Short-term effects of drought on tropical forest do not fully predict impacts of repeated or long-term drought: gas exchange versus growth.
Short-term effects of drought on tropical forest do not fully predict impacts of repeated or long-term drought: gas exchange versus growth.
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DOI：
10.1098/rstb.2017.0311
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发表时间：
2018-10-08
期刊：
影响因子：
--
通讯作者：
Rowland L
中科院分区：
文献类型：
--
作者：
Meir P;Mencuccini M;Binks O;da Costa AL;Ferreira L;Rowland L
热带雨林对干旱（例如厄尔尼诺现象期间）的短期反应是否足以预测长期变化或反复干旱的变化？我们利用世界上唯一的热带森林长期（16 年）干旱实验来检验短期测量（1-2 年）的可预测性。干旱森林的蒸腾作用达到最大：在 16 年的研究中，它消耗了所有可用的径流。叶子的光合作用能力得以维持，但只有在树大小组的平均值时才得以维持。干旱森林的年蒸腾量低于对照，最初是由于叶面气孔控制而减少（在高生物量时）。第三年后树木死亡率增加，导致总体生物量损失 40%；从长远来看，蒸腾作用的主要限制是边材面积的相应减少。改变的树木死亡风险可能可以通过土壤和植物水力学来预测，但需要额外的监测来测试未来的生物量是否会稳定或崩溃。同化物的分配随着时间的推移而变化：茎生长和繁殖产量在短期内下降，但在资源可用性发生与死亡率相关的变化后，两者都表现出长期的恢复能力，部分或完全恢复。通过更多地使用优化和概率建模方法，将更有效地理解和模拟这些现象以及分配中的相关权衡。本文是讨论会议问题“2015/2016 厄尔尼诺现象对陆地热带碳循环的影响：模式、机制和影响”的一部分。
Are short-term responses by tropical rainforest to drought (e.g. during El Niño) sufficient to predict changes over the long-term, or from repeated drought? Using the world's only long-term (16-year) drought experiment in tropical forest we examine predictability from short-term measurements (1–2 years). Transpiration was maximized in droughted forest: it consumed all available throughfall throughout the 16 years of study. Leaf photosynthetic capacity was maintained, but only when averaged across tree size groups. Annual transpiration in droughted forest was less than in control, with initial reductions (at high biomass) imposed by foliar stomatal control. Tree mortality increased after year three, leading to an overall biomass loss of 40%; over the long-term, the main constraint on transpiration was thus imposed by the associated reduction in sapwood area. Altered tree mortality risk may prove predictable from soil and plant hydraulics, but additional monitoring is needed to test whether future biomass will stabilize or collapse. Allocation of assimilate differed over time: stem growth and reproductive output declined in the short-term, but following mortality-related changes in resource availability, both showed long-term resilience, with partial or full recovery. Understanding and simulation of these phenomena and related trade-offs in allocation will advance more effectively through greater use of optimization and probabilistic modelling approaches. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.
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影响因子：
1.5
作者：
CERMAK, J;DEML, M;PENKA, M
通讯作者：
PENKA, M
DOI：
10.1098/rstb.2017.0315
发表时间：
2018-10-08
期刊：
Philosophical transactions of the Royal Society of London. Series B, Biological sciences
影响因子：
--
作者：
Eller CB;Rowland L;Oliveira RS;Bittencourt PRL;Barros FV;da Costa ACL;Meir P;Friend AD;Mencuccini M;Sitch S;Cox P
通讯作者：
Cox P
DOI：
10.1111/nph.13927
发表时间：
2016-07
期刊：
The New phytologist
影响因子：
--
作者：
Binks O;Meir P;Rowland L;da Costa AC;Vasconcelos SS;de Oliveira AA;Ferreira L;Christoffersen B;Nardini A;Mencuccini M
通讯作者：
Mencuccini M
影响因子：
30.7
作者：
Boisier, Juan P.;Ciais, Philippe;Guimberteau, Matthieu
通讯作者：
Guimberteau, Matthieu
影响因子：
56.9
作者：
Bousquet, P;Peylin, P;Tans, PP
通讯作者：
Tans, PP