The Application Of Scaling Rules To Energy Flow In Stream Ecosystems

摘要 卡普兰0109122研究人员建议估计溶解有机物（DOM）在运输中对河流生态系统代谢的支持作用。本项目的具体目标是估算DOM的质量通量（例如，从水柱到河床的通量率），将其表示为几个不稳定性等级的通量之和，并表征每个不稳定性等级中DOM的各自浓度和吸收长度系数。吸收长度很容易转换为传质系数或周转率，通过涉及深度和水流速度的比例关系。量化河流中天然DOM的吸收类似于描述磷或铵的吸收（或螺旋），但由于天然DOM的多样性（即它由一系列不稳定性的化合物组成）以及同位素标记的天然DOM不可用的事实而变得复杂。该项目将使用在13 C大气中种植植物产生的13 C标记的DOM。13 C-DOm的纵向吸收将被分解为多个吸收长度（对应于多个不稳定性类别），估计为指数曲线之和。此外，在实验室生物反应器中的天然（12 C）DOM的吸收动力学将与标记的13 C-DOM的吸收动力学进行比较，并且该比较将用于缩放13 C-DOM注入的结果，以适当地描述流中天然DOM的吸收。

Abstract Kaplan 0109122 The investigators propose to estimate the contribution of dissolved organic matter (DOM) in transport to the support of stream ecosystem metabolism. The specific objective of this project is to estimate the mass flux of DOM (e.g., the rate of flux from the water column to the streambed), to represent this as the sum of fluxes from several lability classes, and to characterize the respective concentration and uptake length coefficient of DOM in each lability class. Uptake length converts easily to mass transfer coefficient or turnover rate through scaling relationships involving depth and water velocity. Quantifying the uptake of natural DOM in the stream is analogous to describing the uptake (or spiraling) of phosphorus or ammonium, but is complicated by the diversity of natural DOM (i.e. it consists of an array of compounds of varying lability), and the fact that isotopically-labeled natural DOM is not available. This project will use 13C-labeled DOM generated by growing plants in a 13C atmosphere. The longitudinal uptake of 13C -DOm will be resolved into multiple uptake lengths (corresponding to multiple lability classes), estimated as the sum of exponential-curves. In addition, the uptake kinetics of natural (12C) DOM in laboratory bioreactors will be compared to those of the labeled 13C-DOM, and this comparison will be used to scale the results of the 13C-DOM injection, to appropriately describe the uptake of natural DOM in the stream.