Seasonal and diurnal variations in ecosystem respiration and environmental controls from an alpine wetland in arid northwest China
Seasonal and diurnal variations in ecosystem respiration and environmental controls from an alpine wetland in arid northwest China
复制标题
中国西北干旱高山湿地生态系统呼吸的季节和日变化及环境控制
DOI：
10.1093/jpe/rtac050
复制
发表时间：
2022-04
影响因子：
2.7
通讯作者：
Cheng Cai
中科院分区：
文献类型：
--
作者：
Hu Yao;Haijun Peng;Bing Hong;Hanwei Ding;Yetang Hong;Yongxuan Zhu;Jie Wang;Cheng Cai
抽象的。湿地储存了大量的碳储量，在全球碳循环和区域生态系统服务中至关重要。了解湿地碳交换的动态对于评估碳收支和预测其未来演变至关重要。尽管气候变化对生态系统碳循环的影响已有很多研究，但对中国西北干旱区高寒湿地碳排放的研究却很少。本研究采用LI-8100 A自动呼吸箱系统对巴音布鲁克高寒湿地生态系统呼吸进行了测定。ER日变化呈明显的双峰型，峰值出现在16：30和23：30（北京时间，UTC+8）。ER有明显的季节变化，最高值（19.38 μ molm-2s-1）出现在8月，最低值（0.11 μ molm-2s-1）出现在12月下旬。2018年全年呼吸速率为678 g C m-2，非生长季呼吸量占全年呼吸总量的13%。非线性回归分析表明，土壤温度和土壤含水量是影响ER季节变化的主要因素。ER的日变化主要受气温和太阳辐射的控制。在土壤温度较低、土壤含水量中等（25%≤SWC≤40%）的条件下，温度敏感性（Q10）较高。本研究加深了我们对高寒湿地生态系统CO2排放的理解，有助于评估干旱区高寒湿地的碳收支。
Abstract. Wetlands store large amounts of carbon stocks and are essential in both global carbon cycling and regional ecosystem services. Understanding the dynamics of wetland carbon exchange is crucial for assessing the carbon budgets and predicting their future evolution. Although many studies have been conducted on the effects of climate change on the ecosystem carbon cycle, little is known regarding carbon emissions from the alpine wetlands in arid northwest China. In this study, we used an automatic chamber system (LI-8100A) to measure ecosystem respiration in the Bayinbuluk alpine wetland in arid northwest China. The ER showed a significant bimodal diurnal variation, with peak values appearing at 16:30 and 23:30 (Beijing time, UTC+8). A clear seasonal pattern in ER was observed, with the highest value (19.38 μmol m -2 s -1) occurring in August and the lowest value (0.11 μmol m -2 s -1) occurring in late December. The annual ER in 2018 was 678g C m -2 and respiration during the non-growing season accounted for 13% of the annual sum. Nonlinear regression revealed that soil temperature at 5cm depth and soil water content were the main factors controlling the seasonal variations in ER. The diurnal variation in ER was mainly controlled by air temperature and solar radiation. Higher temperature sensitivity (Q10) occurred under conditions of lower soil temperatures and medium SWC (25%≤SWC≤40%). The present study deepens our understanding of CO2 emissions in alpine wetland ecosystems and help evaluate the carbon budget in alpine wetlands in arid regions.