Do past fires explain current carbon dynamics of Amazonian forests?

过去的火灾能否解释亚马逊森林当前的碳动态？

• 批准号: NE/N011570/1
• 负责人: Ted Feldpausch
• 金额: $ 69.62万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN011570%2F1
• 关键词: Do; past; fires; explain; current

Amazon forests process and store large quantities of carbon in vegetation and soils. These forests, assumed to be mostly 'old-growth' and fire-free are exhibiting a remarkable feature-they are gaining the equivalent mass of a small car every year in aboveground biomass per hectare of forest (0.89 Mg/ha/yr). These gains are attributed to increasing atmospheric CO2, which has a fertilization effect on tree growth. However, fire in these 'old-growth' forests may be more recent than expected (in the last few centuries), and regrowth from fire together with soil charcoal-which has a fertility effect-may be contributing together with CO2 fertilisation to the observed increases in biomass in these apparently mature forests. Current understanding of drivers of these increases is limited by, (i) an unknown fire history of plots used to monitor change, and (ii) lack of information of how resource change affects these forests. The effects of pre-modern fire on forest regrowth and the gain have not been evaluated. Our pilot analysis of radiocarbon dated fire from soil charcoal indicates that even the wettest Amazon rainforest has burned, with forests considered to be 'old-growth' having burned within the last few centuries, and 70% of plots (n=70) containing visible soil charcoal fragments. Periodic drier climate and fire use by Native Americans before their populations collapsed ~450 years ago following Europeans colonisation may have resulted in a higher fire frequency than currently observed. Forest regrowth from these and more recent fires may still be occurring in forests considered to be 'undisturbed', e.g., some trees may grow to be 980 years old in central Amazonia, so that forest considered 'old-growth' may still be approaching equilibrium as long-lived trees mature following fire. Fire also produces soil pyrogenic carbon (PyC) as charcoal that is found in archaeological sites in terra preta soils and in upland soils across Amazonia far from evidence of human settlement. Soil PyC increases soil fertility on otherwise nutrient poor soils, and being resistant to decomposition, may have increased soil fertility across the Amazon. Pre-modern fire and soil PyC are therefore two important ingredients in understanding how Amazonian forests currently function.We will determine whether regrowth following past fire and soil PyC fertility effects in 'old-growth' permanent forest plots across Amazonia contributes to the observed carbon sink. We have developed a basin-wide network of on-the-ground sample plots, and because methods of measuring the forest with these are fully standardised even across nations they represent an excellent opportunity to measure the response of Amazon forest to historic fire and soil PyC.In permanent forest plots across the Amazon Basin our Objectives are:1) determine spatial patterns in 'time since last fire'; 2) determine soil PyC stocks, and how these are affected by climatic, edaphic conditions, and fire intensity;3) using results from (1) and (2), determine whether spatial patterns of productivity and carbon gains in aboveground tropical forest trees in Amazonia are consistent with regrowth from historical fire disturbance and by soil PyC acting as a soil fertility enhancerOur research will improve understanding of fire patterns across the Amazon for long-term forest plots (the same plots used to estimate the current carbon sink). We will provide a first quantification of: soil PyC stocks, basin-wide environmental drivers of soil PyC stocks, and whether soil fertility is greater where soil PyC levels are higher. This will be a first large-scale test of whether forest productivity, structure, and increases in carbon can be attributed to regrowth from historic fire and soil PyC fertility effects. The results are vital for conservation planning, to estimate the longevity of the carbon sink, and for policy such as Reducing Emissions from Deforestation and Degradation (REDD+).

亚马逊森林过程并在植被和土壤中存储大量碳。这些森林被认为主要是“旧生长”，没有火灾表现出了非凡的特征 - 每年每年在森林的地上生物量中，每年都会获得相当的小型汽车（0.89 mg/ha/yr）。这些收益归因于大气二氧化碳的增加，这对树木的生长具有受精作用。但是，这些“旧增长”森林中的火灾可能比预期的（在过去的几个世纪中）更新，而火灾和土壤木炭的再生长 - 具有生育能力，可以与二氧化碳受精一起为这些明显成熟的森林中观察到的生物群增长而贡献。当前对这些增加的驱动因素的理解受到（i）用于监测变化的地块的未知火史历史的限制，以及（ii）缺乏有关资源变化如何影响这些森林的信息。尚未评估前现代大火对森林再生和增益的影响。我们对泥土木炭的放射性碳二火的试点分析表明，即使是最潮湿的亚马逊雨林也已经燃烧，在过去的几个世纪内，森林被认为是“旧生长”的，其中70％的地块（n = 70）含有可见的土壤木炭碎片。在欧洲人的殖民地殖民地倒塌之前，美国原住民的种群崩溃之前，周期性的枯燥的气候和消防量可能会导致火灾频率更高。这些被认为是“不受干扰”的森林可能仍会发生森林再生。火还生产土壤中热源碳（PYC）作为木炭，在Terra Preta土壤中的考古遗址和亚马逊地区的高地土壤中发现，远非人类居民的证据。土壤PYC会增加养分贫困土壤的土壤生育能力，并且对分解具有抗性，可能会增加整个亚马逊的土壤肥力。因此，前现代的火和土壤PYC是了解亚马逊森林当前如何运作的两种重要成分。我们将确定在过去的火和土壤PYC生育能力后，在整个亚马逊群岛的“老增长”永久性森林地块中是否有助于观察到的碳汇。我们已经建立了一个盆地范围的样品图网络，并且由于用这些森林测量森林的方法甚至在各个国家中都完全标准化，所以它们代表了一个极好的机会，可以衡量亚马逊森林对历史悠久的火灾和土壤pyc的反应。 2）确定土壤PYC库存，以及它们如何受到气候，edaphic条件和火力强度的影响； 3）使用（1）和（2）的结果，确定在地上热带热带林中的生产力和碳增长的空间模式是否与亚马逊地区的热带热带林木中的碳增长相关，这与历史火灾的重新生长一致，以使土壤肥沃的森林对土壤的培训的培训持续增强，使得土壤肥沃的森林疗法的范围越来越改善，这是土壤肥沃的范围。 （用于估计当前碳汇的相同图）。我们将提供：土壤PYC库存，盆地范围内的土壤PYC库存的环境驱动因素，以及土壤PYC水平较高的土壤生育能力是否更大。这将是对森林生产率，结构和碳的增加是否可以归因于历史火灾和土壤PYC生育能力的再生的第一个大规模检验。结果对于保护计划，估计碳汇的寿命以及诸如减少森林砍伐和退化的排放（REDD+）等政策至关重要。

项目成果

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

Assessing MODIS Vegetation Continuous Fields tree cover product (collection 6): performance and applicability in tropical forests and savannas

评估 MODIS Vegetation Continuous Fields 树木覆盖产品（集合 6）：热带森林和稀树草原的性能和适用性

• DOI: 10.5194/bg-2020-460
• 发表时间: 2021
• 作者: Adzhar R

Climate defined but not soil-restricted: the distribution of a Neotropical tree through space and time

• DOI: 10.1007/s11104-021-05202-6
• 发表时间: 2021-11
• 期刊: Plant and Soil
• 影响因子: 4.9
• 作者: F. Alvarez;P. Morandi;B. H. Marimon‐Junior;Reginal Exavier;Igor Araújo;Lucas H. Mariano;A. Muller;T. Feldpausch;B. Marimon

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

Representation of disturbance in the Joint UK Land Environment Simulator Vn4.8 (JULES)

• DOI: 10.5194/gmd-2018-149
• 发表时间: 2018-07
• 期刊: Geoscientific Model Development Discussions
• 作者: Chantelle Burton;R. Betts;M. Cardoso;T. Feldpausch;A. Harper;C. Jones;D. Kelley;E. Robertson;A. Wiltshire