Large volcanic eruptions elucidate physiological controls of tree growth and photosynthesis
Large volcanic eruptions elucidate physiological controls of tree growth and photosynthesis
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DOI：
10.1111/ele.14149
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发表时间：
2022-12-01
期刊：
影响因子：
8.8
通讯作者：
Anderegg, William R. L.
中科院分区：
文献类型：
--
作者：
Cabon, Antoine;Anderegg, William R. L.
森林生产力预测仍然非常不确定，主要是因为基本的生理控制很难解开。大规模火山爆发对全球气候的短暂扰动提供了回顾性隔离潜在过程的独特机会。在这里，我们使用多代理数据集的树木年轮记录分布在北方半球的树木生长和光合作用的影响，并评估CMIP 6模型。树轮同位素记录表明，在喷发后的2-4年里，光合作用普遍增加，这可能是漫射光施肥的结果。我们发现的证据表明，增强光合作用瞬时驱动环宽度，但后者进一步表现出十年的异常，证明独立的增长和光合作用的反应。CMIP 6模拟再现了树木生长的总体下降，但没有捕捉到观察到的光合作用异常，其与树木生长或气候敏感性的脱钩过程，突出了关键的脱节，值得进一步关注，以改善气候变化下的森林生产力预测。
Forest productivity projections remain highly uncertain, notably because underpinning physiological controls are delicate to disentangle. Transient perturbation of global climate by large volcanic eruptions provides a unique opportunity to retrospectively isolate underlying processes. Here, we use a multi-proxy dataset of tree-ring records distributed over the Northern Hemisphere to investigate the effect of eruptions on tree growth and photosynthesis and evaluate CMIP6 models. Tree-ring isotope records denoted a widespread 2-4 years increase of photosynthesis following eruptions, likely as a result of diffuse light fertilization. We found evidence that enhanced photosynthesis transiently drove ring width, but the latter further exhibited a decadal anomaly that evidenced independent growth and photosynthesis responses. CMIP6 simulations reproduced overall tree growth decline but did not capture observed photosynthesis anomaly, its decoupling from tree growth or the climate sensitivities of either processes, highlighting key disconnects that deserve further attention to improve forest productivity projections under climate change.