Met European Research Observatory, 82100 Benevento, Italy; Department of Science and Technology, University of Sannio, via Port'Arsa 11, 82100 Benevento, Italy.
IISD - Experimental Lakes Area Inc., 111 Lombard Ave., Winnipeg R3B 0T4, MB, Canada.
Sci Total Environ. 2016 Nov 15;571:50-8. doi: 10.1016/j.scitotenv.2016.07.112. Epub 2016 Jul 25.
The boreal forest of the northern hemisphere represents one of the world's largest ecozones and contains nearly one third of the world's intact forests and terrestrially stored carbon. Long-term variations in temperature and precipitation have been implied in altering carbon cycling in forest soils, including increased fluxes to receiving waters. In this study, we use a simple hydrologic model and a 40-year dataset (1971-2010) of dissolved organic carbon (DOC) from two pristine boreal lakes (ELA, Canada) to examine the interactions between precipitation and landscape-scale controls of DOC production and export from forest catchments to surface waters. Our results indicate that a simplified hydrologically-based conceptual model can enable the long-term temporal patterns of DOC fluxes to be captured within boreal landscapes. Reconstructed DOC exports from forested catchments in the period 1901-2012 follow largely a sinusoidal pattern, with a period of about 37years and are tightly linked to multi-decadal patterns of precipitation. By combining our model with long-term precipitation estimates, we found no evidence of increasing DOC transport or in-lake concentrations through the 20th century.
北半球的北方森林是世界上最大的生态区之一，拥有近三分之一的世界上完整的森林和陆地上储存的碳。温度和降水的长期变化被认为是改变森林土壤碳循环的因素之一，包括向受纳水体增加通量。在这项研究中，我们使用一个简单的水文模型和一个 40 年的数据集（1971-2010 年），从两个原始的北方湖泊（加拿大的 ELA）中的溶解有机碳（DOC），研究降水与景观尺度控制之间的相互作用，这些控制因素会影响森林流域中 DOC 的产生和输出到地表水中。我们的结果表明，一个简化的基于水文的概念模型可以使 DOC 通量的长期时间模式在北方景观中得到捕捉。在 1901-2012 年期间，从森林流域重建的 DOC 输出主要遵循正弦模式，周期约为 37 年，与降水的数十年模式紧密相关。通过将我们的模型与长期降水估计相结合，我们没有发现 20 世纪以来 DOC 运输或湖泊内浓度增加的证据。
