Volatile organic compounds (VOC) variation in Croton floribundus (L.) Spreng. related to environmental conditions and ozone concentration in an urban forest of the city of São Paulo, São Paulo State, Brazil

Abstract

Volatile organic compounds (VOC) variation in Received: 12.09.2017; accepted: 8.03.2018 ABSTRACT -(Volatile organic compounds (VOC) variation in Croton fl oribundus (L.) Spreng. related to environmental conditions and ozone concentration in an urban forest of the city of São Paulo, São Paulo State, Brazil). Volatile organic compounds (VOC) are emitted by vegetation in response to different kinds of stress, such as herbivory, environmental conditions and air pollutants. The aim of this study was to identify the VOC emitted by seedlings of Croton fl oribundus (L.) Spreng. exposed to a polluted environment and analyze the relationship among classes of compounds emitted, ozone levels and changes in climate conditions. Two exposures were carried out, one in winter (June to August 2012) and another in summer (January to April 2013), in the Parque Estadual das Fontes do Ipiranga, city of São Paulo, São Paulo State, Brazil. We identifi ed 26 compounds that are grouped into oxygenates, aromatics, monoterpenes and sesquiterpenes. The emission of sesquiterpenes was inhibited in summer, while those of the oxygenated and aromatic compounds were induced. The emission of volatiles was correlated to ozone levels (AOT 40). Our results suggest that the levels of atmospheric ozone detected in the summer can increase the induction of oxygenates and reduce the emission of monoterpenes in C. fl oribundus plants. Keywords: abiotic factors, air pollutants, oxidative stress RESUMO -(Variação dos compostos orgânicos voláteis (COV) deCroton fl oribundus (L.) Spreng. às condições ambientais e concentração de ozônio em fl oresta urbana de São Paulo, SP, Brasil). Os compostos orgânicos voláteis (COV) são emitidos pela vegetação em resposta ao estresse, incluindo fatores como herbivoria, condições ambientais e poluentes aéreos. Os objetivos deste trabalho foram identifi car compostos orgânicos voláteis emitidos por plantas jovens de Croton fl oribundus (L.) Spreng. expostas em ambiente poluído e relacionar as classes dos compostos emitidos com os níveis de ozônio atmosférico e variações climáticas. Foram realizadas duas exposições em diferentes estações climáticas (inverno de 2012: junho a agosto e verão de 2013: janeiro a abril), no Parque Estadual das Fontes do Ipiranga, São Paulo, SP, Brasil. Foram identifi cados 26 compostos, agrupados em oxigenados, aromáticos, monoterpenos e sesquiterpenos. As emissões dos sesquiterpenos foram inibidas no verão, enquanto as dos oxigenados e aromáticos foram induzidas. Os voláteis foram relacionados com os níveis de ozônio (AOT 40). Os resultados sugerem que os níveis de ozônio atmosférico detectados no verão podem contribuir para aumentar a emissão dos compostos oxigenados e reduzir a emissão dos monoterpenos em plantas de C. fl oribundus. Palavras-chave: estresse oxidativo, fatores abióticos, poluentes atmosféricos

Amazonian biogenic volatile organic compounds under global change

“…The central Amazonia plume has been reported to significantly increase O 3 levels by 35% at 70 km downwind of Manaus, whereas NOx levels increased by <20% relative to remote areas, indicating the strong role of BVOC oxidation in forming O 3 , in areas where NOx levels have increased due to pollution (maxima of up to 6 ppb; Wei et al., 2019). Enhanced urban pollution and plumes from burning biomass alter BVOC emissions by inducing further emissions of highly reactive BVOCs (Bolsoni, de Oliveira, da Silva Pedrosa, & de Souza, 2018) and thus, altering the dynamics of natural aerosols, with an increase in SOAs formed by BVOC oxidation (Shrivastava et al., 2019). The burning of biomass can profoundly alter SOA composition, although increases in organic submicron particulate matter during the dry season are also due to increased BVOC emissions combined with reduced deposition (de Sá et al., 2019; Williams et al., 2016).…”