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Carbon allocation dynamics one decade after afforestation with Pinus radiata D. Don and Betula alba L. under two stand densities in NW Spain

Fernández-Núñez, E.; Rigueiro-Rodríguez, A.; Mosquera-Losada, M.R.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.06%
Silvopastoral systems can contribute to the mitigation of climate change by functioning as sinks for greenhouse gases better than exclusively agricultural systems. Tree species, density, and an adequate management of the pasture carrying capacity contribute to the capacity of carbon sequestration. In this study, the capacities for carbon sequestration in silvopastoral systems that were established with two different forest species (Pinus radiata D. Don and Betula alba L.) and at two distinct densities (833 and 2500 trees ha−1) were evaluated. Tree, litterfall, pasture and soil carbon storage determinations were carried out to deliver carbon sequestration in the different pools within the first 11 years of a plantation establishment. The results show that the global capacity for carbon sequestration in silvopastoral systems with pine canopy was higher than with birch cover. Independently of the forest species, the capacity for carbon sequestration increased when the systems were established at higher plantation densities. There were found strong differences in the relative proportions of carbon in each component of the system (litterfall, tree, pasture and soil). The soil component was found to be most important in the case of the broadleaf forest established at low density. The establishment of a silvopastoral system enhanced soil carbon storage...

Afforestation of agricultural land with Pinus radiata D. don and Betula alba L. in NW Spain: effects on soil PH, understorey production and floristic diversity eleven years after establishment

Rigueiro-Rodríguez, A.; Mosquera-Losada, M.R.; Fernández-Núñez, E.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.54%
Afforestation of abandoned agricultural lands has been the main change in land use over the past decade in Europe. However, the impact of tree species and understorey management on production and plant diversity over the medium- and long-term has not been thoroughly studied. This paper aims to evaluate the effects of an afforestation of Pinus radiata D. Don and Betula alba L. on soil pH, understorey production and plant diversity and life cycle type (annuals vs. perennials) managed with different soil fertilisation treatments over a period of 11 years. The results show an acidification of the soil 11 years after establishment, better vertical growth and diameter of pine compared with birch as usually happens in the region and important variation in the biomass production and composition of the understorey below both tree species. Understorey species remained similar during the first 5 years below both canopies. However, species richness (S) was drastically reduced under Pinus radiata D. Don plantation compared to Betula alba L. (Spine = 2 vs. Sbirch = 17) after 11 years of tree establishment at a very high density (2500 trees ha−1). Inorganic and organic fertilisation also caused a reduction in floristic diversity. Soil pH...

Avaliação da madeira de Betula pendula, Eucalyptus globulus e de híbrido de Eucalyptus grandis x Eucalyptus urophylla destinadas à produção de polpa celulósica Kraft; Evaluation of the wood of Betula pendula, Eucalyptus globulus and of hybrid of Eucalyptus grandis x Eucalyptus urophylla as a raw-material for kraft pulp production

Duarte, Francismara Aparecida Sanches
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/06/2007 PT
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37.66%
A madeira é a principal variável de custo na produção de polpa celulósica. A polpa celulósica obtida a partir da madeira de folhosas é principalmente utilizada para produção de papéis de escrita e impressão assim como, a produção de papéis para fins sanitários; para estes usos normalmente a polpa celulósica deve ser branqueada. Mundialmente, várias espécies de madeira de folhosas são utilizadas para produção de polpa celulósica de fibra curta, estando entre as principais o híbrido Eucalyptus grandis x Eucalyptus urophylla (Brasil), Betula pendula (Finlândia) Eucalyptus globulus (Portugal). Este projeto teve por objetivo: i-avaliar e comparar o desempenho de madeiras de principais espécies utilizadas mundialmente, para produção de polpa celulósica de fibra curta, considerando os aspectos relacionados à qualidade da madeira e polpa, o consumo de reagentes químicos na polpação e também os aspectos relacionados ao rendimento e a capacidade de produção de polpa celulósica; ii-fornecer informações estratégicas para o setor celulósico nacional com relação as possíveis ameaças e as oportunidades apresentadas pelos materiais não utilizados no Brasil, visando o conhecimento e posicionamento em competitividade destas madeiras no mercado mundial de celulose e papel; iii-fornecer subsídios para o programa genético e de melhoramento florestal; iv-posicionar a polpa celulósica de Eucalyptus grandis x Eucalyptus urophylla em relação as suas principais concorrentes. Para realização deste trabalho foram coletadas 5 árvores de todas as espécies...

Upgrading of suberin from cork and birch outer bark; Valorização da suberina da cortiça e da casca externa da bétula

Sousa, Paula Andreia Fernandes de
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
27.82%
O trabalho aqui apresentado teve como principal propósito o estudo do potencial da suberina como fonte de produtos de química fina e como precursor de novos materiais macromoleculares de origem renovável. O interesse na suberina reside, não só na sua ubiquidade e nas suas propriedades únicas em termos de composição química e hidrofobicidade, mas também no facto de ser um dos principais componentes macromoleculares dos subprodutos da indústria corticeira de Quercus suber L. no Sul da Europa, e da indústria de pasta de papel do Norte da Europa, que utiliza a Betula pendula Roth como matéria-prima. A primeira parte do presente trabalho consistiu no estudo detalhado da composição química da cortiça de Quercus suber L. e respectivos resíduos industriais bem como da casca de Betula pendula Roth recorrendo a diferentes técnicas de caracterização, nomeadamente GC-MS, IV, RMN de 1H e de 13C, DSC, termomicroscopia, TGA e difracção de raios-X. Os resultados mostraram que os produtos de despolimerização da suberina representam tipicamente uma fracção substancial de todas as amostras. Para além da suberina, foram também identificados nas diversas amostras quantidades variáveis de compostos triterpénicos, lenhina, polissacarídeos e matéria inorgânica. Os principais resultados da análise por GC-MS mostraram que todas as amostras de suberina despolimerizada são fontes abundantes de ω-hidroxiácidos e de ácidos dicarboxílicos...

Quercus suber and Betula pendula outer barks as renewable sources of oleochemicals: A comparative study

Pinto, Paula C. R. O.; Sousa, Andreia F.; Silvestre, Armando J. D.; Neto, Carlos Pascoal; Gandini, Alessandro; Eckerman, Christer; Holmbom, Bjarne
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.36%
A comparative study on the chemical composition of oak cork (Quercus suber L.) and corresponding industrial residues and birch (Betula pendula L.) outer bark is reported. Cork oak samples have lower extractives contents (6-9%) and higher contents of carbohydrates and lignin (23-27 and 33-38%, respectively) than those found for birch outer bark (40, 6 and 9%, respectively); suberin contents accounted for around 30% of cork, 11% of industrial cork powder and 45% of birch outer bark. Analysis of the suberin monomeric composition revealed that C18 and C22 omega-hydroxyfatty acids (including mid-chain epoxy- and dihydroxy-derivatives), followed by alpha,omega-dicarboxylic acids, are the main components in both suberins, with 9,10-epoxy-18-hydroxyoctadecanoic, 18-hydroxyoctadec-9-enoic, 9,10,18-trihydroxyoctadecanoic and octadec-9-enoic acids as the major components. The differences in the relative amounts of these acids in the suberin samples and the impact on the potential exploitation of the different industrial by-products are discussed. (C) 2008 Elsevier B.V All rights reserved.; WaCheUp project - STRP 013896; EC/6FP - priority 3, NMP

The European project HIALINE (Health Impacts of Airborne Allergen Information Network): results of pollen and allergen of Betula monitoring in Parma (2009)

R. Albertini; Ugolotti M.; Buters J.; Weber, B.; Thibaudon, M.; Smith, M.; Galán C.; U. Berger; Brandao, R. M.; Antunes, C.M.; Grewling L.; A. Rantio-Lehtimäki; Cecchi, Lorenzo; I. Sauliene; Sofiev, M.
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
27.36%
Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content in ambient air is unknown. HIALINE therefore monitored atmospheric concentrations of Betula, Poaceae and Olea pollen grains and matched their major allergens Bet v1, Phl p5 and Ole e1 across Europe. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. New knowledge through the use of new experimental approaches in the field of aerobiological monitoring will enable better in the prevention and clinical management of pollinosis. In order to disseminate the knowledge of the project we present the results of first year of birch pollen grains and the matched major pollen allergen Bet v1 monitored in Parma (UNIPR), Italy with a short reference to the results obtained by the other participants and about developing models of dissemination and forecasts of pollen and allergens. Materials and methods. The pollen was sampled by a Hirst pollen trap. Allergens was collected with a CHEMVOL® high-volume cascade impactor...

Estudo químico de extratos de folhas de Betula celtiberica Rothm. & Vasc.

Serra, Ana Patrícia Abrantes
Fonte: Universidade da Beira Interior Publicador: Universidade da Beira Interior
Tipo: Dissertação de Mestrado
Publicado em /06/2013 POR
Relevância na Pesquisa
37.75%
O período de estágio final, inserido no Plano de Estudos do Mestrado em Ciências Farmacêuticas da Universidade da Beira Interior, permitiu desenvolver competências técnicas, clínicas e deontológicas necessárias ao exercício da profissão farmacêutica. O presente trabalho encontra-se dividido em duas componentes, sendo a primeira o projeto de investigação de mestrado intitulado “Estudo Químico de Extratos de folhas de Betula celtiberica Rothm. & Vasc.” e a segunda o Relatório de Estágio em Farmácia Comunitária. No que concerne ao projeto de investigação de mestrado, o estudo químico de extratos de Betula celtiberica, obtidos por diferentes métodos de extração, baseou-se fundamentalmente na determinação da sua atividade antioxidante, na quantificação de fenóis totais e flavonoides, com recurso a métodos colorimétricos. Posteriormente os extratos foram submetidos a análise por HPLC-DAD para identificação de compostos presentes na planta. Com os resultados obtidos concluiu-se que o vidoeiro possui elevada capacidade antioxidante pois alguns extratos, mais precisamente o extrato obtido por polaridade crescente com o solvente metanol, apresentam AAI > 2. Pela análise dos cromatogramas obtidos por HPLC-DAD identificaram-se dois compostos...

Artificial neural network model of the relationship between Betula pollen and meteorological factors in Szczecin (Poland)

Puc, Małgorzata
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.36%
Birch pollen is one of the main causes of allergy during spring and early summer in northern and central Europe. The aim of this study was to create a forecast model that can accurately predict daily average concentrations of Betula sp. pollen grains in the atmosphere of Szczecin, Poland. In order to achieve this, a novel data analysis technique—artificial neural networks (ANN)—was used. Sampling was carried out using a volumetric spore trap of the Hirst design in Szczecin during 2003–2009. Spearman’s rank correlation analysis revealed that humidity had a strong negative correlation with Betula pollen concentrations. Significant positive correlations were observed for maximum temperature, average temperature, minimum temperature and precipitation. The ANN resulted in multilayer perceptrons 366 8: 2928-7-1:1, time series prediction was of quite high accuracy (SD Ratio between 0.3 and 0.5, R > 0.85). Direct comparison of the observed and calculated values confirmed good performance of the model and its ability to recreate most of the variation.

Four Novel Cellulose Synthase (CESA) Genes from Birch (Betula platyphylla Suk.) Involved in Primary and Secondary Cell Wall Biosynthesis

Liu, Xuemei; Wang, Qiuyu; Chen, Pengfei; Song, Funan; Guan, Minxiao; Jin, Lihua; Wang, Yucheng; Yang, Chuanping
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 25/09/2012 EN
Relevância na Pesquisa
27.54%
Cellulose synthase (CESA), which is an essential catalyst for the generation of plant cell wall biomass, is mainly encoded by the CesA gene family that contains ten or more members. In this study; four full-length cDNAs encoding CESA were isolated from Betula platyphylla Suk., which is an important timber species, using RT-PCR combined with the RACE method and were named as BplCesA3, −4, −7 and −8. These deduced CESAs contained the same typical domains and regions as their Arabidopsis homologs. The cDNA lengths differed among these four genes, as did the locations of the various protein domains inferred from the deduced amino acid sequences, which shared amino acid sequence identities ranging from only 63.8% to 70.5%. Real-time RT-PCR showed that all four BplCesAs were expressed at different levels in diverse tissues. Results indicated that BplCESA8 might be involved in secondary cell wall biosynthesis and floral development. BplCESA3 appeared in a unique expression pattern and was possibly involved in primary cell wall biosynthesis and seed development; it might also be related to the homogalacturonan synthesis. BplCESA7 and BplCESA4 may be related to the formation of a cellulose synthase complex and participate mainly in secondary cell wall biosynthesis. The extremely low expression abundance of the four BplCESAs in mature pollen suggested very little involvement of them in mature pollen formation in Betula. The distinct expression pattern of the four BplCesAs suggested they might participate in developments of various tissues and that they are possibly controlled by distinct mechanisms in Betula.

Temporal and spatiotemporal autocorrelation of daily concentrations of Alnus, Betula, and Corylus pollen in Poland

Nowosad, J.; Stach, A.; Kasprzyk, I.; Grewling, Ł.; Latałowa, M.; Puc, M.; Myszkowska, D.; Weryszko- Chmielewska, E.; Piotrowska-Weryszko, K.; Chłopek, K.; Majkowska-Wojciechowska, B.; Uruska, A.
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.36%
The aim of the study was to determine the characteristics of temporal and space–time autocorrelation of pollen counts of Alnus, Betula, and Corylus in the air of eight cities in Poland. Daily average pollen concentrations were monitored over 8 years (2001–2005 and 2009–2011) using Hirst-designed volumetric spore traps. The spatial and temporal coherence of data was investigated using the autocorrelation and cross-correlation functions. The calculation and mathematical modelling of 61 correlograms were performed for up to 25 days back. The study revealed an association between temporal variations in Alnus, Betula, and Corylus pollen counts in Poland and three main groups of factors such as: (1) air mass exchange after the passage of a single weather front (30–40 % of pollen count variation); (2) long-lasting factors (50–60 %); and (3) random factors, including diurnal variations and measurements errors (10 %). These results can help to improve the quality of forecasting models.

Estructura y dinámica de una población de "Betula Alba" L. en las llanuras sedimentarias de la Cuenca del Duero (tramo medio del Río Cega - Cuéllar - Segovia-)

Guerra Velasco, Juan Carlos; García de Celis, Alipio José; Arroyo Pérez, Pablo
Fonte: Universidad de Alcalá. Servicio de Publicaciones Publicador: Universidad de Alcalá. Servicio de Publicaciones
Tipo: Artigo de Revista Científica Formato: 6731237 bytes; application/pdf
SPA
Relevância na Pesquisa
27.36%
En La Tierra de Pinares segoviana, dentro de las llanuras sedimentarias de la Cuenca del Duero, pervive una notable población de abedul (Betula alba L.). Situada en el tramo medio del río Cega, en las proximidades de la localidad de Cuéllar, aprovecha las condiciones topoecológicas y las manifestaciones hidromorfológicas que introduce el pequeño encajonamiento del río.; In the plains of the Tierra de Pinares (Segovia Province, Spain) remains a population of birch (Betula alba L.). These are the only birch trees on the plains of the Duero basin. There are a few groups of trees located on the banks of the Cega river, in a particular hidromorphological and topoecological position: the very tilt and unstable slopes of the little Cega canyon, and its walls from which groundwater flows out constantly.

Fractioning and chemical characterization of barks of Betula pendula and Eucalyptus globulus

Miranda, Isabel; Gominho, Jorge; Mirra, Inês; Pereira, Helena
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
37.36%
The composition of birch (Betula pendula Roth.) and eucalypt (Eucalyptus globulus Labill.) barks was studied after grinding and fractioning into different particles sizes. There was a significant difference in the fractionation of both barks in relation to the yield of fines (5.9% and 28.3% of particles under 0.450 for birch and eucalypt, respectively) and of coarser particles over 2 mm (70.7% and 41.4%). The chemical composition of birch and eucalypt barks, as a mass weighed average of all granulometric fractions was, respectively: ash 2.9% and 12.1%; total extractives 17.6% and 6.5% (hydrophilic extractives were dominant), lignin 27.9% and 28.8% and holocellulose 49.8% and 62.6%. Birch bark contained a considerable amount of suberin (5.9%) whereas eucalypt bark contained a very small amount (<1%). The carbohydrate composition differed between birch and eucalypt barks, i.e., respectively, glucose 47.0% and 68.4%, and xylose 33.8% and 23.2% of total neutral monosaccharides. Ash elemental composition was different in both species. Birch bark contained in relation to eucalypt bark, in the 0.250–0.450 mm fraction, more N (0.69% vs. 0.26%) and P (0.075% vs. 0.001%), and less Ca (0.39% vs. 0.62%), K (0.24% vs. 0.31%) and Mg (0.07% vs. 0.15%). High concentration of Zn was found in birch bark (217 mg/kg vs. 11 mg/kg in eucalypt bark). After grinding and granulometric separation...

Parâmetros hídricos em angiospermas lenhosas de clima temperado durante os estádios de repouso e crescimento; Water parameters in temperate zone woody angiosperms during the rest and growth stages

SIMÕES, Fabiano
Fonte: Universidade Federal de Pelotas; Biologia; Programa de Pós-Graduação em Fisiologia Vegetal; UFPel; BR Publicador: Universidade Federal de Pelotas; Biologia; Programa de Pós-Graduação em Fisiologia Vegetal; UFPel; BR
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
27.54%
The knowledge of physiological processes during both dormancy and vegetative growth is important for adaptation processes in temperate zone woody angiosperms, especially in water management by those plants. The objectives of this work were to evaluate the water content and carbohydrate metabolism during the progress of dormancy in pears, to evaluate strategies of water use in two woody species (apple and walnut), which were subjected to three different levels of water deficit, and also to evaluate reliability of air injection technique to induce cavitation in three woody angiosperms. The first experiment was conducted during autumn and winter of 2008 in Brazil, and it was used plants of pears cultivars Packham's Triumph and Housui. The second study was carried out during the summer season of 2009 in France, with apple and walnut trees under water stress. The third experiment was done in France in 2009, and three species of woody angiosperms with different lengths of xylem were used Betula pendula, Prunus persica and Quercus robur. From the results it was concluded that the water content in tissues might be a marker of dormancy progression for cv. Packham's Triumph. However, the data were not conclusive and clear in cv. Housui. Stomatal closure might be an important parameter for preventing xilemian cavitation in walnut and apple trees subjected to soil water deficit. Apple trees stomata grown under severe drought regime remained partially open...

Influência das diferentes granulometrias na composição química das cascas de Eucalyptus globulus Labill., Betula pendula Roth, Picea abies (L.) Karst, Pinus sylvestris L. e Pinus pinea L.; Influence of different particle sizes in the bark chemical composition of Eucalyptus globulus Labill., Betula pendula Roth, Picea abies (L.) Karst, Pinus sylvestris L. e Pinus pinea L.

Mirra, Inês Martins Pereira
Fonte: ISA/UTL Publicador: ISA/UTL
Tipo: Dissertação de Mestrado
Publicado em //2011 POR
Relevância na Pesquisa
27.36%
Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia; The goal of this report is to characterize the bark of five industrially important forest species in Europe - Eucalyptus globulus, Betula pendula, Picea abies, Pinus sylvestris e Pinus pinea and to define their potential use as a source of value added chemical products. It was performed the anatomical characterization of bark tissues (dissociated elements), the selective fractionation (size distribution, characterization of particle shape, separation of density and determination of bulk density), the average of basic chemical composition and particle size of three reference fractions (ash, extractives, suberin, Klason lignin, acid soluble lignin, holocellulose and 1% NaOH extraction). The anatomical study shows that there is no differential separation of the cellular elements of the tissues of the bark in seven particle size fractions. The physical process of fractioning showed that, for all barks, over 50% of the mass of material consisted of coarse particles with 6 mm average diameter. On the other hand, there was no direct correlation between the values of bulk density and particle diameter. It has only been possible to separate the birch bark and scots pine by difference in density fluctuations in water. The mean values of the chemical composition brought out that the barks of softwood showed higher content of total extractives...

Estudo químico de extratos de folhas de Betula celtiberica Rothm. & Vasc.

Serra, Ana Patrícia Abrantes
Fonte: Universidade da Beira Interior Publicador: Universidade da Beira Interior
Tipo: Dissertação de Mestrado
Publicado em /06/2013 POR
Relevância na Pesquisa
37.75%
O período de estágio final, inserido no Plano de Estudos do Mestrado em Ciências Farmacêuticas da Universidade da Beira Interior, permitiu desenvolver competências técnicas, clínicas e deontológicas necessárias ao exercício da profissão farmacêutica. O presente trabalho encontra-se dividido em duas componentes, sendo a primeira o projeto de investigação de mestrado intitulado “Estudo Químico de Extratos de folhas de Betula celtiberica Rothm. & Vasc.” e a segunda o Relatório de Estágio em Farmácia Comunitária. No que concerne ao projeto de investigação de mestrado, o estudo químico de extratos de Betula celtiberica, obtidos por diferentes métodos de extração, baseou-se fundamentalmente na determinação da sua atividade antioxidante, na quantificação de fenóis totais e flavonoides, com recurso a métodos colorimétricos. Posteriormente os extratos foram submetidos a análise por HPLC-DAD para identificação de compostos presentes na planta. Com os resultados obtidos concluiu-se que o vidoeiro possui elevada capacidade antioxidante pois alguns extratos, mais precisamente o extrato obtido por polaridade crescente com o solvente metanol, apresentam AAI > 2. Pela análise dos cromatogramas obtidos por HPLC-DAD identificaram-se dois compostos...

Silica-cast replicas for morphology studies on spruce and birch xylem

Persson, Per Valdemar; Fogden, Andrew; Hafren, Jonas; Daniel, Geoffrey; Iversen, Tommy
Fonte: National Herbarium and Botanic Gardens Publicador: National Herbarium and Botanic Gardens
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.36%
Sol-gel mineralization has been used and evaluated as a tool for morphological studies on Picea abies and Betula verrucosa. Wood specimens and a pulped spruce sample were impregnated with a silica sol-gel and subsequently heated (calcined) to condense the

Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century

Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz; Hansen, Birger U; Hansen, Marc O; Stecher, Ole; Elberling, Bo
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.75%
Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910–1930 to 1990–2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991–1996) and a positive effect on Betula nana radial growth...

Assessment of metal availability to vegetation (Betula pendula) in Pb-Zn ore concentrate residues with different features

Marguí, Eva; Queralt Mitjans, Ignacio; Carvalho, M.L.; Hidalgo, M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 323765 bytes; application/pdf
ENG
Relevância na Pesquisa
37.36%
In this work, characterisation of several ore concentrate remains from an abandoned Pb-Zn mining factory was performed determining chemical and physical properties such as pH, organic carbon content, particle size distribution, total heavy metal content (Pb, Zn, Cu, As and Cd) as well as mineralogical composition which showed, in most cases, the oxidization of the parent ore material (mostly galena: PbS and sphalerite: ZnS) to more mobile fractions as anglesite (PbSO4) and goslarite (ZnSO4). Moreover, two operational defined extraction procedures commonly used in soil and sediment studies (first and second steps of BCR procedure and DTPA extraction protocol) were applied in the different mining wastes in order to study Pb and Zn mobility and likely bioavailability to Betula pendula growing on the same mining spoils, which presents lead and zinc contents in leaves over ten times background values. Physicochemical characteristics and mineralogy of mining tailings determine metal availability to vegetation in abandoned mining sites.; This work has been done in the framework of the Transmin Project, founded by the Spanish National Research Programme (PPQ-2001-2100-C04) and within the CSIC-JNICT (Spain-Portugal) international co-operation agreement (2001PT0009). Finally...

Variation in stemflow volume and chemistry in black birch (Betula lenta L.) in relation to tree size and associated bark textural changes

Ryan, William
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Relevância na Pesquisa
27.36%
Levia, Jr., Delphis F.; Stemflow can be described as the transfer of precipitation by gravity along the stem of a plant to the surface of the ground during and as a result of precipitation events. It has been shown to be an important component of the hydrology and nutrient-cycling systems of forested areas. Although stemflow is a spatially- concentrated source of nutrients and water, its effects are wide-ranging. In addition to having local effects on flora, fauna, and soil characteristics, stemflow can move through the soil matrix through root channels and other chasms in the soil strata. This allows for rapid translocation of water and chemical compounds downslope to wetlands and streams, thereby affecting a greater area. This study focuses on the variation in stemflow volume and chemistry from Betula lenta L. in relation to tree size and associated bark textural changes. Betula lenta L., known commonly as black birch, is a deciduous canopy tree native to the Eastern United States. This species was chosen for the study because it exhibits a dramatic contrast in bark texture as a function of tree size and age. Twenty-four trees were selected for inclusion in the study, encompassing three size-classes. The size- classes, which are classified as small...

Um caso peculiar de anafilaxia a maçã e feijão-verde

Gomes,Raquel; Viana,Jorge; Carrapatoso,Isabel; Loureiro,Carlos; Borja,Bartolomé; Todo-Bom,Ana
Fonte: Sociedade Portuguesa de Alergologia e Imunologia Clínica Publicador: Sociedade Portuguesa de Alergologia e Imunologia Clínica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2015 PT
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Introdução: Na alergia alimentar é frequente a reatividade cruzada entre aeroalergénios e alergénios alimentares, tendo como exemplo a síndrome bétula -maçã. No entanto, a alergia a Rosaceas (maçã) por sensibilização a Bet v 1 é caracterizada mais frequentemente por manifestações clínicas ligeiras (síndrome de alergia oral), sendo um fenótipo típico do norte da Europa. Descrição do caso: Doente do sexo masculino, 54 anos, residente em Portugal, com antecedentes de rinite e três reações anafiláticas após ingestão de maçã e feijão -verde. Do estudo alergológico salientam-se testes cutâneos e/ou IgE específica positivos para pólen de Betula sp., maçã e feijão-verde associados a um perfil de sensibilização a Bet v 1 e Gly m 4. Discussão/Conclusão: A análise inicial, atendendo ao quadro clínico, sugere alergia a Rosaceas por sensibilização a LTP, que não se confirma, identificando -se antes sensibilização a Bet v 1 e cuja gravidade parece estar associada à cosensibilização a Gly m 4