Home About us Contact
|
Home About us Contact | ||
|
|
||
Pinus Sylvestris L. (pinus + sylvestri_l)
Selected AbstractsPine mistletoe (Viscum album ssp. austriacum) contributes to Scots pine (Pinus sylvestris) mortality in the Rhone valley of SwitzerlandFOREST PATHOLOGY, Issue 5 2006M. Dobbertin Summary In recent years unusual high mortality of Scots pine (Pinus sylvestris) has been observed in the Swiss Rhone Valley. The exact causes, however, are not known. At a 2-ha monitoring plot, tree mortality and crown condition have been monitored since 1996. Between 1996 and 2004, 59% of the Scots pines died, most of them following the drought periods 1996,1998 and 2003,2004, while only 15% of the deciduous trees died. Crown transparency, needle discolouration, dead branch percentage, mistletoe (Viscum album ssp. austriacum) rating, Tomicus sp. shoot feeding, male flowering effect, tree stem diameter, crown shading and social tree class assessed in 1998 were used in a logistic regression model to predict tree mortality. Crown transparency, mistletoe rating and percentage of dead branches were found significant in the model and the probability of tree mortality increased with increasing rankings of these parameters. Needle discolouration could be used to substitute ,dead branch percentage' as predictor. While crown transparency increased with mistletoe rating, for trees in the same transparency class, trees with medium and heavy mistletoe infection were two to four times more likely to die than trees with no or only low mistletoe infection. For the surviving trees we found that trees with mistletoes showed a significantly higher increase in transparency in the year following a drought than trees without, while in a drought year the opposite was true. At the beginning of the observations no significant differences in transparency had been found between the trees with and without mistletoe. However, by the end of the observation period trees with mistletoe had significantly higher crown transparency. We conclude that mistletoe infection can be considered as both a predisposing factor for tree death, by increasing needle loss following drought and a contributing factor by increasing water stress during drought. Résumé Une forte mortalité des pins sylvestres (Pinus sylvestris) a été observée ces dernières années dans la vallée du Rhône en Suisse. Les causes exactes n'en sont pas connues. La mortalité des arbres et l'état des houppiers ont été suivis depuis 1996 dans une parcelle de 2 ha. Entre 1996 et 2004, 59% des pins sylvestres sont morts, la plupart après les périodes de sécheresse de 1996,98 et 2003,2004, comparéà 15% pour les feuillus. La transparence des houppiers, le jaunissement des aiguilles, le pourcentage de mortalité de branches, une note d'importance du gui (Viscum album ssp. austriacum), les attaques d'alimentation sur pousses par Tomicus sp., la floraison mâle, le diamètre du tronc, l'ombrage du houppier et le statut social des arbres, mesurés en 1998, ont été utilisés dans un modèle de régression logistique pour prédire la mortalité des arbres. La transparence des houppiers, le taux de gui et le pourcentage de branches mortes sont des variables significatives, dont l'augmentation est associée à une augmentation de la probabilité de mortalité des arbres. Le jaunissement des aiguilles pourrait être substituée à la mortalité des branches comme variable prédictrice. Tandis que la transparence des houppiers augmente avec le taux de gui, au sein de la même classe de transparence, les arbres avec une infestation de gui moyenne à forte ont une probabilité de mortalité 2 à 4 fois plus élevée que les arbres à infestation faible ou nulle. Chez les arbres survivants, on observe que les arbres porteurs de gui ont une augmentation plus forte de la transparence du houppier l'année suivant une sécheresse que les arbres sans gui, l'inverse étant vrai pendant une année sèche. La différence de transparence des houppiers entre arbres porteurs de gui et arbres sans gui n'était pas significative au début des observations, alors qu'à la fin de la période, les arbres avec gui ont une transparence plus forte. Nous concluons que l'infestation par le gui peut être considérée à la fois comme un facteur prédisposant à la mortalité, en augmentant la perte d'aiguilles après sécheresse, et un facteur contribuant, en augmentant le stress hydrique pendant la sécheresse. Zusammenfassung Seit einigen Jahren werden im Schweizer Rhonetal hohe Absterberaten der gemeinen Kiefer (Pinus sylvestris L.) beobachtet. Die genauen Ursachen sind bis jetzt unbekannt. Auf der zwei Hektar grossen langfristigen Waldökosystemfläche (LWF) Visp werden seit 1996 jährlich Absterberaten, Kronenverlichtung, Mistelbefall (Viscum album ssp. austriacum) und andere Symptome aufgenommen. Zwischen 1996 und 2004 sind 59% aller Föhren auf der Fläche abgestorben, die meisten nach den Trockenperioden 1996,98 und 2003,2004. Dagegen starben nur 15% der Laubbäume ab. Kronenverlichtung, Nadelverfärbung, Totast- und Totzweiganteil (als Indikatoren der Vitalität des Baumes), Mistelbefallsklasse, Triebabwurf durch Waldgärtner, männliche Blütenbildung, Stammdurchmesser, Kronenkonkurrenz und soziale Stellung, alle im Jahr 1998 erhoben, wurden in einer logistischen Regression zur Bestimmung der Absterbewahrscheinlichkeit auf Signifikanz getestet. Kronenverlichtung, Mistelbefallsklasse und Totastanteil waren in dem Model signifikant. Die Wahrscheinlichkeit des Absterbens stieg dabei mit ansteigender Kronenverlichtung, ansteigendem Mistelbefall und ansteigendem Totastanteil. Der Totastanteil konnte im Model durch die Nadelverfärbung ersetzt werden. Die Kronenverlichtung stieg mit dem Mistelbefall an. Bei gleicher Verlichtung starben jedoch Bäume mit mittlerem und starkem Mistelbefall zwei- bis viermal häufiger ab als Bäume ohne oder mit leichtem Mistelbefall. Von den überlebenden Bäumen zeigten solche mit Mistelbefall einen deutlichen Anstieg der Transparenz im Jahr nach Beginn der Trockenheit im Vergleich zu den Bäumen ohne Misteln, während im Jahr der Trockenheit das Umgekehrte der Fall war. Zu Beginn der Beobachtung ergaben sich keine signifikanten Unterschiede in der Kronentransparenz der überlebenden Bäume mit und ohne Misteln. Am Ende der Beobachtungsperiode wiesen jedoch die Bäume mit Misteln signifikant höhere Kronenverlichtungen auf. Wir schliessen daraus, dass die Misteln auf der einen Seite den Baum langfristig schwächen, indem sie zur Reduzierung der Nadelmasse führen und sie auf der anderen Seite während Trockenheit durch erhöhten Wasserstress zum vorzeitigen Absterben beitragen. [source] Distribution of early-arriving saproxylic beetles on standing dead Scots pine treesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2010í Foit 1The community composition of early-arriving saproxylic beetles on 80 standing and recently deceased Scots pine trees (Pinus sylvestris L.) was examined. 2In total, 34 species of saproxylic beetles were found, comprising at least four well-defined groups of species identified by correspondence analysis. 3Bark thickness, trunk/branch diameter and height above ground significantly affected community composition, with bark thickness being the most important factor. 4Overall, 13.7% of the variance in species composition was explained by section of the tree that was sampled, a variable that encompasses the three aforementioned parameters. [source] Preference,performance relationship and influence of plant relatedness on host use by Pityogenes chalcographus L.AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2009Coralie Bertheau Abstract 1Pityogenes chalcographus L. (Coleoptera: Scolytinae) causes damage in European coniferous forests, primarily on Picea abies L. Karst., but is also recorded on other native and exotic Pinaceae species. Estimating the adequacy between adult preference and larval performance of this beetle among its host-range, as well as the influence of plant taxonomic relatedness on these parameters, would provide useful information on the beetle's ability to shift onto novel hosts. 2Choice and no-choice assays were conducted under laboratory conditions. Adult preference and larval performance parameters among two native (Pinus sylvestris L. and Picea abies) and three exotic north American [Pinus contorta Dougl., Picea sitchensis (Bong.) Carr. and Pseudotsuga menziesii Mirbel (Franco)] conifer species were measured. 3Pityogenes chalcographus exhibited a significant positive relationship between preference and performance. Picea abies was both the preferred and the most suitable host species for larval development. The closest relative, P. sitchensis, was the second best choice in terms of preference and performance. Pseudotsuga menziesii occupied an intermediate position for both beetle preference and performance, and Pinus spp. were the least suitable hosts for beetle development. 4Adult preference and larval performance ranking among hosts provides little support to the plant taxonomic relatedness hypothesis. Taxonomic relatedness could play a role on the diet breadth, although only at a limited scale, within the genus Picea. At higher taxonomic levels, other factors such as bark thickness might be decisive. [source] Soil type and microtopography influencing feeding above and below ground by the pine weevil Hylobius abietisAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2005Göran Nordlander Abstract 1,The influence of soil type and microtopography on above and below ground feeding by adult pine weevils Hylobius abietis (L.) (Coleoptera: Curculionidae) was evaluated in a field experiment with enclosed weevil populations of known size. 2,Four soil treatments, each with a food source at the centre, were presented within each enclosure: (i) a flat surface with fine-grained, cultivated humus; (ii) a flat surface with sand; (iii) a conical mound of sand; and (iv) a conical pit in sand. The food source consisted of a stem section of Scots pine Pinus sylvestris L. extending both above and below ground. 3,The majority of feeding on the half buried stem sections occurred below ground; only 2.7% of the total bark area consumed was situated above ground. The variation over time in bark area consumed was not significantly associated with any of the tested weather factors. 4,The amount of feeding was 10-fold higher on food sources placed in fine-grained humus than those in areas of flat sand. 5,Less pine bark was consumed on mounds of sand than flat sand surfaces, and there was more feeding in sandy pits than on flat sand. These effects on feeding are explained by the observation that the weevils had difficulties climbing the sandy slopes (27° gradient). 6,We conclude that pine weevil damage to conifer seedlings can be considerably reduced by planting on mounds of pure mineral soil and that planting deeply in the soil increases the risk of damage. [source] Geographic variation in winter freezing susceptibility in the eggs of the European pine sawfly (Neodiprion sertifer)AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2005T. O. Veteli Abstract 1,The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera, Diprionidae), frequently defoliates Scots pine (Pinus sylvestris L.) forests in northern Europe. It overwinters as an egg. It has been proposed that the high egg mortality caused by low winter temperatures limits the occurrence of outbreaks to the southern part of Fennoscandia. 2,In this study, variation in freezing avoidance by egg supercooling between four Finnish populations (originating between latitudes 60°N and 69°N) of N. sertifer was tested by differential thermal analysis. Offspring of 20 females within each population were selected for the study. The freezing avoidance of parasitized eggs was also examined. 3,The northernmost Inari population was found to be the cold hardiest, and the southernmost (Hanko) was the least hardy population. The within-population variation between females was greatest in the population from Inari, and the next greatest in the one from Hanko. The inland populations in Eastern Finland had the smallest within-population variation in freezing avoidance. 4,The high variation in freezing avoidance of eggs will enable N. sertifer to adapt to the predicted climate change and to spread its distribution northwards. This may also change the risk for outbreaks in this area. Parasitized eggs froze at higher temperature than healthy eggs. This observation indicates that N. sertifer may experience reduced egg parasitism in certain winter climate conditions. [source] In-vitro anti-inflammatory activity of Pinus sylvestris and Plantago lanceolata extracts: effect on inducible NOS, COX-1, COX-2 and their products in J774A.1 murine macrophagesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2005E. Vigo Extracts of the plant species Pinus sylvestris L. and Plantago lanceolata L. have been used in traditional medicine for the treatment of certain respiratory diseases, but little is known about their precise effects and mechanisms of action. In this study, we investigated the effect of these plant extracts on the production of nitric oxide (NO) and prostaglandin E2, NO synthase (NOS) type II, cyclooxygenase-1 (COX-1) and COX-2 mRNA expression in the murine macrophage cell line J774A.1. We found that Pinus sylvestris and Plantago lanceolata extracts inhibited NO production in a concentration-dependent manner in this cell line, without obvious cytotoxic effects as tested by MTT assay. The Plantago lanceolata extract at all doses used, and the Pinus sylvestris extract at high doses, showed significant scavenging of NO radicals released by the NO donor PAPA-NONOate. Our data also show that pre-treatment with these extracts significantly inhibits inducible NOS (iNOS) mRNA production in this cell line, without affecting COX-1 mRNA expression. COX-2 mRNA levels and PGE2 levels induced by lipopolysaccharide/interferon-, were not modified upon pre-treatment with the extracts. Thus, our results suggest that the anti-inflammatory properties of Pinus sylvestris and Plantago lanceolata extracts may reflect decreased NO production, possibly due to inhibitory effects on iNOS gene expression or to NO-scavenging activity. [source] A new dihydroflavonol from Pinus sylvestris L.MAGNETIC RESONANCE IN CHEMISTRY, Issue 4 2005Jari Sinkkonen Abstract A novel dihydroflavonol, C-6,O-7 -dimethylaromadendrin, was isolated from a 70% aqueous acetone extract of pine (Pinus sylvestris L.) bark. Its structure was determined by high-resolution negative fast atom bombardment mass spectrometry and NMR spectroscopy. The complete assignment of proton and carbon signals was achieved by 2D NMR experiments: HSQC, HMBC, DQF-COSY and NOESY. Copyright © 2005 John Wiley & Sons, Ltd. [source] Assessing environmental and physiological controls over water relations in a Scots pine (Pinus sylvestris L.) stand through analyses of stable isotope composition of water and organic matterPLANT CELL & ENVIRONMENT, Issue 1 2007ELKE BRANDES ABSTRACT This study investigated the influence of meteorological, pedospheric and physiological factors on the water relations of Scots pine, as characterized by the origin of water taken up, by xylem transport as well as by carbon isotope discrimination (,13C) and oxygen isotope enrichment (,18O) of newly assimilated organic matter. For more than 1 year, we quantified ,2H and ,18O of potential water sources and xylem water as well as ,13C and ,18O in twig and trunk phloem organic matter biweekly, and related these values to continuously measured or modelled meteorological parameters, soil water content, stand transpiration (ST) and canopy stomatal conductance (Gs). During the growing season, ,18O and ,2H of xylem water were generally in a range comparable to soil water from a depth of 2,20 cm. Long residence time of water in the tracheids uncoupled the isotopic signals of xylem and soil water in winter. ,18O but not ,13C in phloem organic matter was directly indicative of recent environmental conditions during the whole year. ,18O could be described applying a model that included 18O fractionation associated with water exchange between leaf and atmosphere, and with the production of organic matter as well as the influence of transpiration. Phloem ,13C was assumed to be concertedly influenced by Gs and photosynthetically active radiation (PAR) (as a proxy for photosynthetic capacity). We conclude that isotope signatures can be used as effective tools (1) to characterize the seasonal dynamics in source and xylem water, and (2) to assess environmental effects on transpiration and Gs of Scots pine, thus helping to understand and predict potential impacts of climate change on trees and forest ecosystems. [source] Variable photosynthetic acclimation in consecutive cohorts of Scots pine needles during 3 years of growth at elevated CO2 and elevated temperaturePLANT CELL & ENVIRONMENT, Issue 5 2003E.-M. LUOMALA ABSTRACT In this experiment, the photosynthetic acclimation of successive needle cohorts of Scots pine were studied during 3 years of growth at elevated CO2 and temperature. Naturally regenerated Scots pine (Pinus sylvestris L.) trees were subjected to elevated CO2 concentration (+CO2, 700 p.p.m), elevated temperature (+T, ambient +2 to +6 °C) and to a combination of elevated CO2 and temperature (+CO2 + T) in closed-top chambers, starting in August 1996. Trees growing in chambers with ambient CO2 and ambient temperature served as controls (AmbC). Elevated CO2 influenced the dark reactions more than the light reactions of photosynthesis, as in the 1996 and 1997 cohorts the carboxylation capacity of Rubisco was reduced in the first and second year of exposure, but there was no consistent change in chlorophyll fluorescence. Net photosynthesis measured at growth concentration of CO2 was higher at +CO2 than at AmbC on only one measuring occasion, was generally lower at +T and was not changed at +CO2 + T. However, trees grown at +T tended to invest more nitrogen (N) in Rubisco, as Rubisco/chlorophyll and the proportion of the total needle N bound to Rubisco occasionally increased. The interaction of +CO2 and +T on Rubisco was mostly negative; consequently, in the second and third year of the experiment the carboxylation capacity decreased at +CO2 + T. In the 1996, 1997 and 1998 cohorts, the structural N concentration of needles was lower at +CO2 than at AmbC. Elevated CO2 and elevated temperature generally had a positive interaction on N concentration; consequently, N concentration in needles decreased less at +CO2 + T than at +CO2. At +CO2 + T, the acclimation response of needles varied between years and was more pronounced in the 1-year-old needles of the 1997 cohort than in those of the 1998 cohort. Thus, acclimation was not always greater in 1-year-old needles than in current-year needles. In the +CO2 + T treatment, elevated temperature had a greater effect on acclimation of needles than elevated CO2. [source] Use of Shrubs as Nurse Plants: A New Technique for Reforestation in Mediterranean MountainsRESTORATION ECOLOGY, Issue 2 2002Jorge Castro Abstract Common techniques currently used for afforestation in the Mediterranean basin consider the pre-existing vegetation (mainly shrubs) as a source of competition for trees, and consequently it is generally eliminated before planting. Nevertheless, it has been demonstrated that woody plants can facilitate the establishment of understory seedlings in environments that, like the Mediterranean area, are characterized by a pronounced dry season. In this study, we experimentally analyze the usefulness of shrubs as nurse plants for afforestation of two native conifers, Pinus sylvestris L. (Scots pine) and Pinus nigra Arnold (black pine). Two-year-old seedlings were planted in four microhabitats: (1) open interspaces without vegetation (which is the usual method used in afforestation programs), (2) under individuals of Salvia lavandulifolia, (3) under the north side of spiny shrubs, and (4) under the south side of spiny shrubs. Pine survival was remarkably higher when planted under individuals of the shrub S. lavandulifolia (54.8% for Scots pine, 81.9% for black pine) compared with open areas (21.5% for Scots pine, 56.8% for black pine; chi square, p < 0.05). The survival of both pines was also higher when planted on the north side of spiny shrubs, although the survival on the south side was similar to that found in open areas. In addition, pine growth was not inhibited when planted in association with shrubs. This pattern appears to result from the combination of abiotic conditions imposed by the presence of a nurse shrub, which leads to improvement in seedling water status and therefore reduced summer mortality by drought. The results show that the use of shrubs as nurse plants is a technique that offers both economic and ecological advantages, in terms of savings in labor and plant material and reduced and even negligible impact on the pre-existing vegetation. [source] Hierarchical Spatial Modeling of Additive and Dominance Genetic Variance for Large Spatial Trial DatasetsBIOMETRICS, Issue 2 2009Andrew O. Finley Summary This article expands upon recent interest in Bayesian hierarchical models in quantitative genetics by developing spatial process models for inference on additive and dominance genetic variance within the context of large spatially referenced trial datasets. Direct application of such models to large spatial datasets are, however, computationally infeasible because of cubic-order matrix algorithms involved in estimation. The situation is even worse in Markov chain Monte Carlo (MCMC) contexts where such computations are performed for several iterations. Here, we discuss approaches that help obviate these hurdles without sacrificing the richness in modeling. For genetic effects, we demonstrate how an initial spectral decomposition of the relationship matrices negate the expensive matrix inversions required in previously proposed MCMC methods. For spatial effects, we outline two approaches for circumventing the prohibitively expensive matrix decompositions: the first leverages analytical results from Ornstein,Uhlenbeck processes that yield computationally efficient tridiagonal structures, whereas the second derives a modified predictive process model from the original model by projecting its realizations to a lower-dimensional subspace, thereby reducing the computational burden. We illustrate the proposed methods using a synthetic dataset with additive, dominance, genetic effects and anisotropic spatial residuals, and a large dataset from a Scots pine (Pinus sylvestris L.) progeny study conducted in northern Sweden. Our approaches enable us to provide a comprehensive analysis of this large trial, which amply demonstrates that, in addition to violating basic assumptions of the linear model, ignoring spatial effects can result in downwardly biased measures of heritability. [source] | ||||||||||