AmazonFACE: assessing the effects of increased atmospheric CO2 on the ecology of the Amazon Forest

• Grant number: 23/09046-5
• Support Opportunities: Research Projects - Thematic Grants
• Start date: March 01, 2025
• End date: February 28, 2030
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: David Montenegro Lapola
• Grantee: David Montenegro Lapola
• Host Institution: Centro de Pesquisas Meteorológicas e Climáticas Aplicadas à Agricultura (CEPAGRI). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Pesquisadores principais: Carlos Alberto Martinez y Huaman ; Marko Synésio Alves Monteiro ; Sara Adrian Lopez de Andrade ; Simone Aparecida Vieira ; Tomas Ferreira Domingues
• Associated researchers: Adriane Esquivel Muelbert ; Alan James Peixoto Calheiros ; Anete Pereira de Souza ; Anja Rammig ; Carlos Alberto Nobre Quesada ; Carolina Casagrande Blanco ; Cristina Maria Filipe Máguas da Silva Hanson ; Eiko Eurya Kuramae ; Gustavo Carvalho Spanner ; Juliana Schietti de Almeida ; Laynara Figueiredo Lugli ; Leonor Patricia Cerdeira Morellato ; Lucia Fuchslueger ; Maíra de Campos Gorgulho Padgurschi ; Márcio José Teixeira ; Nicola Gedney ; Pedro Luiz Pizzigatti Corrêa ; Peter Stoltenborg Groenendyk ; Lucy Rowland ; Richard James Norby ; Sami Ullah ; Silvia Ribeiro de Souza ; Simon Scheiter ; Thorsten Grams ; Tiago da Silva Jacaúna ; Tiago Ribeiro Duarte ; Vincent Gauci

Abstract

Tropical forests are one of the most important global carbon sinks, compensating a significant fraction of global anthropogenic CO2 emissions. Understanding what drives their capacity to absorb and store carbon in the future is of utmost importance. In addition to its key relevance for the global carbon and water cycles, biodiversity, and traditional human populations, the Amazon forest is also the only tropical region considered as a "tipping element" of the climate system. The ultimate impact of or recovery from threats occurring in the world's largest tropical forest such as deforestation, forest degradation, and namely climate change will strongly depend on the direct physiological response of the forest to elevated atmospheric CO2 (eCO2). Nevertheless, as of today, the lack of evidence on such response of tropical forests to eCO2 causes Earth system models to generally project that the impacts of climate change on the Amazon forest will be dampened by CO2 fertilization - which is largely hypothetical given our current knowledge. The best scientific method so far for assessing the responses of forest ecosystems to eCO2 is the Free-Air CO2 Enrichment (FACE) technology. But past forest FACE experiments have occurred only in temperate regions and never in high-biodiversity ecosystems. These previous FACE experiments showed that the lack of nutrients limits the ecosystem response to eCO2. This might be the case of the Amazon forest, given that phosphorus is a limiting soil-bound nutrient in at least 60% of the basin area. However, the hyper-diversity of plant species found in tropical forests prevents us from supposing that the results from past FACE experiments are readily applicable to the Amazon. In this thematic project we take advantage of the already funded (BRL$32million from Brazil's MCTI + BRL$30million from UK's FCDO) infrastructure of the AmazonFACE programme to investigate the following general question: How will rising atmospheric CO2 affect the ecology of the Amazon forest, its biogeochemistry, the biodiversity it harbors, and the ecosystem services it provides? This research effort will be split into 6 subprojects investigating (1) whether net carbon uptake will increase under eCO2 (carbon), and if so will the response be sustained during a 5 years time horizon, (2) if such enhanced carbon uptake translates into increased stand biomass, (3) whether the responses to eCO2 are constrained by soil nutrients, (4) changes in water fluxes, (5) representation of responses with trait-based vegetation modeling and (6) socio-environmental implications (via the use of the experiment results into public policies), led by scientists from UNICAMP and USP. A general budget of BRL$ 5.6 million + USD$778,000 is requested, to be executed in a period of 5 years. This project will benefit from comprehensive preliminary research efforts to implement and characterize the AmazonFACE experimental plots, including taxonomic and functional identification of the plant community, baseline field measurements of NPP and biomass, as well as preliminary modeling activities and socioenvironmental assessments. It also benefits from an existing network of international scientists from the UK, Germany and USA. The ultimate legacy expected from this research will be the reduction of key uncertainties that permeate vegetation, climate and Earth system models concerning the way the Amazon will respond to eCO2 and climate change. It will also represent a leapfrog for ecological assessments in Brazil, in terms of scope, complexity, scale and impact, clustering the training of about 40 grad and undergrad students, post-docs and technicians. (AU)