Jürgen W, Einhard K, Kiendler-Scharr A, Mentel T, Tillmann R, Hoffmann T, Hohaus T, Llusià J, Dal Maso M, Peñuelas J, Spindler C, Rudich Y, Uerlings R (2010) Yields of SOA formation from oxidation of different BVOC . IAC International Aerosol Conference Heklsinki proceedings.
Pandolfi M, Querol X, Alastuey X, Jimenez JL, Pey J, Cusack M, Reche C, Amato F, Artiñano B, Baldasano JM, Burkhart J, Hansel A, Jorba O, Lorente J, Mohr C, Moreno T, Nemitz E, Peñuelas J, Seco R, Filella I, Llusià J, Sicard M, Viana M (2010) An Overview of the DAURE Campaign: Aerosols Emissions and Evolution in the Western Mediterranean Basin. Geophysical Research Abstracts. Vol. 12, EGU2010-1202General Assembly proceedings.
Peñuelas J, Filella I, Estiarte M, Ogaya R, Llusià J, Sardans J, Jump A, Curiel J, Carnicer J, Rutishauser T, Rico L, Keenan T, Garbulsky M, Coll M, Díaz de Quijano M, Seco R, Rivas-Ubach A, Silva J, Boada M, Stefanescu C, Lloret F, Terradas J (2010) Impactes, vulnerabilitat i retroalimentacions climàtiques als ecosistemes terrestres catalans. A: Llebot E. (ed). Segon informe sobre el canvi climàtic a Catalunya. Institut d'Estudis Catalans i Generalitat de Catalunya. pp. 373-407.
Llusià J., Peñuelas J., Ogaya R., Alessio G. (2010) Annual and seasonal changes in foliar terpene content and emission rates in cistus albidus L. submitted to soil drought in Prades Forest (Catalonia, NE Spain). Acta Physiologiae Plantarum. 32: 387-394.EnllaçDoi: 10.1007/s11738-009-0416-y
We measured the gas exchange and foliar terpene concentrations and terpene emission rates of Cistus albidus throughout the seasons of two annual periods (2003 and 2005) of contrasting precipitations (900 vs. 500 mm) and in response to experimental drought in a Mediterranean forest of southern Catalonia. C. albidus showed a typical seasonal oscillation of photosynthetic rates and stomatal conductance. Maximum photosynthetic activity appeared in the spring of the first year of the study and minimum ones in both summers. Net photosynthetic rates and stomatal conductance tended to decrease with drought treatment. In the first year, Cistus albidus presented maximum values of stored terpenes in autumn and winter and minimum values in spring and summer. Average concentrations in the first year were 154 and 96 μg g-1 dry matter (d.m.) for control and drought, respectively. Average concentrations in the second year were higher, 339 and 263 μg g-1 (d.m.) for control and drought, respectively. The most abundant terpene was zingiberene, followed by aromadendrene, germacrene, (-)-α-cedrene, and sesquiphel-landrene. The drought treatment tended to decrease terpene content, but not significantly. Considering all the treatments together, total terpene emissions ranged between practically 0 (spring 2003) to 9 μg g-1 (d.m.) h-1 (winter 2003). In the second year, total terpene emission rates decreased 39% in control plants, and 29% in drought plants. Significant seasonal differences in emission rates were found. Total emission rates tended to be higher in the drought treatment, especially in spring and autumn. These results help for a better understanding of the behavior of plant volatiles in Mediterranean conditions interannualy and seasonally, an issue of great interest for forest flammability and atmospheric chemistry. © Franciszek Górski Institute of Plant Physiology.
Llusià J., Peñuelas J., Sardans J., Owen S.M., Niinemets Ü. (2010) Measurement of volatile terpene emissions in 70 dominant vascular plant species in Hawaii: Aliens emit more than natives. Global Ecology and Biogeography. 19: 863-874.EnllaçDoi: 10.1111/j.1466-8238.2010.00557.x
Aim Alien plant invasion is prominent in the Hawaiian Islands. There are many factors involved in invader success. To date, there is a general lack of information about one of them, which we aim to study here: the terpene emission capacity of both Hawaiian native and alien plants.Location Oahu (Hawaii).Methods We screened 35 alien and 35 native dominant plant species on Oahu Island for monoterpene emissions. The emission rates were measured from field-grown plants under standardized conditions of temperature and quantum flux density in the laboratory.Results The emission rates of total terpenes ranged from 0 μg g-1 h-1 to 55 μg g-1 h-1, and altogether 15 different terpenes were emitted in detectable amounts by the overall set of species. A phylogenetic signal was observed for total terpene emissions. Total terpene emission rates were higher in aliens than in native species (12.8 ± 2.0 vs. 7.6 ± 1.9 μg g-1 h-1, respectively).Main conclusions The greater terpene emission capacity may confer protection against multiple stresses and may partly account for the success of the invasive species, and may make invasive species more competitive in response to new global change-driven combined stresses. These results are consistent with aliens coming from very diverse ecosystems with generally higher biotic and abiotic stress pressures, and having higher nutrient concentrations. On the contrary, these results are not consistent with the 'excess carbon' hypotheses. These results indicate changes in vegetation terpene emissions brought about by alien plant invasions. © 2010 Blackwell Publishing Ltd.
Paris C.I., Llusia J., Peñuelas J. (2010) Changes in monoterpene emission rates of quercus ilex infested by aphids tended by native or invasive lasius ant species. Journal of Chemical Ecology. 36: 689-698.EnllaçDoi: 10.1007/s10886-010-9815-1
The emission of volatile organic compounds (VOCs) depends on temperature and light. Other factors such as insect herbivory also may modify VOC emission. In particular, aphid feeding promotes the release of new compounds and changes the composition of plant volatile blends. Given that some aphids are tended by ants, we investigated whether ants change the emission of VOCs indirectly through attendance on aphids. The effect of Lachnus roboris aphids and two different tending ant species on terpene emission rates of 4-year-old holm oak (Quercus ilex) saplings was investigated during a field experiment. There were five treatments: saplings alone (T1), saplings infested with L. roboris aphids (T2), saplings infested with aphids tended by the local ant Lasius grandis (T3), those tended by small colonies of the invasive ant Lasius neglectus (T4), and those tended by large colonies of the same invasive ant species (T5). The infestation by L. roboris elicited the emission of Δ3-carene and increased the emission of myrcene and γ-terpinene. Terpene emissions were modified depending on the tending ant species. Attendance by the local ant L. grandis increased α and β-pinene and sabinene. Attendance by the invasive ant L. neglectus only decreased significantly the emission of myrcene, one of the major compounds of the Q. ilex blend. Aphid abundance decreased with time for all treatments, but there was no difference in aphid abundance among treatments. Total terpene emission rates were not correlated with aphid abundance. These results highlight that aphids and tending ants may change terpene emission rates, depending on the ant species. © 2010 Springer Science+Business Media, LLC.
Penuelas J., Sardans J., Llusià J., Owen S.M., Carnicer J., Giambelluca T.W., Rezende E.L., Waite M., Niinemets Ü. (2010) Faster returns on 'leaf economics' and different biogeochemical niche in invasive compared with native plant species. Global Change Biology. 16: 2171-2185.EnllaçDoi: 10.1111/j.1365-2486.2009.02054.x
Plant-invasive success is one of the most important current global changes in the biosphere. To understand which factors explain such success, we compared the foliar traits of 41 native and 47 alien-invasive plant species in Oahu Island (Hawaii), a location with a highly endemic flora that has evolved in isolation and is currently vulnerable to invasions by exotic plant species. Foliar traits, which in most cases presented significant phylogenetic signal, i.e. closely related species tended to resemble each other due to shared ancestry, separated invasive from native species. Invasive species had lower leaf mass per area and enhanced capacities in terms of productivity (photosynthetic capacity) and nutrient capture both of macro- (N, P, K) and microelements (Fe, Ni, Cu and Zn). All these differences remain highly significant after removing the effects of phylogenetic history. Alien-invasive species did not show higher efficiency at using limiting nutrient resources, but they got faster leaf economics returns and occupied a different biogeochemical niche, which helps to explain the success of invasive plants and suggests that potential increases in soil nutrient availability might favor further invasive plant success. © 2009 Blackwell Publishing Ltd.
Peñuelas J., Sardans J., Llusia J., Owen S.M., Silva J., Niinemets Ü. (2010) Higher Allocation to Low Cost Chemical Defenses in Invasive Species of Hawaii. Journal of Chemical Ecology. 36: 1255-1270.EnllaçDoi: 10.1007/s10886-010-9862-7
The capacity to produce carbon-based secondary compounds (CBSC), such as phenolics (including tannins) and terpenes as defensive compounds against herbivores or against neighboring competing plants can be involved in the competition between alien and native plant species. Since the Hawaiian Islands are especially vulnerable to invasions by alien species, we compared total phenolic (TP), total tannin (Tta), and total terpene (TT) leaf contents of alien and native plants on Oahu Island (Hawaii). We analyzed 35 native and 38 alien woody plant species randomly chosen among representative current Hawaiian flora. None of these CBSC exhibited phylogenetic fingerprinting. Alien species had similar leaf TP and leaf Tta contents, and 135% higher leaf TT contents compared with native species. Alien plants had 80% higher leaf TT:N leaf content ratio than native plants. The results suggest that apart from greater growth rate and greater nutrient use, alien success in Oahu also may be linked to greater contents of low cost chemical defenses, such as terpenes, as expected in faster-growing species in resource rich regions. The higher TT contents in aliens may counterbalance their lower investment in leaf structural defenses and their higher leaf nutritional quality. The higher TT provides higher effectiveness in deterring the generalist herbivores of the introduced range, where specialist herbivores are absent. In addition, higher TT contents may favor aliens conferring higher protection against abiotic and biotic stressors. The higher terpene accumulation was independent of the alien species origin, which indicates that being alien either selects for higher terpene contents post-invasion, or that species with high terpene contents are pre-adapted to invasiveness. Although less likely, an originally lower terpene accumulation in Hawaiian than in continental plants that avoids the increased attraction of specialist enemies associated to terpenes may not be discarded. © 2010 Springer Science+Business Media, LLC.
Sampedro L., Moreira X., Llusia J., Peñuelas J., Zas R. (2010) Genetics, phosphorus availability, and herbivore-derived induction as sources of phenotypic variation of leaf volatile terpenes in a pine species. Journal of Experimental Botany. 61: 4437-4447.EnllaçDoi: 10.1093/jxb/erq246
Oleoresin produced and stored in pine tree leaves provides direct resistance to herbivores, while leaf volatile terpenes (LVT) in the resin are also powerful airborne infochemicals. Resin concentration and profile show considerable spatial and temporal phenotypic variation within and among pine populations. LVT biochemistry is known to be under genetic control, and although LVT should be plastic to diverse abiotic and biotic environmental factors such as nutrient availability and herbivore attack, little is known about their relative contributions and interactive effects. The aim of this paper was to clarify whether reduced phosphorus availability could increase the LVT concentration and affect the expression of herbivore-derived induced defences, and how plasticity would contribute to the phenotypic variation of LVT. The constitutive and methyl-jasmonate (MeJa) induced LVT concentration and profile were analysed in 17 half-sib Pinus pinaster families growing under two levels of P-availability (complete and P-limited fertilization). Individual terpene concentrations showed large additive genetic variation, which was more pronounced in the control than in MeJa-induced pines. MeJa application did not affect the LVT concentration, but significantly modified the LVT profile by depleting the α-pinene content and reducing the sesquiterpene fraction. Low P-availability strongly reduced plant growth and foliar nutrient concentrations, but did not affect LVT concentration and profile, and did not interact with MeJa-induction. Results indicate a strong homeostasis of LVT concentration to P-availability, and minor changes in the LVT profile due to MeJa-induction. Genetic variation appears to be the main source of phenotypic variation affecting the LVT concentration in this pine species. © 2010 The Author.
Sardans J., Llusià J., Niinemets U., Owen S., Peñuelas J. (2010) Foliar Mono- and Sesquiterpene Contents in Relation to Leaf Economic Spectrum in Native and Alien Species in Oahu (Hawai'i). Journal of Chemical Ecology. 36: 210-226.EnllaçDoi: 10.1007/s10886-010-9744-z
Capacity for terpene production may confer advantage in protection against abiotic stresses such as heat and drought, and also against herbivore and pathogen attack. Plant invasive success has been intense in the Hawaiian islands, but little is known about terpene content in native and alien plant species on these islands. We conducted a screening of leaf terpene concentrations in 35 native and 38 alien dominant plant species on Oahu island. Ten (29%) of the 35 native species and 15 (39%) of the 38 alien species contained terpenes in the leaves. This is the first report of terpene content for the ten native species, and for 10 of the 15 alien species. A total of 156 different terpenes (54 monoterpenes and 102 sesquiterpenes) were detected. Terpene content had no phylogenetic significance among the studied species. Alien species contained significantly more terpenes in leaves (average ± SE = 1965 ± 367 μg g-1) than native species (830 ± 227 μg g-1). Alien species showed significantly higher photosynthetic capacity, N content, and lower Leaf Mass Area (LMA) than native species, and showed higher total terpene leaf content per N and P leaf content. Alien species, thus, did not follow the expected pattern of "excess carbon" in comparison with native species. Instead, patterns were consistent with the "nutrient driven synthesis" hypothesis. Comparing alien and native species, the results also support the modified Evolution of Increased Competitive Ability (EICA) hypothesis that suggests that alien success may be favored by a defense system based on an increase in concentrations of less costly defenses (terpenes) against generalist herbivores. © 2010 Springer Science+Business Media, LLC.
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