Multidecadal Trends in Organic Carbon Flux Through a Grassland River Network Shaped by Human Controls and Climatic Cycles
Multidecadal Trends in Organic Carbon Flux Through a Grassland River Network Shaped by Human Controls and Climatic Cycles
复制标题
DOI：
10.1029/2021gl096885
复制
发表时间：
2022-02
影响因子：
5.2
通讯作者：
S. Johnston;Panditha V.S.L. Gunawardana;S. Rood;M. Bogard
中科院分区：
文献类型：
--
作者：
S. Johnston;Panditha V.S.L. Gunawardana;S. Rood;M. Bogard
由于广泛的农业发展和河流治理，草原是地球上受干扰最严重的系统之一。为了确定这些因素如何影响碳(C)在河流网络中的运动，我们量化了草地河流网络中溶解有机C （DOC）通量的多年代际、季节模式。尽管有近几十年的城市化和污水排放，但我们没有观察到20至40年月度样本记录中DOC通量的趋势。DOC通量的高年际变率与气候遥相关，最强烈的是太平洋年代际振荡。人类活动对通量的季节性影响更为明显，大部分小流域的DOC通量以春季出口为主，而河口受下游流量控制，季节性变化不明显。在草原地区，人类对DOC通量的影响是复杂的，由于水文气候变率的增加，在当代监测记录中可能难以识别细微的长期变化。
Grasslands are among the most disturbed systems on Earth due to extensive agricultural development and river regulation. To define how these factors impact the movement of carbon (C) through river networks, we quantified multi‐decadal, seasonal patterns of dissolved organic C (DOC) fluxes through a grassland river network. Despite urbanization and effluent release in recent decades, we did not observe trends in DOC fluxes over 20 to 40 year monthly sample records. High interannual variability in DOC flux was linked to climate teleconnections, most strongly the Pacific Decadal Oscillation. Human impacts were more apparent on the seasonality of flux, since spring export dominated DOC flux in most sub‐watersheds, but seasonal changes were absent at the river mouth due to downstream flow control. In grassland regions, human impacts on DOC flux are complex, and subtle long‐term changes may be difficult to identify in contemporary monitoring records due to increasing hydro‐climatic variability.