Air‐water gas exchange by waving vegetation stems
Air‐water gas exchange by waving vegetation stems
复制标题
通过挥动植物茎进行空气-水气体交换
DOI：
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复制
发表时间：
2016
期刊：
影响因子：
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通讯作者：
E. Variano
中科院分区：
文献类型：
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作者：
M. Foster‐Martinez;E. Variano
湿地地表水和大气之间的交换是由多种运动驱动的，从降雨影响到热对流和动物运动。在这里，我们研究了由风力驱动的植被移动的影响。风使新生植被的茎来回摆动，搅动水柱，促进气水交换。为了了解这种影响的大小，通过实验室实验测量了气体传递速度(K600值)。通过机械强迫模型树冠以与野外发现的频率和幅度相匹配的频率和幅度范围振荡，孤立地研究了植被波动。结果表明，植被波动引起的搅动产生的K600值在0.55~1.60 cm/h之间，K600与波动幅度和频率的依赖关系从实验室数据可以明显看出。这些结果表明，植被波动对气体传输具有不可忽视的影响，因此，它有助于从机制上理解支撑生物地球化学过程的通量。
Exchange between wetland surface water and the atmosphere is driven by a variety of motions, ranging from rainfall impact to thermal convection and animal locomotion. Here we examine the effect of wind‐driven vegetation movement. Wind causes the stems of emergent vegetation to wave back and forth, stirring the water column and facilitating air‐water exchange. To understand the magnitude of this effect, a gas transfer velocity (k600 value) was measured via laboratory experiments. Vegetation waving was studied in isolation by mechanically forcing a model canopy to oscillate at a range of frequencies and amplitudes matching those found in the field. The results show that stirring due to vegetation waving produces k600 values from 0.55 cm/h to 1.60 cm/h. The dependence of k600 on waving amplitude and frequency are evident from the laboratory data. These results indicate that vegetation waving has a nonnegligible effect on gas transport; thus, it can contribute to a mechanistic understanding of the fluxes underpinning biogeochemical processes.