Greenhouse gas dynamics in tropical montane streams of Puerto Rico and the role of watershed lithology
Greenhouse gas dynamics in tropical montane streams of Puerto Rico and the role of watershed lithology
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DOI：
10.1007/s10533-022-00995-9
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发表时间：
2022-11
期刊：
影响因子：
4
通讯作者：
Allison M. Herreid;Carla López Lloreda;A. Wymore;J. Potter;W. McDowell
中科院分区：
文献类型：
--
作者：
Allison M. Herreid;Carla López Lloreda;A. Wymore;J. Potter;W. McDowell
溪流和河流中的主要温室气体二氧化碳(CO2)、甲烷(CH4)和一氧化二氮(N2O)可以对区域温室气体(GHG)收支做出重大贡献，而且每种气体似乎都对多个驱动因素做出了反应。最近的工作表明，热带水体可能是温室气体排放的热点，因为其流域的初级生产力很高，但热带溪流和河流在温室气体浓度和排放的研究中历来代表不足。我们使用波多黎各卢基洛山脉八个不同岩性和氧化还原条件的热带分水岭每周水化学和溶解气体数据的五年记录来检查对温室气体可变性的控制并估计气体通量。这三种气体中的溪流经常都是过饱和的，这表明这片热带地区的溪流是大气中温室气体的来源。CO2和N2O的浓度与来自周围景观的横向输入有关，而CH4的浓度与流中氧气的有效性和岩性有关。我们的结果强调了将热带地点纳入全球综合和预算的重要性，以及河流中生物和物理过程以及有助于向河流网络和大气输出气体的景观属性的作用。
The major greenhouse gases in streams and rivers, carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), can contribute significantly to regional greenhouse gas (GHG) budgets, and each appears to be responding to multiple drivers. Recent work suggests that tropical water bodies may be hot spots of GHG emissions due to high primary productivity in their watersheds, but tropical streams and rivers have historically been underrepresented in studies of GHG concentration and emissions. We use a five-year record of weekly water chemistry and dissolved gas data from eight tropical watersheds of varying lithology and redox conditions in the Luquillo Mountains of Puerto Rico to examine controls on GHG variability and estimate gas flux. Streams were frequently supersaturated in all three gases indicating that streams in this tropical landscape are sources of GHGs to the atmosphere. Concentrations of CO2and N2O were associated with lateral inputs from the surrounding landscape, whereas CH4concentrations correlated with in-stream oxygen availability and lithology. Our results underscore the importance of including tropical sites in global syntheses and budgets and the role of both in-stream biological and physical processes as well as landscape attributes that contribute to the export of gases to the fluvial network and atmosphere.