Quantifying the effect of forest age in annual net forest carbon balance
Quantifying the effect of forest age in annual net forest carbon balance
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DOI：
10.1088/1748-9326/aaeaeb
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发表时间：
2018-12-01
影响因子：
6.7
通讯作者：
Reichstein, Markus
中科院分区：
文献类型：
--
作者：
Besnard, Simon;Carvalhais, Nuno;Reichstein, Markus
森林控制着陆地生物圈和陆地大气之间的碳(C)交换。从长期来看，森林与大气之间的净碳通量受到生态干扰和管理活动引起的森林覆盖面积和结构变化的显著影响。目前估算净生态系统生产力（NEP）的经验方法很少考虑林龄作为一个预测因子，它代表了生理过程的变化，可以对环境驱动因素做出不同的反应，以及干扰后的再生。本文对全球126个森林涡旋协方差通量点的气候、土壤性质、氮沉降、林龄和经营方式对森林NEP空间和年际变异的影响程度进行了观测综合。经验模型分别解释了62%和71%的年NEP时空变异和跨站点变异。模型结构研究表明，与养分有效性、土壤特征和气候等非生物因子相比，林龄是全球尺度NEP时空变异的主导因子。这些发现强调了林龄在利用经验方法量化新经济政策时空变化中的重要性。
Forests dominate carbon (C) exchanges between the terrestrial biosphere and the atmosphere on land. In the long term, the net carbon flux between forests and the atmosphere has been significantly impacted by changes in forest cover area and structure due to ecological disturbances and management activities. Current empirical approaches for estimating net ecosystem productivity (NEP) rarely consider forest age as a predictor, which represents variation in physiological processes that can respond differently to environmental drivers, and regrowth following disturbance. Here, we conduct an observational synthesis to empirically determine to what extent climate, soil properties, nitrogen deposition, forest age and management influence the spatial and interannual variability of forest NEP across 126 forest eddy-covariance flux sites worldwide. The empirical models explained up to 62% and 71% of spatio-temporal and across-site variability of annual NEP, respectively. An investigation of model structures revealed that forest age was adominant factor of NEP spatio-temporal variability in both space and time at the global scale as compared to abiotic factors, such as nutrient availability, soil characteristics and climate. These findings emphasize the importance of forest age in quantifying spatio-temporal variation in NEP using empirical approaches.