Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plateau

Isotopic signature is a powerful tool to discriminate methane(CH_(4)) source types and constrain regional and global scale CH_(4) budgets.Peatlands on the Qinghai-Tibetan Plateau are poorly understood about the isotopic signature of CH_(4) due to the limited experimental conditions.In this study,three campaigns of diurnal air samples spacing 2-3 h were taken from an alpine peatland on the eastern Qinghai-Tibetan Plateau to investigate its source signal characteristics.Both CH_(4) concentration and its stable carbon isotope(δ^(13)C-CH_(4)) were measured to derive the carbon isotopic signature of the CH_(4) source using the Keeling plot technique.Diurnal variation patterns in CH_(4) concentration and δ^(13)C-CH_(4) were observed during summertime,with depleted δ^(13)C-CH_(4) signals and high CH_(4) concentration appearing at nighttime.The δ^(13)C-CH4 signature during summer was calculated to be-71 % ± 1.3%,which falls within the range of other wetland studies and close to high-latitude peatlands.The boundary layer dynamic and CH_(4) source were supposed to influence the measured CH_(4) concentration and δ^(13)C-CH_(4.)Further investigations of CH_(4) isotopic signals into the nongrowing season are still needed to constrain the δ^(13)C-CH_(4) signature and its environmental controls in this region.

Correction to:Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plateau

Correction to:Acta Geochim https://doi.org/10.1007/S11631-021-00477-Z The article“Variations of methane stable isotopic values from an Alpine peatland on the eastern Qinghai-Tibetan Plaleau"written by Qian Guo,Haijun Peng,Bing Hong,Hu Yao,Yongxuan Zhu,Hanwei Ding,Ning An,Yetang Hong was originally published electronically on the publisher's internet portal(currently SpringerLink)on 3 June 2021.There were some errors in the published article which should be corrected.The authors apologize for these errors and any confusion caused.

Biological effect of rare-earth elements on anti-oxidation enzymes in wheat under acid rain stress

Based on pot-culture experiments, the biological effect of rare-earth elements (REE) on antioxidation enzymes of wheat under acid rain stress was studied. The results show that both acid rain and REE can affect the activity of anti-oxidation enzymes of wheat to different extents. Under the acid rain stress, anti-oxidation enzymes (CAT, SOD) of wheat showed single peak curve with the decrease of pH values. After REE were applled, variation of activities of anti-oxidation enzymes was relatively stable and the peak value of variation curve would move in the direction of increased acidity. Under low acidity of acid rain, REE could reduce the sensitivity of anti-oxidation enzymes of wheat to acid rain stress significantly and promote the resistance of anti-oxidation enzymes of wheat to acid rain.

中国西北干旱区高寒湿地生态系统呼吸的季节和日变化及其环境控制

湿地储存了大量的碳,在全球碳循环和区域生态系统服务中发挥着重要作用。了解湿地碳交换动态对评估碳收支和预测其未来演变至关重要。虽然关于气候变化对生态系统碳循环的影响已经进行了大量的研究,但对中国西北干旱区高寒湿地碳排放的研究相对较少。本研究利用自动箱法(LI-8100A)对中国西北干旱区巴音布鲁克高寒湿地生态系统呼吸(ER)进行测量。结果显示,ER呈显著的“双峰”型日变化,峰值分别出现在北京时间的16:30和23:30。ER也呈明显的季节性变化规律,ER最大值(19.38μmolm^(-2)s^(-1))出现在8月,最小值(0.11μmolm^(-2)s^(-1))出现在12月。2018年生态系统的年排放量为678gCm^(-2),其中非生长季的排放量占全年总排放量的13%。非线性回归表明土壤5cm处温度和水分含量的变化是控制ER季节变化的主要因素。ER的日变化主要受空气温度和太阳辐射的共同影响。在较低的土壤温度和中等土壤水分含量(25%≤SWC≤40%)条件下,生态系统温度敏感性(Q_(10))较高。本研究加深了我们对高寒湿地生态系统CO_(2)排放的理解,并有助于评估干旱地区高寒湿地的碳收支。