Woody debris is related to reach‐scale hotspots of lowland stream ecosystem respiration under baseflow conditions
Woody debris is related to reach‐scale hotspots of lowland stream ecosystem respiration under baseflow conditions
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DOI：
10.1002/eco.1952
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发表时间：
2018-07
期刊：
影响因子：
2.6
通讯作者：
P. Blaen;M. Kurz;J. Drummond;J. Knapp;C. Mendoza‐Lera;N. Schmadel;M. Klaar;A. Jäger;S. Folegot;J. Lee-Cullin;A. Ward;J. Zarnetske;T. Datry;A. Milner;J. Lewandowski;D. Hannah;S. Krause
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文献类型：
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作者：
P. Blaen;M. Kurz;J. Drummond;J. Knapp;C. Mendoza‐Lera;N. Schmadel;M. Klaar;A. Jäger;S. Folegot;J. Lee-Cullin;A. Ward;J. Zarnetske;T. Datry;A. Milner;J. Lewandowski;D. Hannah;S. Krause
河流代谢是水生生态系统功能的基本综合指标。然而，人们尚不清楚物理河道形式的异质性，特别是与河道内木质残骸有关并由其引起的异质性，如何调节低地溪流的新陈代谢。我们结合保守型和反应型河流示踪剂来研究河道形态模式与水文输送（形式）和代谢过程之间的关系，以森林低地河流基流的生态系统呼吸（功能）为特征。河流范围的生态系统呼吸与具有大量木质碎片的位置（“热点”）有关。相比之下，之前记录或假设影响河流代谢的几乎所有其他测量的水文和地貌变量并不能显着解释生态系统呼吸。我们的结果表明，在基流条件下，低地河流系统（本研究）和较小的高地河流（大多数先前的研究）之间对生态系统呼吸的物理控制存在关键差异。因此，这些发现对于根据水力输送参数预测生物地球化学转化率的反应性输送模型、代表更大网络规模的生物流过程的升级框架以及水生生态系统的有效管理和恢复具有重要意义。
Stream metabolism is a fundamental, integrative indicator of aquatic ecosystem functioning. However, it is not well understood how heterogeneity in physical channel form, particularly in relation to and caused by in‐stream woody debris, regulates stream metabolism in lowland streams. We combined conservative and reactive stream tracers to investigate relationships between patterns in stream channel morphology and hydrological transport (form) and metabolic processes as characterized by ecosystem respiration (function) in a forested lowland stream at baseflow. Stream reach‐scale ecosystem respiration was related to locations (“hotspots”) with a high abundance of woody debris. In contrast, nearly all other measured hydrological and geomorphic variables previously documented or hypothesized to influence stream metabolism did not significantly explain ecosystem respiration. Our results suggest the existence of key differences in physical controls on ecosystem respiration between lowland stream systems (this study) and smaller upland streams (most previous studies) under baseflow conditions. As such, these findings have implications for reactive transport models that predict biogeochemical transformation rates from hydraulic transport parameters, for upscaling frameworks that represent biological stream processes at larger network scales, and for the effective management and restoration of aquatic ecosystems.