Forest Ecology and Restoration Group, Department of Life Sciences, Universidad de Alcalá, 28805, Alcalá de Henares, Madrid, Spain.
Climate Change Impacts and Risks in the Anthropocene (C-CIA), Institute for Environmental Sciences, University of Geneva, Boulevard Carl-Vogt 66, 1205, Geneva, Switzerland.
Nat Commun. 2017 Dec 20;8(1):2222. doi: 10.1038/s41467-017-02319-0.
The North Atlantic Oscillation (NAO) depicts annual and decadal oscillatory modes of variability responsible for dry spells over the European continent. The NAO therefore holds a great potential to evaluate the role, as carbon sinks, of water-limited forests under climate change. However, uncertainties related to inconsistent responses of long-term forest productivity to NAO have so far hampered firm conclusions on its impacts. We hypothesize that, in part, such inconsistencies might have their origin in periodical sea surface temperature anomalies in the Atlantic Ocean (i.e., Atlantic Multidecadal Oscillation, AMO). Here we show strong empirical evidence in support of this hypothesis using 120 years of periodical inventory data from Iberian pine forests. Our results point to AMO NAO and AMONAO phases as being critical for forest productivity, likely due to decreased winter water balance and abnormally low winter temperatures, respectively. Our findings could be essential for the evaluation of ecosystem functioning vulnerabilities associated with increased climatic anomalies under unprecedented warming conditions in the Mediterranean.
北大西洋涛动（NAO）描述了年度和十年振荡模式的可变性，这些可变性导致了欧洲大陆的干旱期。因此，北大西洋涛动在评估水限制森林在气候变化下作为碳汇的作用方面具有很大的潜力。然而，与长期森林生产力对北大西洋涛动的不一致反应相关的不确定性，迄今为止一直阻碍了对其影响的明确结论。我们假设，部分原因可能在于大西洋的海面温度异常（即大西洋多年代际振荡，AMO）。在这里，我们使用伊比利亚松林 120 年的定期清查数据提供了有力的实证证据支持这一假设。我们的结果表明，AMO-NAO 和 AMONAO 阶段对森林生产力至关重要，这可能分别是由于冬季水分平衡减少和异常低的冬季温度造成的。我们的发现对于评估与地中海前所未有的变暖条件下增加的气候异常相关的生态系统功能脆弱性可能至关重要。
