Tracking the impacts of El Niño drought and fire in human-modified Amazonian forests.
Tracking the impacts of El Niño drought and fire in human-modified Amazonian forests.
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DOI：
10.1073/pnas.2019377118
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发表时间：
2021-07-27
影响因子：
11.1
通讯作者：
Barlow J
中科院分区：
文献类型：
--
作者：
Berenguer E;Lennox GD;Ferreira J;Malhi Y;Aragão LEOC;Barreto JR;Del Bon Espírito-Santo F;Figueiredo AES;França F;Gardner TA;Joly CA;Palmeira AF;Quesada CA;Rossi LC;de Seixas MMM;Smith CC;Withey K;Barlow J
亚马逊地区正在经历极端干旱和野火频率的增加。然而，它们对植物死亡率和碳储存的影响持续时间知之甚少，也不清楚在有人类干扰历史的森林中，影响是否会被放大。我们表明，植物死亡率保持在基线水平以上的3年，在受干旱影响的森林和2.5年，在受干旱和火灾影响的森林。人类干扰的历史导致更大的植物死亡率在森林中同时受到干旱和火灾的影响。我们对覆盖巴西亚马逊地区1.2%的区域进行的评估表明，区域干旱和火灾可能对世界碳平衡产生全球相关影响。随着人类面临前所未有的气候危机，热带森林的保护从未如此重要-其巨大的陆地碳储量可以通过气候和人为干扰转化为排放。然而，人们对这些影响的持续时间知之甚少，也不清楚在有人类干扰历史的森林中，影响是否会扩大。在这里，我们重点关注2015-16年厄尔尼诺现象的亚马逊震中，该地区占巴西亚马逊地区的1.2%。我们以高时间分辨率量化了极端厄尔尼诺（EN）干旱和大范围森林火灾对未受干扰和人为改造的森林中植物死亡率和碳损失的影响。死亡率仍然高于厄尔尼诺前的水平在EN干旱影响的森林为36个月，EN火灾影响的森林为30个月。在EN火灾影响的森林，人类干扰显着增加植物死亡率。我们对树木死亡率的生态和生理预测因子的调查表明，木材密度、树皮厚度和叶片氮含量较低的树木，以及经历过较大火灾强度的树木，更容易受到影响。在整个地区，2015-16年的厄尔尼诺现象导致估计25亿± 3亿棵树死亡，导致495 ± 94 Tg CO2的排放。厄尔尼诺发生三年后，植物的生长和补充只抵消了37%的排放量。我们的研究结果表明，限制森林干扰不仅有助于维持碳储量，而且还将在发生火灾时最大限度地提高亚马逊森林的抵抗力。
Amazonia is experiencing an increase in the frequency of extreme droughts and wildfires. However, the duration of their impacts on plant mortality and carbon stocks are poorly known, and it is unclear whether impacts are amplified in forests with a history of previous human disturbance. We show that plant mortality rates remain above baseline levels for over 3 y in forests affected by drought and 2.5 y in forests affected by both drought and fire. A history of human disturbance led to greater plant mortality in forests simultaneously affected by drought and fire. Our assessment of an area covering 1.2% of the Brazilian Amazon shows that regional drought and fires can have globally relevant impacts on the world’s carbon balance. With humanity facing an unprecedented climate crisis, the conservation of tropical forests has never been so important – their vast terrestrial carbon stocks can be turned into emissions by climatic and human disturbances. However, the duration of these effects is poorly understood, and it is unclear whether impacts are amplified in forests with a history of previous human disturbance. Here, we focus on the Amazonian epicenter of the 2015–16 El Niño, a region that encompasses 1.2% of the Brazilian Amazon. We quantify, at high temporal resolution, the impacts of an extreme El Niño (EN) drought and extensive forest fires on plant mortality and carbon loss in undisturbed and human-modified forests. Mortality remained higher than pre-El Niño levels for 36 mo in EN-drought–affected forests and for 30 mo in EN-fire–affected forests. In EN-fire–affected forests, human disturbance significantly increased plant mortality. Our investigation of the ecological and physiological predictors of tree mortality showed that trees with lower wood density, bark thickness and leaf nitrogen content, as well as those that experienced greater fire intensity, were more vulnerable. Across the region, the 2015–16 El Niño led to the death of an estimated 2.5 ± 0.3 billion stems, resulting in emissions of 495 ± 94 Tg CO2. Three years after the El Niño, plant growth and recruitment had offset only 37% of emissions. Our results show that limiting forest disturbance will not only help maintain carbon stocks, but will also maximize the resistance of Amazonian forests if fires do occur.*
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影响因子：
11.6
作者：
Brando, Paulo M.;Nepstad, Daniel C.;Putz, Francis E.
通讯作者：
Putz, Francis E.
影响因子：
9.8
作者：
Abatzoglou JT;Dobrowski SZ;Parks SA;Hegewisch KC
通讯作者：
Hegewisch KC
影响因子：
30.7
作者：
Ferreira, Joice;Lennox, Gareth D.;Barlow, Jos
通讯作者：
Barlow, Jos
影响因子：
16.6
作者：
Aragão LEOC;Anderson LO;Fonseca MG;Rosan TM;Vedovato LB;Wagner FH;Silva CVJ;Silva Junior CHL;Arai E;Aguiar AP;Barlow J;Berenguer E;Deeter MN;Domingues LG;Gatti L;Gloor M;Malhi Y;Marengo JA;Miller JB;Phillips OL;Saatchi S
通讯作者：
Saatchi S
影响因子：
9.8
作者：
de Azevedo, Tasso Rezende;Costa Junior, Ciniro;Kishinami, Roberto
通讯作者：
Kishinami, Roberto