| 干旱区盐湖沿岸土壤呼吸特征及其影响因素 |
| |
| 引用本文： | 李典鹏,姚美思,孙涛,刘隋赟昊,贾宏涛.干旱区盐湖沿岸土壤呼吸特征及其影响因素[J].干旱区地理,2020,43(3):761-769. |
| |
| 作者姓名： | 李典鹏 姚美思 孙涛 刘隋赟昊 贾宏涛 |
| |
| 基金项目： | 国家自然科学基金项目(31560171);新疆农业大学研究生科研创新项目(XJAUGRI2018011);国家大学生创新训练计划项目(201510758004)资助 |
| |
| 摘 要： | 明确不同生态系统土壤碳排放规律及其影响因素对准确评估全球碳循环具有重要意义。为揭示干旱区典型盐湖沿岸土壤呼吸（Rs）、土壤呼吸温度敏感系数（Q10）变化特征及其影响因素，以新疆干旱区达坂城盐湖和巴里坤湖沿岸土壤为研究对象，在2015—2016年5~10月利用LI-8100土壤碳通量自动测量系统对盐湖沿岸土壤呼吸速率进行测定，分析了土壤呼吸季节性变化特征及其影响因子。结果表明，干旱区盐湖土壤呼吸变幅较大（0.07~11.59 μmol·m-2·s-1），平均值为2.45 μmol·m-2·s-1，7月土壤呼吸速率最高为4.69 μmol·m-2·s-1，10月最低（1.01 μmol·m-2·s-1）；土壤CO2累积排放量为9.30 g·m-2·d-1，7月累积排放量最大为17.82 g·m-2·d-1。Q10呈“降低—增加—降低”趋势，6月最低（2.25）9月最高（3.52），平均值为2.79。干旱区盐湖沿岸土壤呼吸受土壤有机碳（SOC）、5 cm土壤温度（ST5）、土壤含水量（SM）和土壤盐分（Salt）的共同影响，单因素模型模拟可解释土壤呼吸速率变化的41.7%~75.7%（R2=0.417~0.757，P＜0.05），多因子综合模型拟合结果最佳Rs=0.001×SOC+0.039×SM-0.534×Salt-0.116×ST5+5.06（R2=0.804，P=0.05），且均表明盐分是影响干旱区盐湖沿岸土壤呼吸速率的主要因子。因此，在考虑陆地生态系统碳收支和碳循环时不能忽略干旱区盐湖沿岸土壤碳过程，以及盐分对盐湖生态系统碳排放的影响。
|
| 关 键 词： | 碳排放 土壤盐分 达坂城盐湖 巴里坤湖 土壤温度敏感系数 |
| 收稿时间： | 2019-07-10 |
Characteristic of soil respiration and its influencing
factors on the coastal of saline lake in arid region |
| |
| LI Dian-peng,YAO Mei-si,SUN Tao,LIUSUI Yun-hao,JIA Hong-tao.Characteristic of soil respiration and its influencing
factors on the coastal of saline lake in arid region[J].Arid Land Geography,2020,43(3):761-769. |
| |
| Authors: | LI Dian-peng YAO Mei-si SUN Tao LIUSUI Yun-hao JIA Hong-tao |
| |
| Abstract: | Inland water ecosystems can act as greenhouse gas
sinks through the photosynthetic uptake of carbon dioxide (CO2) and
subsequent storage in long lived biomass or burial in soils.As
one of the most important carbon sinks,the carbon sedimentation rate of lakes
was related to the “source and sink” status of organic carbon content in coastal soils and their carbon
emission rates.We investigated the characteristics of soil respiration rate(Rs),the temperature
sensitivity of soil respiration (Q10)
variability,and its influencing factors in a typical arid saline lake coastal
area.In this study,we measured the soil respiration rate using a Li-8100
automated soil flux system (LI-COR,Lincoln,Nebraska,USA) from May to October
2015 and 2016 at Dabancheng and Barkol
saline lakes,Xinjiang,China.The dynamics of seasonal soil respiration rate and Q10 value,the correlation
between soil respiration and soil organic carbon (SOC),bulk density (BD),soil
temperature (ST),soil moisture (M),plant biomass (BIO),and salt and pH were also evaluated.The results showed as
follows:(1) the seasonal variation of soil respiration rate ranged from 0.07 to
11.59 μmol·m-2·s-1,and the monthly mean value was 2.45 μmol·m-2·s-1.The
soil respiration rate peaked once in July with a maximum value of 4.69 μmol·m-2·s-1,while the lowest respiration rate was in October (1.01 μmol·m-2·s-1).(2)
the monthly mean cumulative daily CO2 emission was
9.30 g·m-2·s-1,July
cumulative emission rate reach peak (17.82 g·m-2·s-1) .(3) the negative correlation between soil
respiration rate,soil temperature (5 cm ),and soil salt was significant (P < 0.05),and there was a positive
correlation between soil respiration rate,soil organic carbon,and soil
moisture.(4) the Q10 value
presented a single peak trend from July to October,and there was no significant
differences between the saline lakes,with minimum and maximum values of 2.25
and 3.52 in June and September,respectively.(5) the results of the linear model
showed the best fitting model for soil respiration rate and SOC,ST5,M,and soil salt content.The single factor model could explain 41.7%-75.7% of soil respiration
variability in the saline lakes coastal regions (P < 0.05),and
the multifactor synthesis model Rs=0.001×SOC+0.039×M - 0.534×Salt-0.116×ST5+5.06 (P=0.05) could
explain 80.4% of soil respiration variability.After eliminating SOC,ST5,SM,and Salt,the determinants of the three-factor regression equation (R2) were reduced to
0.024,0.027,0.104,and 0.269,respectively,indicating
that the contribution rate of salt was the largest among the factors affecting
the soil respiration rate.The results of single factor
and multifactor synthesis models showed that soil salt had the greatest
influence on soil respiration rate in the saline lakes coastal regions.Therefore,when
considering the carbon budget and cycle of terrestrial ecosystems,we cannot
ignore the soil carbon processes in saline lakes in arid regions and the
effects of soil salt on the carbon emissions from saline lake ecosystems in
arid regions. |
| |
| Keywords: | carbon emission soil salt Dabancheng Saline Lake Barkol Saline Lake temperature sensitive of soil respiration (Q10) |
|
| 点击此处可从《干旱区地理》浏览原始摘要信息 |
| 点击此处可从《干旱区地理》下载免费的PDF全文 |
|
