8,031 research outputs found

    Ectomicorrizas presentes en la plantación trufera “Los Quejigares” (Soria)

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    En este trabajo se describen las ectomicorrizas presentes en 16 plantas de Quercus ilex L. subsp. ballota (Desf.) Samp. de 22 años, de la finca de 600 ha que gestiona AROTZ-CATESA en el término municipal de Villaciervos (Soria). Además se presentan los porcentajes de micorrización de las ectomicorrizas más interesantes. Este estudio se incluye dentro del proyecto LIFE 99 ENV/E/000356 “Revalorización de bosques productores de trufa: un ejemplo de gestión sostenible”. SUMMARY: This study describes the ectomycorrhiza occurring in 16 twenty-two years old seedlings of Quercus ilex L. subsp. ballota (Desf.) Samp., in the plot of 600 ha that AROTZ-CATESA manages in of Villaciervos (Soria). Mycorrhization percentages of the most interesting ectomycorrhiza are also reported. This study is included in the project LIFE 99 ENV/E/000356 "Truffled Mediterranean forest improvement: an example of sustanaible management”

    Quercirhiza quadratum: a revision of the characters and identity of the ad type ectomycorrhiza

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    The well-known AD type, described first by Giraud in 1988, is considered as a competitor in black truffle (Tuber melanosporum Vittad.) plantations. It has been mainly observed in T. melanosporum and T. magnatum Pico plantations in France and Italy. This ectomycorrhiza has always been observed on roots of oak (Quercus ilex L. and Q. faginea Lam.) and hazelnut (Corylus avellana L.) plantations with “burnt” areas around the trees, even in those that do not produce black truffle sporocarps, so it can create false expectations in young plantations. The AD type has also been described in nurseries, as a competitive ectomycorrhiza on seedlings inoculated with black truffle. In Spain, AD type has been detected in black truffle plantations and natural holm oak stands in Navarra, Soria, Huesca, Zaragoza, Teruel, Castellón and Valencia. In 2005, De Román & De Miguel, suggested that AD type could be a telephoroid type due to its anatomical and morphological characters. In 2006, Baciarelli-Falini et al. using molecular techniques identified this type as an Ascomycotina belonging to Pezizales. The detailed anatomical, morphological and molecular study of the AD type led to a description as Quercirhiza quadratum (Águeda et al. 2008). Based on the anatomical and morphological characters, the AD type belongs to the Ascomycotina. The presence of Woronin bodies on hyphal septa, and the sometimes slightly dissolved septa, are two typical characters of this group. The DNA sequences obtained from the AD types studied showed close similarities with members of Pyronemataceae and Sarcosomataceae (Pezizales). Both taxonomic groups correspond to the same AD type as found by Baciarelli Falini et al., (2006). One of the studied sequences showed a close identity (100% maximum identity, 84% coverage) with Trichophaea woolhopeia (Cooke & W. Phillips) Arnould, although records of this fungal species are scarce in the Iberian Peninsula

    Some thoughts about nonequilibrium temperature

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    The main objective of this paper is to show that, within the present framework of the kinetic theoretical approach to irreversible thermodynamics, there is no evidence that provides a basis to modify the ordinary Fourier equation relating the heat flux in a non-equilibrium steady state to the gradient of the local equilibrium temperature. This fact is supported, among other arguments, through the kinetic foundations of generalized hydrodynamics. Some attempts have been recently proposed asserting that, in the presence of non-linearities of the state variables, such a temperature should be replaced by the non-equilibrium temperature as defined in Extended Irreversible Thermodynamics. In the approximations used for such a temperature there is so far no evidence that sustains this proposal.Comment: 13 pages, TeX, no figures, to appear in Mol. Phy

    Characterization and identification of field ectomycorrhizae of Boletus edulis and Cistus ladanifer

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    Field ectomycorrhizae sampled under Boletus edulis and Cistus ladanifer have been characterized and described in detail based on standard morphological and anatomical characters. The described ectomycorrhiza has traits typical of Boletales: whitish with three differentiated plectenchymatous layers in the mantle in plan view forming ring-like structures and rhizomorphs with highly differentiated hyphae. The inflated, smooth cystidia-like clavate end cells on the surface of the rhizomorphs and their slightly twisted external hyphae are additional characterizing features. The Hartig net occupies 1 1/2 rows of cortical cells, partly reaching the endodermis. Not all hyphae have clamps. The identification of the fungal symbiont as B. edulis was confirmed by ITS rDNA sequence comparison between mycorrhizas and sporocarps. The singularity of this symbiotic association, as well as its ecological and practical implications, are discussed

    The ENSO signature in sea-surface temperature in the Gulf of California

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    We analyzed 21 years of sea-surface temperature satellite images to explore the spatial signature of the El Niño-Southern Oscillation signal in the Gulf of California. We used empirical orthogonal function analysis to extract the principal mode of the nonseasonal sea-surface temperature variability and compared it to the spatial signature of the Southern Oscillation Index. The first mode accounted for 80% of nonseasonal variability and its amplitude time series was significantly correlated to the Southern Oscillation Index (r = −0.58,P \u3c 0.01). The amplitude of this mode and its statistical relation to the El Niño is stronger during winter, which suggests that forcing of sea-surface temperature variability occurs through the disruption of the wind-driven upwelling corridor along the eastern coast due to El Niño-related atmospheric teleconnections. We also examined weekly time series of coastal sea-surface temperature coastal anomalies along the coast of North America, including the interior of the Gulf of California, during the strong 1997–98 El Niño. We found a poleward propagating signal that reached the mouth of the Gulf of California at the end of spring and continued its poleward propagation along the west coast of the peninsula slightly delayed; it also resulted in warming inside the Gulf of California. This observation may provide an explanation for the variable extension of the El Niño signature along the Pacific coast of North America

    Ectomycorrhizal status of a mature productive black truffle plantation

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    The truffle-plantation «Los Quejigares» was planted in 1971 by AROTZ-CATESA company. It is a 600 ha plot of Quercus ilexmycorrhizated with Tuber melanosporum at 1,250 m a.s.l. on calcareous soil. This plantation is the largest of the world and one of the eldest truffle-plantations of Spain and it is in full production. Knowledge of the mycorrhizal status of a mature black truffle plantation is significant for the improvement of truffle cultivation. Ectomycorrhizae were studied for knowing T. melanosporum persistence and diversity and abundance of other ectomycorrhizal types. Roots of 16 holmoaks were sampled, 12 trees produce truffle sporocarps and four did not. It was found a mean of about 35% of T. melanosporum ectomycorrhizae in the studied trees, being this significantly higher in the productive trees. Also, 105 more different ectomycorrhizal types were found. In spite of the high number of morphotypes found, it seems that they do not replace T. melanosporum, showing that there is a coexistence between species in the fungal community associated to the roots

    A novel free-fall reactor for (catalytic) pyrolysis of biomass and plastics

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    Caracterización de ectomicorrizas en encinares productores de trufa negra del noreste de Soria

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    Black truffle sporocarp production is determined, amongst many other factors, by an optimum mycorrhization degree in the roots of the host-tree. This process is triggered in balance with other fungal species that does not inhibit its sporocarp production. So, there is an ectomycorrhizal fungal community associated with the black truffle sporocarp productive host-trees that runs as any other living beings community, producing a certain fungal biodiversity and establishing connections in dynamic balance that will evolve. The absence of black truffle sporocarps production in some host-trees will be determined by its ectomycorrhiza absence, or because between the fungal community there are one or more species that inhibit this process or displace it. With the aim of study those topics, the ectomycorrhizae present in 23 adult holmoak trees (Quercus ilex subsp. ballota (Desf.) Samp.) of seven Tuber melanosporum Vittad. productive areas in the North-West of Soria (inner Spain) are characterized and quantified. During the spring and the autumn of 1999 and 2000, black truffle productive and non-productive holmoaks were studied following the global method (Verlhac et al., 1990, La truffe guide pratique). Ectomycorrhizal types were characterized following the guidelines of Agerer (1999). Tuber melanosporum, T. aestivum Vittad., T. brumale Vittad., Cenococcum geophylum Fr., Pisolithus arrhizus (Scop.) Rauscher, Cantharellus tubaeformis (Bull.) Fr., Hebeloma cf. sinapizans (Fr.) Sacc., Tomentella galzinii Bourdot, AD type, Cortinarius sp., Hebeloma sp. and Scleroderma sp. and many others Telephorales, Tuberales and Boletales ectomycorrhizal types were found. Tuber melanosporum mycorrhizae are present both in productive and non-productive hosttrees, as it happens for T. aestivum, while T. brumale ectomycorrhizae are only present in nonproductive holmoaks. The rest of identified ectomycorrhizal types are present in productive and non-productive host-trees
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