在气候变暖的情况下,从高海拔河流中增加碳出口
Sen Xu1, Si-Liang Li1, Aaron Bufe2
1Institute of Surface-Earth System Sciences, School of Earth System Science, Tianjin University, Tianjin 300072, China.
Environmental science & technology
|April 11, 2024
概括
山地生态系统的变暖显著增加了河流的溶解无机碳 (DIC) 出口,特别是在永久土地区. 永久土的融化增加了碳的释放,改变了河流碳动态.
科学领域:
- 环境科学 环境科学
- 地质化学 地质化学
- 气候科学 气候科学
背景情况:
- 高海拔的山脉面临着快速变暖,影响陆地碳出口.
- 这些敏感地区气候变暖对河流碳出口的影响尚不清楚.
- 永久土融是高山环境中的一个关键过程.
研究的目的:
- 调查全球变暖对清海-西藏高原河流中溶解无机碳 (DIC) 和有机碳出口的影响.
- 为了区分变暖和永久土融化对河流碳动态的影响.
- 分析碳同位素和度的长期和短期数据集.
主要方法:
- 收集了关于溶解无机碳 (DIC) 的长期数据.
- 从金沙河 (JSR) 和雅龙河 (YLR) 获取的DIC, δ13C-DIC和有机碳的短期数据.
- 分析了与温度,降水和排放有关的碳度和流量.
主要成果:
- 高海拔JSR (51%的永久土) 的变暖 (>3°C) 和降水增加导致DIC度增加35%,DIC流量增加110%.
- 在较低海拔的YLR (14%的永久土) 中相似的变暖并没有导致DIC的类似增加.
- 在JSR中的DIC度随着变暖而从稀释转变为化学静止,在高排放下较轻的δ13C-DIC表明永久土融化的贡献.
结论:
- 变暖是改变高海拔河流系统侧向碳出口的主要驱动因素.
- 永久土融化通过增强土壤呼吸和气候变化,显著提高DIC生产和出口.
- 河流碳出口模式因变暖而改变,永久土地区显示出放大反应.
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