scholarly journals High latitude vegetation changes will determine future plant volatile impacts on atmospheric organic aerosols

Author(s):  
Jing Tang ◽  
Putian Zhou ◽  
Paul Miller ◽  
Guy Schurgers ◽  
Adrian Gustafson ◽  
...  

Abstract Strong, ongoing high latitude-warming is causing changes to vegetation composition and plant productivity, modifying plant emissions of Biogenic Volatile Organic Compounds (BVOCs). In the sparsely populated high latitudes, climatic feedbacks resulting from BVOCs as precursors of atmospheric aerosols could be more important than elsewhere on the globe. Here, we quantitatively assess the linkages between vegetation changes, BVOC emissions and secondary organic aerosol (SOA) under different climate scenarios and show that warming-induced vegetation changes determine the spatial patterns of BVOC impacts on SOA. The northward advances of boreal needle-leaved trees and shrubs result in an increase of up to 45% in regional SOA optical depth, causing a cooling feedback. In contrast, areas dominated by temperate broad-leaved trees show a large decline in monoterpene emissions and SOA formation, causing a warming feedback. We highlight the necessity of considering vegetation shifts when assessing radiative feedbacks on climate following the BVOC-SOA pathway.

Author(s):  
Hind A. A. Al-Abadleh

Extensive research has been done on the processes that lead to the formation of secondary organic aerosol (SOA) including atmospheric oxidation of volatile organic compounds (VOCs) from biogenic and anthropogenic...


2017 ◽  
Vol 17 (15) ◽  
pp. 9677-9696 ◽  
Author(s):  
Rocío Baró ◽  
Laura Palacios-Peña ◽  
Alexander Baklanov ◽  
Alessandra Balzarini ◽  
Dominik Brunner ◽  
...  

Abstract. The climate effect of atmospheric aerosols is associated with their influence on the radiative budget of the Earth due to the direct aerosol–radiation interactions (ARIs) and indirect effects, resulting from aerosol–cloud–radiation interactions (ACIs). Online coupled meteorology–chemistry models permit the description of these effects on the basis of simulated atmospheric aerosol concentrations, although there is still some uncertainty associated with the use of these models. Thus, the objective of this work is to assess whether the inclusion of atmospheric aerosol radiative feedbacks of an ensemble of online coupled models improves the simulation results for maximum, mean and minimum temperature at 2 m over Europe. The evaluated models outputs originate from EuMetChem COST Action ES1004 simulations for Europe, differing in the inclusion (or omission) of ARI and ACI in the various models. The cases studies cover two important atmospheric aerosol episodes over Europe in the year 2010: (i) a heat wave event and a forest fire episode (July–August 2010) and (ii) a more humid episode including a Saharan desert dust outbreak in October 2010. The simulation results are evaluated against observational data from the E-OBS gridded database. The results indicate that, although there is only a slight improvement in the bias of the simulation results when including the radiative feedbacks, the spatiotemporal variability and correlation coefficients are improved for the cases under study when atmospheric aerosol radiative effects are included.


2015 ◽  
Vol 12 (2) ◽  
pp. 527-547 ◽  
Author(s):  
C. L. Faiola ◽  
B. T. Jobson ◽  
T. M. VanReken

Abstract. The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC–MS–FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.


2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Ibrahim Taga ◽  
Christopher Q. Lan ◽  
Illimar Altosaar

This paper highlights the role of plant volatile organic compounds, found in essential oils, for the treatment of bacteria related inflammation. This report is focused on tea tree oil, particularly its main compound terpinen-4-ol. Analysis of the published literature shows that many essential oils have significant antibacterial, antifungal and anti-inflammatory effects. Some of their major components, such as terpinen-4-ol, act by inhibiting pro-inflammatory cytokine expression while stimulating production of anti-inflammatory cytokines. Such observations may be exploited to encourage biotherapy against mastitis. The use of synthetic antibiotics is being increasingly discouraged because their presence in dairy milk may have potential downstream effects on population health and the agri-food chain. In the context of inflammation and related mammalian responses, understanding the interplay between volatile organic compounds, especially terpinen-4-ol, and cytokines during bacteria related inflammation should clarify their mode of action to control mastitis.


2015 ◽  
Vol 12 (2) ◽  
pp. 236 ◽  
Author(s):  
Cristina Iuga ◽  
C. Ignacio Sainz-Díaz ◽  
Annik Vivier-Bunge

Environmental context The presence of air-borne mineral dust containing silicates in atmospheric aerosols should be considered in any exploration of volatile organic compound chemistry. This work reports the mechanisms, relative energies and kinetics of free-radical reactions with formic acid adsorbed on silicate surface models. We find that silicate surfaces are more likely to act as a trap for organic radicals than to have a catalytic effect on their reactions. Abstract Heterogeneous reactions of atmospheric volatile organic compounds on aerosol particles may play an important role in atmospheric chemistry. Silicate particles are present in air-borne mineral dust in atmospheric aerosols, and radical reactions can be different in the presence of these mineral particles. In this work, we use quantum-mechanical calculations and computational kinetics to explore the reaction of a hydroxyl free radical with a formic acid molecule previously adsorbed on several models of silicate surfaces. We find that the reaction is slower and takes place according to a mechanism that is different than the one in the gas phase. It is especially interesting to note that the reaction final products, which are the formyl radical attached to the cluster surface, and a water molecule, are much more stable than those formed in the gas phase, the overall reaction being highly exothermic in the presence of the surface model. This suggests that the silicate surface is a good trap for the formed formyl radical. In addition, we have noted that, if a second hydroxyl radical approaches the adsorbed formyl radical, the formation of carbonic acid on the silicate surface is a highly exothermic and exergonic process. The carbonic acid molecule remains strongly attached to the surface, thus blocking CO2 formation in the formic acid oxidation reaction. The spectroscopic properties of the systems involved in the reaction have been calculated, and interesting frequency shifts have been identified in the main vibration modes.


2017 ◽  
Author(s):  
Rocío Baró ◽  
Laura Palacios-Peña ◽  
Alexander Baklanov ◽  
Alessandra Balzarini ◽  
Dominik Brunner ◽  
...  

Abstract. The climate effect of atmospheric aerosols is associated to their influence on the radiative budget of the Earth due to direct aerosol-radiation interactions (ARI) and indirect effects, resulting from aerosol-cloud interactions (ACI). On-line coupled meteorology-chemistry models permit the description of these effects on the basis of simulated atmospheric aerosol concentrations, although there is still some uncertainty associated to the use of these models. In this sense, the objective of this work is to assess whether the inclusion of atmospheric aerosol radiative feedbacks of an ensemble of on-line coupled models improves the simulation results for maximum, mean and minimum temperature over Europe. The evaluated model outputs originate from EuMetChem COST Action ES1004 simulations for Europe, differing in the inclusion (or omission) of ARI and ACI in the various models. The case studies cover two important atmospheric aerosol episodes over Europe in the year 2010, a heat wave and forest fires episode (July–August 2010) and a more humid episode including a Saharan desert dust outbreak in October 2010. The simulation results are evaluated against observational data from E-OBS gridded database. The results indicate that, although there is only a slight improvement in the bias of the simulation results when including the radiative feedbacks, the spatio-temporal variability and correlation coefficients are improved for the cases under study when atmospheric aerosol radiative effects are included, especially for those areas closest to emissions sources of atmospheric aerosols.


Science ◽  
2017 ◽  
Vol 356 (6345) ◽  
pp. 1386-1388 ◽  
Author(s):  
Funmilayo Adebesin ◽  
Joshua R. Widhalm ◽  
Benoît Boachon ◽  
François Lefèvre ◽  
Baptiste Pierman ◽  
...  

Plants synthesize a diversity of volatile molecules that are important for reproduction and defense, serve as practical products for humans, and influence atmospheric chemistry and climate. Despite progress in deciphering plant volatile biosynthesis, their release from the cell has been poorly understood. The default assumption has been that volatiles passively diffuse out of cells. By characterization of aPetunia hybridaadenosine triphosphate–binding cassette (ABC) transporter, PhABCG1, we demonstrate that passage of volatiles across the plasma membrane relies on active transport.PhABCG1down-regulation by RNA interference results in decreased emission of volatiles, which accumulate to toxic levels in the plasma membrane. This study provides direct proof of a biologically mediated mechanism of volatile emission.


2016 ◽  
Vol 62 (10) ◽  
pp. 803-811 ◽  
Author(s):  
Roberto Arredondo Valdés ◽  
Juan C. Delgado Ortiz ◽  
Mariana Beltrán Beache ◽  
Julia Anguiano Cabello ◽  
Ernesto Cerna Chávez ◽  
...  

Huanglongbing (HLB) is the most destructive disease of citrus worldwide. Monitoring of health and detection of diseases in trees is critical for sustainable agriculture. HLB symptoms are virtually the same wherever the disease occurs. The disease is caused by Candidatus Liberibacter spp., vectored by the psyllids Diaphorina citri Kuwayama and Trioza erytreae. Electron microscopy was the first technique used for HLB detection. Nowadays, scientists are working on the development of new techniques for a rapid HLB detection, as there is no sensor commercially accessible for real-time assessment of health conditions in trees. Currently, the most widely used mechanism for monitoring HLB is exploration, which is an expensive, labor-intensive, and time-consuming process. Molecular techniques such as polymerase chain reaction are used for the identification of HLB disease, which requires detailed sampling and processing procedures. Furthermore, investigations are ongoing in spectroscopic and imaging techniques, profiling of plant volatile organic compounds, and isothermal amplification. This study recognizes the need for developing a rapid, cost-effective, and reliable health-monitoring sensor that would facilitate advancements in HLB disease detection. This paper compares the benefits and limitations of these potential methods for HLB detection.


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