Search results for "Pinus pinaster"
showing 10 items of 22 documents
Assessment of MODIS imagery to track light-use efficiency in a water-limited Mediterranean pine forest
2012
Abstract Daily values of gross primary production ( GPP ) derived from an eddy-covariance flux tower have been used to analyze the information content of the MODIS Photochemical Reflectance Index ( PRI ) on the light-use efficiency ( e ). The study has been conducted in a Mediterranean Pinus pinaster forest showing summer water stress. Advanced processing techniques have been used to analyze the effect of various external factors on e and PRI temporal variations. The intra-annual correlation between these two variables has been found to be mostly attributable to concurrent variations in sun and view zenith angles. The PRI has been normalized from these angular effects ( NPRI ), and its abil…
N transport in the Hebeloma cylindrosporum – Pinus pinaster ectomycorrhizal association
2007
International audience; Studies of nitrogen metabolism in ectomycorrhizas have demonstrated that the fungal symbiont plays a fully integrated role in plant root metabolism and participates actively in the assimilation and transfer of newly absorbed nitrogen compounds by transferring amino acids. In symbiotic associations, such as mycorrhizas, location of the symbiosis ensures that mycelial growth of the fungus into soil provides access to nutrients of the soil solution. Changes in the distribution and activity of membrane-bound transport proteins in response to symbiotic interactions need to be investigated. In recent years several genes from H. cylindrosporum and P. pinaster, putatively in…
Previous fire occurrence, but not fire recurrence, modulates the effect of charcoal and ash on soil C and N dynamics in Pinus pinaster Aiton forests.
2021
Abstract Understanding the effects of fire history on soil processes is key to characterise their resistance and resilience under future fire events. Wildfires produce pyrogenic carbonaceous material (PCM) that is incorporated into the soil, playing a critical role in the global carbon (C) cycle, but its interactions with soil processes are poorly understood. We evaluated if the previous occurrence of wildfires modulates the dynamic of soil C and nitrogen (N) and microbial community by soil ester linked fatty acids, after a new simulated low-medium intensity fire. Soils with a different fire history (none, one, two or three fires) were heat-shocked and amended with charcoal and/or ash deriv…
Maritime Pine Pinus Pinaster Aiton
2018
Maritime pine (Pinus pinaster Aiton) is the most abundant conifer in the Mediterranean basin. Currently, maritime pine is considered to be a model conifer species for study of the adaption responses to drought stress from a genomics approach. In this context, the availability of protocols that allow not only mass vegetative propagation of selected families or genotypes, but also facilitate the functional analyses needed to verify and further to study the effects of candidate genes are necessary. Here we describe an improved protocol to generate maritime pine plants through somatic embryogenesis from immature megagametophytes. Accurate procedures for explant preparation, somatic embryo induc…
Distribution of Δ5-olefinic acids in the triacylglycerols fromPinus koraiensisandPinus pinasterseed oils
1996
Purified triacylglycerols (TAG) fromPinus koraiensis andP. pinaster seed oils, which are interesting and commercially available sources of Δ5-olefinic acids (i.e.,cis-5,cis-9,cis-12 18:3 andcis-5,cis-11,cis-14 20:3 acids) were fractionated by reversed-phase high-performance liquid chromatography, and each fraction was examined by capillary gas-liquid chromatography for its fatty acid composition. A structure could be assigned to more than 92% of TAG from both oils. In both instances, ca. 48% of the TAG were shown to contain at least one δ5-olefinic acid. In the great majority of TAG, our data showed that there is only one molecule of δ5-olefinic acid per molecule of TAG. This is compatible …
Evaporation from soils of different texture covered by layers of water repellent and wettable soils
2020
Water repellent soils are able to channel water deep into the soil profile by fingered flow, minimising water storage in the water repellent top layer where water is most susceptible to evaporation. To date, the effect of water repellent or wettable surface layer on evaporation from wet sublayer has only been reported for coarse materials, and an increase in water repellency led to a greater delay in water evaporation. The objective of this study was to assess the effect of water repellent vs. wettable top layers with different thickness on water evaporation from coarse and fine texture subsoils that were pre-moistened. Clay loam soil samples were taken from Pinus pinaster woodland of Ciavo…
Isolation and characterization of N transporters putatively involved in the Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizal association
2007
International audience; Studies of nitrogen metabolism in ectomycorrhizas have demonstrated that the fungal symbiont plays a fully integrated role in plant root metabolism and participates actively in the assimilation and transfer of newly absorbed nitrogen compounds by transferring amino acids. In symbiotic associations, such as mycorrhizas, location of the symbiosis ensures that mycelial growth of the fungus into soil provides access to nutrients in the soil solution. Changes in the distribution and activity of membrane-bound transport proteins in response to symbiotic interactions need to be investigated. In recent years several genes from H. cylindrosporum and P. pinaster, putatively in…
New Approaches to Optimize Somatic Embryogenesis in Maritime Pine
2019
Maritime pine (Pinus pinaster Aiton) is a coniferous native of the Mediterranean basin. Because of its adaptability to a wide range of environmental conditions, the species have become a model for studies in coniferous forest management and functional genomics. Somatic embryogenesis (SE) has been so far, the preferred biotechnological strategy for maritime pine breeding programs initiated at the middle-end of the 20th century. To overcome the limitations of the induction and maturation phases in maritime pine SE, we analyzed the possible maternal influence on the embryogenic capability of megagametophytes from controlled crosses, as well as the effect of the temperature and water availabili…
Mid-Holocene vegetation dynamics in the Tejo River estuary based on palaeobotanical records from Ponta da Passadeira (Barreiro-Setúbal, Portugal)
2014
This paper presents the results of pollen and charcoal analyses carried out in the sedimentary formation of Ponta da Passadeira, south of the Tejo River estuary, Portugal. The data provide information regarding the evolution of the coastline and ecosystem of the estuary during the mid and late Holocene. The study focuses on a group of upright woody fossilized tree remains that, together with those identified earlier by Garcia-Amorena et al. (2007), form part of the fossil forest of Ponta da Passadeira. Eight remains were identified as Pinus pinaster, four as Pinus pinea and one as Pinus sp. Two specimens of these species were dated to 6523 and 5805 cal. a BP. Pollen analysis was undertaken …
Extent and persistence of soil water repellency induced by pines in different geographic regions
2018
The extent (determined by the repellency indices RI and RIc) and persistence (determined by the water drop penetration time, WDPT) of soil water repellency (SWR) induced by pines were assessed in vastly different geographic regions. The actual SWR characteristics were estimated in situ in clay loam soil at Ciavolo, Italy (CiF), sandy soil at Culbin, United Kingdom (CuF), silty clay soil at Javea, Spain (JaF), and sandy soil at Sekule, Slovakia (SeF). For Culbin soil, the potential SWR characteristics were also determined after oven-drying at 60°C (CuD). For two of the three pine species considered, strong (Pinus pinaster at CiF) and severe (Pinus sylvestris at CuD and SeF) SWR conditions we…