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Heijari J.,University of Eastern Finland | Heijari J.,Kotka Maritime Research Center | Blande J.D.,University of Eastern Finland | Holopainen J.K.,University of Eastern Finland
Environmental and Experimental Botany | Year: 2011

Feeding by the large pine weevil (Hylobius abietis L.) causes severe damage to the bark of Scots pine (Pinus sylvestris L.) seedlings. We measured photosynthesis, the emission of volatile organic compounds from intact and weevil-damaged bark and systemic emissions from undamaged foliage. Feeding damage did not affect photosynthesis. Monoterpenes dominated the emissions from the feeding site, although some sesquiterpenes were also emitted. Weevil feeding increased bark emission of monoterpenes by nearly 4-fold and sesquiterpenes by 7-fold. The influence of weevil damage on systemic monoterpene emissions from shoots was more profound. Several compounds were substantially induced, including linalool, β-phellandrene, limonene and 1,8-cineole. Sesquiterpenes contributed only 1.2% of the total foliage emission, but comprised eight different compounds including (E,. E)-α-farnesene, β-bourbonene and (E)-β-farnesene. The total emission of monoterpenes and sesquiterpenes from shoots was respectively 2.8-fold and 2.9-fold higher in the pine weevil damaged plants than the undamaged plants. As many of the induced compounds are highly reactive in the atmosphere and form organic aerosol particles, our results suggest that conifers damaged by insects could become a more important source of secondary organic aerosols than healthy trees. © 2011 Elsevier B.V. Source

Hao L.Q.,University of Eastern Finland | Romakkaniemi S.,University of Eastern Finland | Yli-Pirila P.,University of Eastern Finland | Joutsensaari J.,University of Eastern Finland | And 22 more authors.
Atmospheric Chemistry and Physics | Year: 2011

Biogenic volatile organic compounds (VOCs) are a significant source of global secondary organic aerosol (SOA); however, quantifying their aerosol forming potential remains a challenge. This study presents smog chamber laboratory work, focusing on SOA formation via oxidation of the emissions of two dominant tree species from boreal forest area, Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies), by hydroxyl radical (OH) and ozone (O 3). Oxidation of α-pinene was also studied as a reference system. Tetramethylethylene (TME) and 2-butanol were added to control OH and O3 levels, thereby allowing SOA formation events to be categorized as resulting from either OH-dominated or O3-initiated chemistry. SOA mass yields from α-pinene are consistent with previous studies while the yields from the real plant emissions are generally lower than that from α-pinene, varying from 1.9% at an aerosol mass loading of 0.69 μg m-3 to 17.7% at 26.0 μg m-3. Mass yields from oxidation of real plant emissions are subject to the interactive effects of the molecular structures of plant emissions and their reaction chemistry with OH and O3, which lead to variations in condensable product volatility. SOA formation can be reproduced with a two-product gas-phase partitioning absorption model in spite of differences in the source of oxidant species and product volatility in the real plant emission experiments. Condensable products from OH-dominated chemistry showed a higher volatility than those from O3-initiated systems during aerosol growth stage. Particulate phase products became less volatile via aging process which continued after input gas-phase oxidants had been completely consumed. © 2011 Author(s). Source

Kivimaenpaa M.,University of Eastern Finland | Magsarjav N.,University of Eastern Finland | Magsarjav N.,Mongolian University of Science and Technology | Ghimire R.,University of Eastern Finland | And 5 more authors.
Atmospheric Environment | Year: 2012

Resin-storing plant species such as conifer trees can release substantial amounts of volatile organic compounds (VOCs) into the atmosphere under stress circumstances that cause resin flow. Wounding can be induced by animals, pathogens, wind or direct mechanical damage e.g. during harvesting. In atmospheric modelling of biogenic VOCs, actively growing vegetation has been mostly considered as the source of emissions. Root systems and stumps of resin-storing conifer trees could constitute a significant store of resin after tree cutting. Therefore, we assessed the VOC emission rates from the cut surface of Scots pine stumps and estimated the average emission rates for an area with a density of 2000 stumps per ha. The experiment was conducted with trees of one Estonian and three Finnish Scots pine provenances covering a 1200 km gradient at a common garden established in central Finland in 1991.VOC emissions were dominated by monoterpenes and less than 0.1% of the total emission was sesquiterpenes. α-Pinene (7-92% of the total emissions) and 3-carene (0-76% of the total emissions) were the dominant monoterpenes. Proportions of α-pinene and camphene were significantly lower and proportions of 3-carene, sabinene, γ-terpinene and terpinolene higher in the southernmost Saaremaa provenance compared to the other provenances. Total terpene emission rates (standardised to +20 °C) from stumps varied from 27 to 1582 mg h -1 m -2 when measured within 2-3 h after tree cutting. Emission rates decreased rapidly to between 2 and 79 mg h -1 m -2 at 50 days after cutting. The estimated daily terpene emission rates on a hectare basis from freshly cut stumps at a cut tree density of 2000 per ha varied depending on provenance. Estimated emission ranges were 100-710 g ha -1 d -1 and 137-970 g ha -1 d -1 in 40 and in 60 year-old forest stands, respectively. Our result suggests that emission directly from stump surfaces could be a significant source of monoterpene emissions for a few weeks after logging in a Scots pine stand, but provenance properties strongly affect resin flow from root to stump surface. © 2012 Elsevier Ltd. Source

Semiz G.,Pamukkale University | Blande J.D.,University of Eastern Finland | Heijari J.,Kotka Maritime Research Center | Isik K.,Akdeniz University | And 2 more authors.
Plant Biology | Year: 2012

Plant defence can be induced by exposing plants to the plant hormone jasmonic acid (JA) or its volatile ester, methyl jasmonate (MeJA). Carrageenans (Carr) - sulphated d-galactans extracted from red algae - can also induce plant defences. In this study, the effects of exogenous MeJA and Carr application (concentration 300 and 12.7μmol, respectively) on volatile emissions from two widespread evergreen woody species, Pinus sylvestris (nine Turkish and one Finnish provenance) and Quercus ilex (Italian provenance) were investigated. We collected headspace samples from seedlings and analysed the quality and quantity of volatile compounds emitted by treated and control plants. In total, 19 monoterpenes, 10 sesquiterpenes, 10 green leaf volatiles (GLVs) and two aromatic compounds were emitted by P. sylvestris from all the provenances studied. Foliar MeJA application clearly affected the volatile profiles of trees from all the provenances. Effects of Carr were genotype specific. In Q. ilex, emissions of sesquiterpenes, GLVs and the homoterpene (E)-DMNT were all induced by MeJA application. However, emissions of most constitutively emitted monoterpenes were significantly reduced. Carr application also led to a significant reduction in monoterpene emissions, but without corresponding increases in other emissions. Our results indicate that exogenously applied MeJA and Carr can both significantly modify the volatile profiles of P. sylvestris and Q. ilex, but also that there are important provenance- and species-specific differences in the overall degree of elicitation and compositions of elicited compounds. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands. Source

Heijari J.,University of Eastern Finland | Heijari J.,Kotka Maritime Research Center | Nerg A.-M.,University of Eastern Finland | Holopainen J.K.,University of Eastern Finland | Kainulainen P.,University of Eastern Finland
Entomologia Experimentalis et Applicata | Year: 2010

Four-year-old Scots pine [Pinus sylvestris L. (Pinaceae)] seedlings were exposed to medium and severe drought stress for two consecutive years. The anatomical properties of drought-stressed Scots pine wood and their impact on the performance of destructive wood boring early instars of Hylotrupes bajulus L. (Coleoptera: Cerambycidae) were studied. Drought stress significantly decreased diameter of earlywood tracheids in both growing years and diameter of latewood tracheids after the second growing season only. Cell lumen area was significantly decreased by both medium and severe drought stress compared to well-watered controls. In addition, area of cell lumen was significantly smaller in severe drought than in medium drought treatment. The drought stress marginally increased the number of resin canals in the wood, but did not affect the size of resin canals either in wood or bark. The relative growth rate of xylophagous H. bajulus neonatal larvae was not significantly affected by drought stress during the 106-day feeding period on Scots pine wood blocks. The results show that although water availability was an important factor affecting the development and anatomy of wood cells, observed changes in wood characteristics did not affect the performance of early instars feeding on wood processed from drought-stressed young Scots pine seedlings. © 2010 The Authors. Entomologia Experimentalis et Applicata © 2010 The Netherlands Entomological Society. Source

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