Artigo

Highly reactive light-dependent monoterpenes in the Amazon

Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including...

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Autor principal: Jardine, Angela B.
Outros Autores: Jardine, Kolby J., Fuentes, José D., Martin, Scot T., Martins, Giordane Augusto, Durgante, Flávia Machado, Carneiro, Vilany Matilla Colares, Higuchi, Niro, Manzi, Antônio Ocimar, Chambers, Jeffrey Quintin
Grau: Artigo
Idioma: English
Publicado em: Geophysical Research Letters 2020
Assuntos:
Acesso em linha: https://repositorio.inpa.gov.br/handle/1/15904
Resumo:
Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) which accounted for an estimated 21% of total monoterpene composition yet 55% of the upper canopy monoterpene ozonolysis rate. All 12 monoterpenes showed a mixing ratio peak in the upper canopy, with three demonstrating subcanopy peaks in 7 of 11 profiles. Leaf level emissions of highly reactive monoterpenes accounted for up to 1.9% of photosynthesis confirming light-dependent emissions across several Amazon tree genera. These results suggest that highly reactive monoterpenes play important antioxidant roles during photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation via ozonolysis. © 2015. The Authors.