Passive regulation of soil biogeochemical cycling by root water transport
Passive regulation of soil biogeochemical cycling by root water transport
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根系水传输对土壤生物地球化学循环的被动调控
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
D. Drewry
中科院分区：
文献类型：
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作者：
J. Quijano;Praveen Kumar;D. Drewry
植被利用水力再分布（HR）吸收和再分布土壤水分的能力强烈影响着地表和次表层水分动态。这些动态反过来又通过控制分解和矿化速率以及离子迁移来影响土壤生物地球化学循环。本研究的目的是探讨这种耦合之间的HR和地球化学的数值模型。我们研究了有机质的分解和矿化，并分析了HR引起的分解速率差异是否会影响土壤中碳的长期储存以及根际硝酸盐（NO3 −）和铵（NH4+）的运动。这些动态研究的框架，包括多个植物物种之间的相互作用。HR对分解的净效应由所得水分和温度状态之间的权衡控制。这种权衡取决于地表附近细根的可用性，并影响土壤中碳的长期储存和垂直分布。HR还影响离子从土壤中的运输和吸收。它大大减少了硝酸盐的淋失，因此促进了植被根系对硝酸盐的吸收。此外，由HR诱导的反馈的幅度和模式也受到共存的不同植物物种的存在的影响。这些结果表明，植物通过相关过程（如HR）改变土壤水分可能对地下碳和氮的地球化学循环产生相当大的影响。
Surface and subsurface moisture dynamics are strongly influenced by the ability of vegetation to take up and redistribute soil moisture using hydraulic redistribution (HR). These dynamics in turn affect soil biogeochemical cycling through controls on decomposition and mineralization rates and ion transport. The goal of this study is to explore this coupling between HR and biogeochemistry using a numerical model. We examine decomposition and mineralization of organic matter and analyze whether differences in decomposition rates induced by HR influence the long‐term storage of carbon in the soil and the movement of nitrate ( NO 3− ) and ammonium ( NH 4+ ) in the rhizosphere. These dynamics are studied in a framework that incorporates the interaction between multiple plant species. The net effect of HR on decomposition is controlled by a trade‐off between the resultant moisture and temperature states. This trade‐off is conditioned by the availability of fine roots near the surface, and it impacts the long‐term storage and vertical distribution of carbon in the soil. HR also impacts the transport and uptake of ions from the soil. It reduces the leaching of nitrate considerably, and, therefore facilitates the uptake of nitrate by vegetation roots. Furthermore, the magnitude and patterns of the feedbacks induced by HR are also influenced by the presence of different plant species that coexist. These results suggest that the alteration of soil moisture by plants through associated processes such as HR can have considerable impact on the below‐ground biogeochemical cycling of carbon and nitrogen.