This study presents a novel concept for estimating net ecosystem production (NEP), the export of organic carbon (OC) from the productive surface layer to the deep‐water (hypolimnion) of 11 seasonally stratified lakes, varying in depth and trophic state. As oxygen remineralizes settling OC at a constant ratio, NEP is equivalent to the areal hypolimnetic mineralization rate (AHM) plus burial in the sediment. Two major interferences have to be considered, however. First, OC from terrestrial sources, not originating from primary production, consumes a fraction of oxidants. Second, sediment diagenetic processes of lakes in trophic transition (e.g., undergoing eutrophication or reoligotrophication) that are not in quasi‐steady‐state with actual fluxes of OC from the productive surface layer, bias the NEP estimation. In these cases, the flux of reduced substances diffusing from the sediment must be subtracted. This results in some overestimation for lakes with high allochthonous loads, and slight underestimation in lakes that are not in quasi‐steady‐state, because the actual sediment burial of autochthonous OC is small but not negligible. The presented approach requires data from routinely available monitoring and thus can be applied to historic data. The temporal integration over the productive season makes the estimation of NEP robust. Based on a historic 47 years long data record of Lake Geneva, NEP estimations (∼70 gC m⁻²) from AHM rates agree well with P and N export budgets from the productive surface zone, which help to verify and constrain the uncertainty of the estimates.

中文翻译：

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低聚有机碳汇估算的湖泊净生态系统产量

这项研究提出了一个新的概念，用于估算11个季节性分层湖泊的生态系统净产量（NEP），即从生产性表层向深水（hypolimnion）的有机碳（OC）出口，其深度和营养状态各不相同。由于氧气使矿物质以恒定的比例重新矿化OC，因此NEP等于区域低铁矿化速率（AHM）加上沉积物中的埋葬。但是，必须考虑两个主要干扰。首先，来自陆源的，不是源自初级生产的OC消耗了一小部分氧化剂。第二，在营养过渡期（例如，经历了富营养化或再富营养化）的湖泊沉积物成岩过程，它们与生产性表层的实际OC通量不处于准稳态，因而使NEP估计值产生偏差。在这些情况下，必须减去从沉积物中扩散出来的还原物质的通量。这导致了对高异源负荷湖泊的高估，而在非准稳态的湖泊中却被低估了，因为土生OC的实际埋藏量很小，但可以忽略不计。提出的方法需要来自常规可用监视的数据，因此可以应用于历史数据。在生产季节的时间积分使得对NEP的估计是鲁棒的。根据日内瓦湖已有47年历史的悠久数据记录，NEP估算值（约70 gC·m 因为土生OC的实际沉积物埋藏量很小，但可以忽略不计。提出的方法需要来自常规可用监视的数据，因此可以应用于历史数据。在生产季节的时间积分使得对NEP的估计是鲁棒的。根据日内瓦湖已有47年历史的悠久数据记录，NEP估算值（约70 gC·m 因为土生OC的实际沉积物埋藏量很小，但可以忽略不计。提出的方法需要来自常规可用监视的数据，因此可以应用于历史数据。在生产季节的时间积分使得对NEP的估计是鲁棒的。根据日内瓦湖已有47年历史的悠久数据记录，NEP估算值（约70 gC·mAHM汇率的⁻²）与生产性地表区域的P和N出口预算非常吻合，这有助于验证和约束估计的不确定性。