Volatile organic compounds in the western Mediterranean basin: Urban and rural winter measurements during the DAURE campaign

Seco R., Penuelas J., Filella I., Llusia J., Schallhart S., Metzger A., Muller M., Hansel A. (2013) Volatile organic compounds in the western Mediterranean basin: Urban and rural winter measurements during the DAURE campaign. Atmospheric Chemistry and Physics. 13: 4291-4306.
Enllaç
Doi: 10.5194/acp-13-4291-2013

Resum:

Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, but little is known about the daily VOC mixing ratios in Mediterranean urban and natural environments. We measured VOC mixing ratios concurrently at an urban and a rural site during the winter DAURE campaign in the northeastern Iberian Peninsula, by means of PTR-MS at both locations: a PTR-Quad-MS at the urban site and a PTR-ToF-MS at the rural site. All VOC mixing ratios measured were higher at the urban site (e.g. acetaldehyde, isoprene, benzene, and toluene with averages up to 1.68, 0.31, 0.58 and 2.71 ppbv, respectively), with the exception of some short-chain oxygenated VOCs such as acetone (with similar averages of 0.7-1.6 ppbv at both sites). The average diurnal pattern also differed between the sites. Most of the VOCs at the urban location showed their highest mixing ratios in the morning and evening. These peaks coincided with traffic during rush hour, the main origin of most of the VOCs analyzed. Between these two peaks, the sea breeze transported the urban air inland, thus helping to lower the VOC loading at the urban site. At the rural site, most of the measured VOCs were advected by the midday sea breeze, yielding the highest daily VOC mixing ratios (e.g. acetaldehyde, isoprene, benzene, and toluene with averages up to 0.65, 0.07, 0.19, and 0.41 ppbv, respectively). Only biogenic monoterpenes showed a clear local origin at this site. In addition, the concentrations of fine particulate matter observed at both sites, together with the synoptic meteorological conditions and radio-sounding data, allowed the identification of different atmospheric scenarios that had a clear influence on the measured VOC mixing ratios. These results highlight the differences and relationships in VOC mixing ratios between nearby urban and rural areas in Mediterranean regions. Further research in other urban-rural areas is warranted to better understand the urban-rural influence on atmospheric VOC mixing ratios under different atmospheric conditions. © 2013 Author(s).

Llegeix més

Litter VOCs induce changes in soil microbial biomass C and N and largely increase soil CO 2 efflux

Asensio D., Yuste J.C., Mattana S., Ribas À., Llusià J., Peñuelas J. (2012) Litter VOCs induce changes in soil microbial biomass C and N and largely increase soil CO 2 efflux. Plant and Soil. 360: 163-174.
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Doi: 10.1007/s11104-012-1220-9

Resum:

Aims: We investigated the effects of volatile organic compounds (VOCs) emitted by pine litter, specifically terpenes, on soil microbial biomass carbon and nitrogen and heterotrophic soil respiration under different microclimatic scenarios of water availability and temperature. Methods: Soil in glass jars (0.6 L headspace) was exposed to pine needle litter, avoiding any physical contact between soils and litter. Treatments were subjected to two moisture levels, control and drought (20 % and 10 % gravimetric soil water content respectively) and to different temperatures (temperature response curve from 5 °C to 45 °C). Results: In control soils, exposure to litter was associated with a significant decrease in microbial biomass carbon and ninhydrin extractable organic nitrogen, and with a significant increase in heterotrophic respiration (up to 46 %) under optimum temperature (25 °C). Drought, on the other hand, restricted the effects of litter exposure on heterotrophic respiration but exposure to litter was associated with a significant increase in microbial biomass nitrogen. We did not detect significant overall microbial consumption of terpenes in this study. Conclusions: These results suggest either that other VOCs not measured in the study were being consumed and/or that VOCs emissions were triggering strong changes in the composition and functioning of soil microbial communities. More studies under field conditions are needed to assess the magnitude of litter VOCs effects on carbon and nitrogen cycles. © 2012 Springer Science+Business Media B.V.

Llegeix més

Effects of phosphorus availability and genetic variation of leaf terpene content and emission rate in Pinus pinaster seedlings susceptible and resistant to the pine weevil, Hylobius abietis

Blanch J.-S., Sampedro L., Llusià J., Moreira X., Zas R., Peñuelas J. (2012) Effects of phosphorus availability and genetic variation of leaf terpene content and emission rate in Pinus pinaster seedlings susceptible and resistant to the pine weevil, Hylobius abietis. Plant Biology. 14: 66-72.
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Doi: 10.1111/j.1438-8677.2011.00492.x

Resum:

We studied the effects of phosphorus fertilisation on foliar terpene concentrations and foliar volatile terpene emission rates in six half-sib families of Pinus pinaster Ait. seedlings. Half of the seedlings were resistant to attack of the pine weevil Hylobius abietis L., a generalist phloem feeder, and the remaining seedlings were susceptible to this insect. We hypothesised that P stress could modify the terpene concentration in the needles and thus lead to altered terpene emission patterns relevant to plant-insect signalling. The total concentration and emission rate ranged between 5732 and 13,995μg·g -1DW and between 2 and 22μg·g -1DW·h -1, respectively. Storage and emission were dominated by the isomers α- and β-pinene (77.2% and 84.2% of the total terpene amount amassed and released, respectively). In both resistant and susceptible families, P stress caused an increase of 31% in foliar terpene concentration with an associated 5-fold decrease in terpene emission rates. A higher terpene content in the leaves implies that the 'excess carbon', available under limiting growth conditions (P scarcity), is allocated to terpene production. Sensitive families showed a greater increase in terpene emission rates with increasing P concentrations, which could explain their susceptibility to H. abietis. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Llegeix més

Floral BVOC emissions in relation to floral rewards and visits of pollinators in 5 plant species of a Mediterranean shrubland.

Farré G, Filella I, Llusià J, Peñuelas J (2012) Floral BVOC emissions in relation to floral rewards and visits of pollinators in 5 plant species of a Mediterranean shrubland. BVOCs Gordon Conference, Biogenic Hydrocarbons & the atmosphere. Reaching across scales: from molecule to the globe. Bates College, Maine. June 24-29.

Plants warn each other of imminent danger.

Seco R, Filella I, Llusià J, Peñuelas J (2012) Plants warn each other of imminent danger. UABdivulga 02/2012

Interactive effects between UV radiation and low water availability on Laurus nobilis seedlings.

Bernal M, Verdaguer D, Badosa J, Abadía A, Llusià J, Nuñez-Oliveira E, Peñuelas J, Llorens L (2012) Interactive effects between UV radiation and low water availability on Laurus nobilis seedlings. COST UV4growth Cost-Action (http://www.ucc.ie/en/uv4growth/meetings/girona2012/details/) COST Action FA0906. UV-B radiation: A specific regulator of plant growth and food quality in a changing climate (UV4growth). Girona. Abril.

Second report on climate change in Catalonia

Llebot JE, Carnicer J, Curiel J, Coll M, Díaz de Quijano M, Estiarte M, Filella I, Garbulsky M, Jump A, Llusià J, Ogaya R, Peñuelas J, Rico L, Rivas-Ubach A, Rutishauser T, Sardans J, Seco R, Silva J, Stefanescu C, Terradas J (2012) Second report on climate change in Catalonia. Executive summary. Institut d'Estudis Catalans. Generalitat de Catalunya. pp. 1-36. ISBN9788499650975.

BVOCs in the plant-pollinator market and other applications of ecology to betytyerunderstand BVOC emissions in the environment.

Peñuelas J, Filella I, Farré G, Owen S, Primante C, Rodrigo A, Martín A, Bosch J, Seco R, Porcar A, Llusià J, Greenberg J, Harley P, Rapparini F, Estiarte M, Mejia-Chang M, Ogaya R, Ibañez J, Sardans J, Turnipseed A, Geron C, Duhl T, Facini O, Baraldi R, Rapparini F, Guenther A (2012) BVOCs in the plant-pollinator market and other applications of ecology to betytyerunderstand BVOC emissions in the environment. BVOCs Gordon Conference, Biogenic Hydrocarbons & the atmosphere. Reaching across scales: from molecule to the globe. Bates College, Maine. June 24-29. Key note invited speaker.

Contrasting winger and summer VOC mixing ratios at a Mediterranean forest site: the effect of local biogenic emissions.

Seco R, Penuelas J, Filella I, Llusia J, Ansel A (2012) Contrasting winger and summer VOC mixing ratios at a Mediterranean forest site: the effect of local biogenic emissions. BVOCs Gordon Conference, Biogenic Hydrocarbons & the atmosphere. Reaching across scales: from molecule to the globe. Bates College, Maine. June 24-29.

Volatile organic compounds in the Western Mediterranean Basin: urban and rural winter measurements during the DAURE campaign

Seco R, Peñuelas J, Filella I, Llusià J, Schallharts S, Metzger A, Müller M, Hansel A 2012 Volatile organic compounds in the Western Mediterranean Basin: urban and rural winter measurements during the DAURE campaign. Atmospheric and Physics Discussion 12: 30909-30950.

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