Tree growth and stem carbon accumulation in human-modified Amazonian forests following drought and fire
Tree growth and stem carbon accumulation in human-modified Amazonian forests following drought and fire
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DOI：
10.1098/rstb.2017.0308
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发表时间：
2018-11-19
影响因子：
6.3
通讯作者：
Barlow, Jos
中科院分区：
文献类型：
--
作者：
Berenguer, Erika;Malhi, Yadvinder;Barlow, Jos
人类改造的森林在亚马逊盆地越来越多，但人们对极端气候事件和由此产生的野火如何影响树干生长知之甚少。在这里，我们首次评估了人为干扰与厄尔尼诺介导的干旱和火灾对树木生长和碳积累的影响。我们发现，经过2.5年的连续测量，未受干扰和人为改造的森林之间的树干碳积累没有差异。此外，厄尔尼诺造成的极端干旱并没有影响幸存树木的碳积累率。在最近被烧毁的森林中，树木的生长速度明显高于未被烧毁的森林，而不管它们以前是否受到人类的干扰。木材密度是唯一的重要因素，有助于解释在燃烧和未燃烧的森林树木之间的增长差异，与低木材密度的树木生长显着更多的燃烧现场。我们的研究结果表明，茎碳积累是抵抗人类干扰和一次性的极端干旱事件，它是刺激野火后立即。然而，这些结果应该被谨慎地看待--如果不考虑碳损失、补充和物种组成的长期变化，我们就无法完全理解干旱和火灾对人类改造森林碳平衡的影响。本文是讨论会议议题“2015/2016厄尔尼诺对陆地热带碳循环的影响：模式、机制和含义”的一部分。
Human-modified forests are an ever-increasing feature across the Amazon Basin, but little is known about how stem growth is influenced by extreme climatic events and the resulting wildfires. Here we assess for the first time the impacts of human-driven disturbance in combination with El Nino-mediated droughts and fires on tree growth and carbon accumulation. We found that after 2.5 years of continuous measurements, there was no difference in stem carbon accumulation between undisturbed and human-modified forests. Furthermore, the extreme drought caused by the El Nino did not affect carbon accumulation rates in surviving trees. In recently burned forests, trees grew significantly more than in unburned ones, regardless of their history of previous human disturbance. Wood density was the only significant factor that helped explain the difference in growth between trees in burned and unburned forests, with low wood-density trees growing significantly more in burned sites. Our results suggest stem carbon accumulation is resistant to human disturbance and one-off extreme drought events, and it is stimulated immediately after wildfires. However, these results should be seen with caution-without accounting for carbon losses, recruitment and longer-term changes in species composition, we cannot fully understand the impacts of drought and fire in the carbon balance of human-modified forests.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Nino on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.