Identification of volatile organic compounds and their sources driving ozone and secondary organic aerosol formation in NE Spain.

Volatile organic compounds (VOCs) play a crucial role in the formation of ozone (O) and secondary organic aerosol (SOA). We conducted measurements of VOC ambient mixing ratios during both summer and winter at two stations: a Barcelona urban background station (BCN) and the Montseny rural background station (MSY). Subsequently, we employed positive matrix factorization (PMF) to analyze the VOC mixing ratios and identify their sources.

The Latin America Early Career Earth System Scientist Network (LAECESS): addressing present and future challenges of the upcoming generations of scientists in the region.

Early career (EC) Earth system scientists in the Latin America and the Caribbean region (LAC) have been facing several issues, such as limited funding opportunities, substandard scientific facilities, lack of security of tenure, and unrepresented groups equality issues. On top of this, the worsening regional environmental and climatic crises call for the need for this new generation of scientists to help to tackle these crises by increasing public awareness and research. Realizing the need to converge and step up in making a collective action to be a part of the solution, the Latin America Early Career Earth System Scientist Network (LAECESS) was created in 2016.

Drought affects carbon partitioning into volatile organic compound biosynthesis in Scots pine needles.

The effect of drought on the interplay of processes controlling carbon partitioning into plant primary and secondary metabolisms, such as respiratory CO release and volatile organic compound (VOC) biosynthesis, is not fully understood. To elucidate the effect of drought on the fate of cellular C sources into VOCs vs CO , we conducted tracer experiments with CO and position-specific C-labelled pyruvate, a key metabolite between primary and secondary metabolisms, in Scots pine seedlings. We determined the stable carbon isotope composition of leaf exchanged CO and VOC.

Physiological responses of date palm (Phoenix dactylifera) seedlings to seawater and flooding.

In their natural environment along coast lines, date palms are exposed to seawater inundation and, hence, combined stress by salinity and flooding. To elucidate the consequences of this combined stress on foliar gas exchange and metabolite abundances in leaves and roots, date palm seedlings were exposed to flooding with seawater and its major constituents under controlled conditions. Seawater flooding significantly reduced CO assimilation, transpiration and stomatal conductance, but did not affect isoprene emission.

Heat Waves Change Plant Carbon Allocation Among Primary and Secondary Metabolism Altering CO Assimilation, Respiration, and VOC Emissions.

Processes controlling plant carbon allocation among primary and secondary metabolism, i.e., carbon assimilation, respiration, and VOC synthesis are still poorly constrained, particularly regarding their response to stress.

Human Breathable Air in a Mediterranean Forest: Characterization of Monoterpene Concentrations under the Canopy.

Monoterpenes have been identified as potential determinants of the human health effects induced by forest exposure. The present study characterizes the total monoterpene concentrations at nose height in a Mediterranean Holm oak forest located in North-East Iberian Peninsula during the annual emission peak (summer and autumn: June to November) using a Proton Transfer Reaction-Mass Spectrometry (PTR-MS). Results show a strong variability of the total monoterpene concentrations in season and daytime.

Heat stress increases the use of cytosolic pyruvate for isoprene biosynthesis.

The increasing occurrence of heatwaves has intensified temperature stress on terrestrial vegetation. Here, we investigate how two contrasting isoprene-emitting tropical species, Ficus benjamina and Pachira aquatica, cope with heat stress and assess the role of internal plant carbon sources for isoprene biosynthesis in relation to thermotolerance. To our knowledge, this is the first study to report isoprene emissions from P.

Real-time carbon allocation into biogenic volatile organic compounds (BVOCs) and respiratory carbon dioxide (CO2) traced by PTR-TOF-MS, 13CO2 laser spectroscopy and 13C-pyruvate labelling.

Our understanding of biogenic volatile organic compound (BVOC) emissions improved substantially during the last years. Nevertheless, there are still large uncertainties of processes controlling plant carbon investment into BVOCs, of some biosynthetic pathways and their linkage to CO2 decarboxylation at central metabolic branching points. To shed more light on carbon partitioning during BVOC biosynthesis, we used an innovative approach combining δ13CO2 laser spectroscopy, high-sensitivity proton-transfer-reaction time-of-flight mass spectrometry and a multiple branch enclosure system in combination with position-specific 13C-metabolite labelling.

Vehicular Emission Ratios of VOCs in a Megacity Impacted by Extensive Ethanol Use: Results of Ambient Measurements in São Paulo, Brazil.

The São Paulo Metropolitan Area (SPMA) is a megacity with 20 million people and over 8 million vehicles. Over the past decade a large increase in biofuel usage, more notably ethanol by light-duty vehicles, has made Brazil, and in particular São Paulo, a unique case worldwide. This study presents the first assessment of emission ratios of a selected group of volatile organic compounds (VOCs) relative to carbon monoxide (CO) under ambient conditions.

Emissions of putative isoprene oxidation products from mango branches under abiotic stress.

Although several per cent of net carbon assimilation can be re-released as isoprene emissions to the atmosphere by many tropical plants, much uncertainty remains regarding its biological significance. In a previous study, we detected emissions of isoprene and its oxidation products methyl vinyl ketone (MVK) and methacrolein (MACR) from tropical plants under high temperature/light stress, suggesting that isoprene is oxidized not only in the atmosphere but also within plants. However, a comprehensive analysis of the suite of isoprene oxidation products in plants has not been performed and production relationships with environmental stress have not been described.