅速降低,在融化过程的5h内CO_2排放速率迅速增加,其中15%～20%水分处理组CO_2排放速率受抑制和激发影响显著(P <0.05)。在100%水分处理下,草甸土和灰漠土CO_2排放在冻结和融化作用初期12h内均未出现显著抑制和激发现象(P>0.05);由冻融短期试验得出,冻结作用显著抑制了土壤CO_2排放速率,而融化作用促进了CO_2排放速率。冻融作用对草甸土壤CO_2排放的影响高于农田灰漠土。不同土壤类型冻融作用下土壤CO_2排放与温度相关性存在差异,草甸土壤CO_2排放速率与土壤温度间有极显著的正相关关系(P <0.01),而灰漠土土壤CO_2排放速率仅在水分为饱和含水量的30%～50%处理下与土壤温度呈显著正相关关系(P <0.05)。
Freezing and thawing have an important effect on soil CO2emissions in regions at mid-high latitude.The effects of water content on the short-term CO2fluxes during freeze-thaw cycles were evaluated using the undisturbed soil columns of Typical Alpine Wetland and farmland grey desert soil in winter.Results showed that the emission rate of CO2decreased rapidly in the meadow soil and gray desert soil in the first hour of freezing period under the water content treatments of30%-50%and15%-20%,and the emission rate of CO2increased rapidly within5hours at the stage of melting.The inhibition and excitation effects of freezing-thawing cycle on soil CO2emissions were significant under the15%-20%water content treatment(P<0.05).During the first12hours of freezing and thawing,no significant inhibition and excitation effects of CO2emission under100%water treatment were found for meadow soil and grey desert soil(P>0.05).Results of10-day freeze-thaw test indicated that freezing significantly inhibited the emission rate of soil CO2,while thawing promoted the emission rate of CO2.The effect of freezing and thawing on CO2emission in meadow soil was higher than that in farmland grey desert soil.The correlation between CO2emission and soil temperature was different in different soil types under freeze-thaw action.There was a significant positive(P<0.01)correlation between soil CO2emission rate and soil temperature under the meadow soil with high organic carbon content.However,the relationships between the soil CO2emission rate and the soil temperature was only positively correlated(P<0.05)under the30%-50%water content treatment for the gray desert soil with low organic carbon.
作者
朱新萍
胡保安
张雨佳
杨磊
ZHU Xin-ping;HU Bao-an;ZHANG Yu-jia;YANG Lei(College of Pratacultural and Environmental Sciences,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Communications Construction Administrative Bureau,Urumqi 830049,China;Supervision Team of Qinling Ecological Environment Protection in Baqiao District of Xi’an City, Xi’an 710025,China)
出处
《新疆农业大学学报》
CAS
2018年第1期61-66,共6页
Journal of Xinjiang Agricultural University
基金
国家自然科学基金项目(41305136)
关键词
冻融作用
草甸土
灰漠土
CO2排放
freeze-thaw action
meadow soil
grey desert soil
CO 2 emissions
