Assessing the impacts of the 2010 drought on Amazon zone of transition

评估 2010 年干旱对亚马逊过渡区的影响

• 批准号: NE/I02982X/1
• 负责人: Oliver Phillips
• 金额: $ 6.72万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI02982X%2F1
• 关键词: Assessing; impacts; 2010; drought; Amazon

In 2010 the Amazon Basin experienced unusually dry conditions, a second major drought in 5 years, a pattern which is remarkably similar to some predictions of the future climate of the region. This is because most climate models predict an increase in dry season intensity, and all an increase in temperature in the coming century as a consequence of global climate change. Whether or not long-term climate change is already involved the current event can help us evaluate how humid forest, deciduous forests and savanna ecosystems and species respond to drying, so helping assess the potential scale of impacts as the Amazon climate dries. Our team has a large network of on-the-ground sample plots in the region, and because these are standardised they represent an excellent opportunity to measure the actual impacts of drought. We already did this with the severe 2005 drought (described then as 'the drought of the century' but surpassed in extent this year). In this proposal we focus on our sites at the southern fringes of Amazonia, an area very strongly affected by the 2010 drought.This large area is a 'zone of tension' between Amazon moist forest species, deciduous species, and savanna, with the various vegetation types sometimes adjacent in the same sites. Here we have 30 permanent plots available so we are able for the first time to measure the on-the-ground impacts on different species and vegetation formations at this forest/savanna mixing zone. This is important because it is expected that within these zones of ecological tension that long-term vegetation changes will first be observed, and these areas of high diversity and high carbon storage could significantly affect regional carbon emissions.We plan to do the following:1) Recensus 30 southern Amazon plots to record tree growth and vegetation productivity.2) Remeasure nearly 500 trees where we have pre-drought measures of details of their structure, to assess if drought has changed them.3) Install high-precision measurement tools ("dendrometers") on trees of key species, to enable better monitoring of future droughts4) Analyse data collected from (1) & (2) to test our hypotheses:1. The 2010 drought caused biomass carbon loss from forest but not savanna. We expect savanna to prove more resilient than forest, and for forest responses to mirror those of 2005.2. The 2010 drought accelerated tree death and reduced growth in the forest but not the savanna. We expect forest species to be more sensitive than savanna species when faced with the same degree of drying.3. Forest & savanna plots that had the greatest biomass loss and/or mortality are those with shallowest soils. We expect soil depth to affect the drought response, with shallower soils having fewer moisture reserves.4. Within each stand, species which also occur in drier areas were more drought-resistant than those already at the dry end of their range. We expect that the risk a tree faces from drought is related to its geographic distribution, so that species that are typically found in moister climates will be more drought-sensitive than their neighbours.5. Species differences in drought sensitivity are related to variation in structural traits. We expect the more drought-resistant evergreen trees will have a more conservative hydraulic structure, such as denser wood.The expected outcomes of this research are:1) Improved quantification of the sensitivity of transitional Amazon forest to drought.2) A first assessment of the differential sensitivity of forest and savanna trees to drought conditions.3) By integrating (1) & (2), understand better the chances of savanna replacing forest in the "zone of tension", and even into core Amazon forests, as the climate dries.4) Improved understanding of the physiological basis of drought-resistance and the importance of soil conditions.5) The infrastructure installed to allow local collaborators to evaluate effects during future droughts.

2010年，亚马逊盆地经历了异常干旱，这是五年来的第二次大干旱，这种模式与该地区未来气候的一些预测非常相似。这是因为大多数气候模型预测旱季强度会增加，而且作为全球气候变化的结果，未来世纪的气温都会上升。无论是否已经涉及长期气候变化，当前的事件都可以帮助我们评估潮湿森林，落叶林和稀树草原生态系统和物种对干燥的反应，从而帮助评估亚马逊气候干燥的潜在影响规模。我们的团队在该地区有一个大型的地面样本网络，因为这些样本是标准化的，所以它们代表了测量干旱实际影响的绝佳机会。我们已经在2005年的严重干旱中做到了这一点（当时被描述为“世纪干旱”，但今年的程度超过了这一点）。在本提案中，我们将重点放在亚马逊南部边缘的研究点上，该地区受到2010年干旱的严重影响。这一大片地区是亚马逊湿润森林物种、落叶物种和稀树草原之间的“紧张地带”，不同的植被类型有时在同一地点相邻。在这里，我们有30个永久性的地块，所以我们能够第一次测量在这个森林/稀树草原混合区对不同物种和植被形成的地面影响。这一点很重要，因为预计在这些生态紧张的地区，将首先观察到长期的植被变化，这些高多样性和高碳储量的地区可能会显著影响区域碳排放。我们计划采取以下措施：1）重新确定亚马逊南部30个地块，以记录树木生长和植被生产力。2）重新种植近500棵树，我们在干旱前测量了它们的结构细节，以评估干旱是否改变了它们。3）安装高精度测量工具（“测树仪”）对关键物种的树木进行监测，以便更好地监测未来的干旱4）分析从（1）和（2）收集的数据，以验证我们的假设：1. 2010年的干旱导致了森林而不是稀树草原的生物量碳损失。我们预计稀树草原比森林更有弹性，森林的反应反映了2005年的情况。2010年的干旱加速了树木的死亡，减少了森林的生长，但不是热带稀树草原。我们预计，当面临同样程度的干旱时，森林物种比稀树草原物种更敏感。森林和稀树草原地块，有最大的生物量损失和/或死亡率是那些最浅的土壤。我们预计土壤深度会影响干旱反应，较浅的土壤水分储备较少。在每一个立场，也发生在干燥地区的物种更耐旱比那些已经在其范围的干燥端。我们预计，树木面临的干旱风险与其地理分布有关，因此通常在潮湿气候中发现的物种将比其邻居对干旱更敏感。干旱敏感性的物种差异与结构性状的变异有关。我们预计，抗旱性更强的万年青树木将具有更保守的水力结构，例如更密集的木材。本研究的预期成果是：1）改进了过渡性亚马逊森林对干旱敏感性的量化。2）首次评估森林和稀树草原树木对干旱条件的不同敏感性。3）通过整合（1）和（2），更好地了解稀树草原取代“紧张区”森林的机会，甚至进入核心亚马逊森林，4）提高对抗旱生理基础和土壤条件重要性的认识。安装基础设施，使当地合作者能够评估未来干旱的影响。

项目成果

Collapse of ecosystem carbon stocks due to forest conversion to soybean plantations at the Amazon-Cerrado transition

亚马逊-塞拉多过渡期间森林转变为大豆种植园导致生态系统碳储量崩溃

• DOI: 10.1016/j.foreco.2018.01.038
• 发表时间: 2018
• 期刊: Forest Ecology and Management
• 影响因子: 3.7
• 作者: Bonini I

21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions.

• DOI: 10.1038/s41467-017-02771-y
• 发表时间: 2018-02-13
• 期刊: Nature communications
• 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

Evolutionary heritage influences Amazon tree ecology.

• DOI: 10.1098/rspb.2016.1587
• 发表时间: 2016-12-14
• 期刊: Proceedings. Biological sciences
• 作者: Coelho de Souza F;Dexter KG;Phillips OL;Brienen RJ;Chave J;Galbraith DR;Lopez Gonzalez G;Monteagudo Mendoza A;Pennington RT;Poorter L;Alexiades M;Álvarez-Dávila E;Andrade A;Aragão LE;Araujo-Murakami A;Arets EJ;Aymard C GA;Baraloto C;Barroso JG;Bonal D;Boot RG;Camargo JL;Comiskey JA;Valverde FC;de Camargo PB;Di Fiore A;Elias F;Erwin TL;Feldpausch TR;Ferreira L;Fyllas NM;Gloor E;Herault B;Herrera R;Higuchi N;Honorio Coronado EN;Killeen TJ;Laurance WF;Laurance S;Lloyd J;Lovejoy TE;Malhi Y;Maracahipes L;Marimon BS;Marimon-Junior BH;Mendoza C;Morandi P;Neill DA;Vargas PN;Oliveira EA;Lenza E;Palacios WA;Peñuela-Mora MC;Pipoly JJ 3rd;Pitman NC;Prieto A;Quesada CA;Ramirez-Angulo H;Rudas A;Ruokolainen K;Salomão RP;Silveira M;Stropp J;Ter Steege H;Thomas-Caesar R;van der Hout P;van der Heijden GM;van der Meer PJ;Vasquez RV;Vieira SA;Vilanova E;Vos VA;Wang O;Young KR;Zagt RJ;Baker TR
• 通讯作者: Baker TR

Pan-tropical prediction of forest structure from the largest trees

• DOI: 10.1111/geb.12803
• 发表时间: 2018-11-01
• 期刊: GLOBAL ECOLOGY AND BIOGEOGRAPHY
• 影响因子: 6.4
• 作者: Bastin, Jean-Francois;Rutishauser, Ervan;Zebaze, Donatien
• 通讯作者: Zebaze, Donatien

Drier tropical forests are susceptible to functional changes in response to a long-term drought

• DOI: 10.1111/ele.13243
• 发表时间: 2019-05-01
• 期刊: ECOLOGY LETTERS
• 影响因子: 8.8
• 作者: Aguirre-Gutierrez, Jesus;Oliveras, Imma;Malhi, Yadvinder
• 通讯作者: Malhi, Yadvinder