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PROPIEDADES MECANICAS EN FLEXION DE LA MADERA DE Pinus radiata, CRECIENDO EN UN SISTEMA SILVOPASTORAL: I: ELASTICIDAD Y RESISTENCIA
Ramírez V,Mauricio; Valenzuela H,Luis; Díaz S,Cristian;
Maderas. Ciencia y tecnología , 2001, DOI: 10.4067/S0718-221X2001000100004
Abstract: the effects of fertilization frequency and two stem heights on elasticity and strength in static bending (modulus of elasticity, stress at proportional limit and modulus of rupture) of pinus radiata wood, growing in a silvopastoral system were evaluated. twenty-seven trees were selected from three silvopastoral trials (nine trees per treatment) established at "tanumé" experimental center. destructive static bending test were realized according to astm d 143-94, the analysis of the variables was carried out using a nested design and the effects of variables were evaluated by analysis of variance (anova). according to the results, the fertilization frequency on the different physical and mechanical parameters that were evaluated did not have a significant effect. however, stem height had a significant effect on stress at proportional limit and modulus of rupture due to different average values of annual ring width and nominal density found at two different heights of the stem tree
PROPIEDADES MECANICAS EN FLEXION DE LA MADERA DE Pinus radiata, CRECIENDO EN UN SISTEMA SILVOPASTORAL: I: ELASTICIDAD Y RESISTENCIA BENDING MECHABICAL PROPERTIES OF Pinus radiata WOOD, GROWING IN A SILVOPASTORAL SYSTEM: I: ELASTICITY AND STRENGHT
Mauricio Ramírez V,Luis Valenzuela H,Cristian Díaz S
MADERAS : Ciencia y Tecnología , 2001,
Abstract: Se evaluaron, los efectos de la frecuencia de fertilización y de dos alturas en el fuste, sobre los parámetros de elasticidad y resistencia en flexión (módulo de elasticidad, esfuerzo en el límite proporcional y módulo de ruptura), de la madera de P. radiata creciendo en un sistema silvopastoral. Para tales objetivos, fueron muestreados 27 árboles provenientes de tres ensayos silvopastorales (9 árboles por tratamiento), establecidos en el Centro Experimental "Tanumé". Los ensayos destructivos de flexión estática fueron realizados de acuerdo con lo prescrito por la norma ASTM D 143-94, el dise o experimental aplicado fue anidado de efectos mixtos y el procesamiento de la información se realizó mediante análisis de varianza. Los resultados demostraron que la frecuencia de fertilización no tuvo un efecto significativo en los diferentes parámetros físicos y mecánicos evaluados. Sin embargo, la altura en el fuste, tuvo un efecto significativo en el esfuerzo en el límite proporcional y el módulo de ruptura, respuesta que fue explicada por las diferencias encontradas a diferentes alturas en los valores promedios del ancho de anillo de crecimiento y de la densidad nominal The effects of fertilization frequency and two stem heights on elasticity and strength in static bending (modulus of elasticity, stress at proportional limit and modulus of rupture) of Pinus radiata wood, growing in a silvopastoral system were evaluated. Twenty-seven trees were selected from three silvopastoral trials (nine trees per treatment) established at "Tanumé" Experimental Center. Destructive static bending test were realized according to ASTM D 143-94, the analysis of the variables was carried out using a nested design and the effects of variables were evaluated by analysis of variance (ANOVA). According to the results, the fertilization frequency on the different physical and mechanical parameters that were evaluated did not have a significant effect. However, stem height had a significant effect on stress at proportional limit and modulus of rupture due to different average values of annual ring width and nominal density found at two different heights of the stem tree
El monocultivo de pino radiata en el País Vasco: origen y claves de permanencia de un sistema de explotación contrario al desarrollo sostenible  [cached]
Ainz Ibarrondo, Ma José
Estudios Geográficos , 2008,
Abstract: The Basque Country has a great forestry assets; an important proportion of the forestry surface is occupied by the monoculture of radiata pine —Pinus radiata D. Don— with a silviculture lessive with environment. In this study, the origin of the actual forest practise is analysed and some reasons of its continuity although their incompatibility with sustainable development are exponed. El País Vasco dispone de un importante patrimonio forestal; sin embargo, una parte sustancial de los montes se dedican al monocultivo del pino radiata —Pinus radiata D. Don—, sometiéndose a una práctica silvícola muy agresiva desde el punto de vista ambiental. Este trabajo analiza el origen del actual forestalismo intensivo y plantea las claves que explican la permanencia de una gestión forestal incompatible con el desarrollo sostenible.
Soil bulk density and biomass partitioning of Brachiaria decumbens in a silvopastoral system
Paciullo, Domingos Sávio Campos;Castro, Carlos Renato Tavares de;Gomide, Carlos Augusto de Miranda;Fernandes, Priscila Beligoli;Rocha, Wadson Sebasti?o Duarte da;Müller, Marcelo Dias;Rossiello, Roberto Oscar Pereyra;
Scientia Agricola , 2010, DOI: 10.1590/S0103-90162010000500014
Abstract: shade in silvopastoral systems improves the thermal comfort of animals, but it may also affect the pasture productivity and can contribute to soil compaction in the shaded areas due to the increase in the number of animals looking for comfort. the effect of grazing at various distances from tree rows (under the tree canopy, at 6 and at 12 m away from the trees) on the soil bulk density and on the aerial and root biomass of brachiaria decumbens was evaluated in both the dry and the rainy seasons. the study was carried out on an orthic ferralsol in a randomized block design with two replications. tree rows were composed of eucalyptus grandis and acacia mangium species, and the paddocks were submitted to a rotational stocking management, using holstein (bos taurus) × zebu (bos indicus) heifers. the shade intensity in the pasture decreased with an increasing distance from the tree row. soil bulk density did not vary with the distance from the tree row, but varied seasonally, being greater in the rainy season (1.47 g cm-3) than in the dry season (1.28 g cm-3). green forage and root mass, expressed as dry matter, were lower under the tree canopy and were greater in the rainy season. there were decreases of 22.3 and 41.4% in the aerial and root biomasses, respectively, in the tree rows. the greatest shoot/root ratio for b. decumbens under moderate and intensive shading indicates a modification in the forage biomass allocation pattern that favours the aerial development in detriment of the root system.
Soil C/N influences the carbon flux and partitioning in control and fertilized mini-plots of Pinus radiata in New Zealand
Bown,Horacio E; Watt,Michael S; Clinton,Peter W; Mason,Euan G;
Ciencia e investigación agraria , 2011, DOI: 10.4067/S0718-16202011000200013
Abstract: patterns of carbon flux and partitioning were examined in highly stocked (40,000 stems ha-1) control and fertilized mini-plots of pinus radiata d. don at five sites, which covered a wide climatic and edaphic gradient on the south island of new zealand. the gross-primary productivity (gpp) and the partitioning of the gpp to the above- and below-ground productivity and respiration were determined using a carbon budget approach. all of the components of the gpp, the above-ground net primary productivity (anpp [r2 = 0.67, p ≤ 0.01]), above-ground plant respiration (apr [r2 = 0.66, p ≤ 0.01]), and total below-ground carbon flux (tbcf [r2 = 0.41, p ≤ 0.01]) significantly increased with the gpp, but the anpp:gpp, apr:gpp and tbcf:gpp ratios were not significantly correlated to the gpp (p > 0.41). the tbcf:gpp ratio significantly increased with the soil c:n ratio (r2 = 0.93, p ≤ 0.01), with a concomitant decrease in the apr:gpp ratio (r2 = -0.88, p < 0.001) without a significant effect on the anpp:gpp ratio (p > 0.32). none of these fractions were correlated to the soil total or extractable phosphorus (p > 0.32). although periodic and intensive measurements were required to determine the whole carbon budget in the ten plots, by necessity, the number of sites was limited, and, therefore, our results would require further confirmation using whole carbon budgets from a wider range of soil and environmental conditions.
CCD CBERS and ASTER data in dasometric characterization of Pinus radiata D. Don (North-western Spain)
Sevillano-Marco, Eva;Fernández-Manso, Alfonso;Quintano, Carmen;Poulain, Marcela;
CERNE , 2013, DOI: 10.1590/S0104-77602013000100013
Abstract: a chinese-brazilian earth resources satellite (cbers) and an advanced spaceborne thermal emission and reflection radiometer (aster) scenes coupled with ancillary georeferenced data and field survey were employed to examine the potential of the remote sensing data in stand basal area, volume and aboveground biomass assessment over large areas of pinus radiata d. don plantations in northwestern spain. statistical analysis proved that the near infrared band and the shade fraction image showed significant correlation coefficients with all stand variables considered. predictive models were accordingly selected and utilized to undertake the spatial distribution of stand variables in radiata stands delimited by the national forestry map. the study reinforces the potentiality of remote sensing techniques in a cost-effective assessment of forest systems.
Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand
Rigueiro-Rodríguez, Antonio;Mouhbi, Rabia;Santiago-Freijanes, José Javier;González-Hernández, María del Pilar;Mosquera-Losada, María Rosa;
Scientia Agricola , 2012, DOI: 10.1590/S0103-90162012000100006
Abstract: horse grazing systems may affect productivity and biodiversity of understory developed under pinus radiata d. don silvopastoral systems, while acting as a tool to reduce the risk of fire. this study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of ulex europaeus l. and alpha (species richness, shannon-wiener) and beta (jaccard and magurran) biodiversity for a period of four years in a p. radiata silvopastoral system. the experiment consisted of a randomized block design of two treatments (continuous and rotational grazing). biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. the rotational grazing system caused damage to the u. europaeus shrub, limiting its recovery once grazing was stopped. however, the more intensive grazing of u. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce u. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.
Role of Heat Shock and Salicylic Acid in Antioxidant Homeostasis in Mungbean (Vigna radiata L.) Plant Subjected to Heat Stress
Amal A.H. Saleh,Dina Z. Abdel-Kader,Amr M. El Elish
American Journal of Plant Physiology , 2007,
Abstract: The objective of the present study was to examine the role of heat shock and salicylic acid in antioxidant homeostasis in mungbean (Vigna radiata L.) plant. Fifteen-day mungbean seedlings were divided into 6 groups. The first one kept in open air then harvested after 25 and 32 day post germination (negative control).The second one were exposed to 50°C for 3 h (heat stress) and then harvested after 10 days (positive control). The 3rd and 4th groups were exposed to 2 different heat shock temperature (40 and 45°C) for 1, 1.5 and 2 h. The fifth and sixth groups were sprayed with two different Salicylic Acid (SA) concentrations (0.5 or 1 mM). The groups from third to sixth were exposed to heat stress (50°C) for 3 h either directly or after week. The seedlings were harvested 10 days post heat stress. The results showed that, high temperature stress induced lipid peroxidation, electrolyte leakage and increased hydrogen peroxidase level. High temperature stress decreased catalase, peroxidase, ascorbic peroxidase activities and glutathione content. It was also found that high temperature stress induced a significant increase in endogenous SA concentration and superoxide dismutase activity. These deteriorative symptoms in the mung bean seedlings were ameliorated by heat shock treatments or SA application by decreasing lipid peroxidation and increasing catalase, peroxidase, ascorbic peroxidase, superoxide dismutase activities and glutathione content. Based on these results, it was presumed that the stress protection caused by heat shock treatments or SA application contributes to some extent to the enhanced activity of the free-radical scavenging systems.
Flight Dynamics and Abundance of Ips sexdentatus (Coleoptera: Curculionidae: Scolytinae) in Different Sawmills from Northern Spain: Differences between Local Pinus radiata (Pinales: Pinaceae) and Southern France Incoming P. pinaster Timber  [PDF]
Sergio López,Arturo Goldarazena
Psyche , 2012, DOI: 10.1155/2012/145930
Abstract: In January 2009, the windstorm “Klaus” struck the southern part of France, affecting 37.9 million m3 of maritime pine Pinus pinaster Aiton (Pinales: Pinaceae). This breeding plant material favored the outbreak of Ips sexdentatus (B?rner) (Coleoptera: Curculionidae: Scolytinae). As much of this timber is imported to the Basque Country (northern Spain), a potential risk to conifer stands is generated, due to the emergence of the incoming beetles. Thus, flight dynamics and beetle abundance were compared in different sawmills, according to the timber species (either local P. radiata D. Don or imported P. pinaster). A maximum flight peak of I. sexdentatus was observed in mid-June in P. pinaster importing sawmills, whereas a second lighter peak occurred in September. In contrast, only a maximum peak in mid-June was observed in P. radiata inhabiting beetles, being significantly smaller than in local P. pinaster trading sawmills. In addition, significant differences were found between imported P. pinaster and P. radiata regarding the number of insects beneath the bark. The development of IPM strategies for controlling I. sexdentatus populations is recommended, due to the insect abundance found in P. pinaster imported timber. 1. Introduction Bark beetles (Coleoptera: Curculionidae: Scolytinae) are an insect group that contains at least 6,000 species from 181 genera around the world [1]. Bark beetles are considered as important agents of forest succession and initiate the sequence of nutrient cycling in infested tree material [2]. However, it is well known that some species are among the most destructive insects of coniferous forests, representing a continuous threat [1, 3]. Although bark beetles tend to colonize dead or weakened trees, it is well reported that some species can attack healthy trees under epidemic conditions. Frequently, improper forestry management or adverse abiotic and climatic conditions (e.g., storms, fires, and droughts) act as precursors by providing breeding substrate that unleashes population outbreaks for these bark beetles species [4–6]. For instance, the storms “Vivian/Wiebke” in February/March 1990 and “Lothar” in December 1999 triggered the propagation of Ips typographus (L.) in Centre Europe [7]. Recently, “Klaus” named windstorm affected 37.9?million?m3 of maritime pine Pinus pinaster Aiton (Pinales: Pinaceae) in Aquitaine (southern France) during January 2009 [8]. As a consequence a great amount of windthrown timber was left as suitable breeding material for the six-toothed beetle I. sexdentatus (B?rner) Figure 1. Despite its
Identification of proanthocyanidins extracted from Pinus radiata D. Don bark
Cortés,Soledad; Pulgar,Hugo; Sanhueza,Verónica; Aspé,Estrella; Fernández,Katherina;
Ciencia e investigación agraria , 2010, DOI: 10.4067/S0718-16202010000200002
Abstract: the bark of pinus radiata d. don is recognized as a rich natural source of proanthocyanidins (pas). barks of pinus radiata d. don were extracted to produce a raw extract, and then purified to produce 4 fractions, with the aim of correlating its structural characteristics with the extract antioxidant capacity. the structural characterization was performed by acid catalysis in presence of phloroglucinol, foliowed by the detection of the components by high precision liquid chromatography (hplc). the subunits identified in the bark of pinus radiata were: epicatechin- (4?-2) - phloroglucinol (ec-p), catechin- (4á-2) - phloroglucinol (c-f) and (+) -catechin (c). the purified fractions showed different mean degree of polymerization (mdp), average molecular weight (amw), concentration and reaction yield (r) with phloroglucinol. the concentration of total phenols decreased according to the order in which the fractions were eluted. all the fractions presented a high antiradical activity (evaluated as scavenging capacity of radical dpph>). nevertheless, the fraction fu presented the greatest tannin concentration and antioxidant activity. the structural characteristics of the extract of pinus radiata d. don bark could be correlated with the antioxidant activity of the extract.
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