<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pinho, P</style></author><author><style face="normal" font="default" size="100%">Augusto, S</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author><author><style face="normal" font="default" size="100%">Pereira, M J</style></author><author><style face="normal" font="default" size="100%">Soares, A</style></author><author><style face="normal" font="default" size="100%">Máguas, C</style></author><author><style face="normal" font="default" size="100%">Branquinho, C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Causes of change in nitrophytic and oligotrophic lichen species in a Mediterranean climate: impact of land cover and atmospheric pollutants.</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental pollution (Barking, Essex : 1987)</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biodiversity</style></keyword><keyword><style  face="normal" font="default" size="100%">Distance of influence</style></keyword><keyword><style  face="normal" font="default" size="100%">Functional groups</style></keyword><keyword><style  face="normal" font="default" size="100%">land use</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen tolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">Pollutant sources</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">154</style></volume><pages><style face="normal" font="default" size="100%">380-389</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">With the aim of determining the main drivers of changes in nitrophytic and oligotrophic macro-lichen communities in an industrial region with a Mediterranean climate, we considered both land-cover types and atmospheric pollutants. We determined the relation between the abundance of nitrophytic and oligotrophic species with environmental factors considering the distance of influence of land-cover types. The results showed that oligotrophic species decreased in the proximity of artificial areas, barren land and agricultural areas, associated with higher concentrations of NO2 and Zn, and Ti, probably dust of industrial and agricultural origin. Nitrophytic species were positively related to all the mentioned land-cover types, and with higher concentrations of Fe and N. Magnesium, probably from ocean aerosols, was negatively related to oligotrophic species and positively to nitrophytic.</style></abstract><accession-num><style face="normal" font="default" size="100%">18222577</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, Anabela</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">In vitro cold storage of cork oak shoot cultures</style></title><secondary-title><style face="normal" font="default" size="100%">Plant cell, tissue and organ culture</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">in vitro conservation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">shoot proliferation</style></keyword><keyword><style  face="normal" font="default" size="100%">woody species</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><volume><style face="normal" font="default" size="100%">59</style></volume><pages><style face="normal" font="default" size="100%">155-157</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A simple system for in vitro conservation of cork oak shoot cultures (Quercus suber L.) is described. Cultures were stored in vitro on multiplication medium at 51 C without an intervening subculture for two years. The viability, multiplication rate and shoot elongation were evaluated after storage under dark and light conditions. Culture viability was negatively affected by light. In contrast, 50% of cultures survived after two years of cold storage in the dark. Multiplication rate of dark-stored cultures was similar to the controls, and shoot elongation was signiﬁcantly higher. Although the assessment of multiplication rate/shoot elongation is done at the end of the ﬁrst multiplication cycle, we observed that at least in some species such as Quercus suber, it is advisable to study the responsiveness of cultures during the ﬁrst three multiplication cycles following storage. The rooting capacity of shoots produced from dark-stored cultures was similar to non-stored controls. Cultures stored for 6, 12 or 24 months without subculture have similar responsiveness as the ones subcultured monthly. The storage of cultures at 5 C in the dark appears to be a promising technique for medium-term conservation of cork oak germplasm.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nutrient dynamics in crown tissues of cork-oak (Quercus suber L?.)</style></title><secondary-title><style face="normal" font="default" size="100%">Trees-Structure and …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Evergreen oaks</style></keyword><keyword><style  face="normal" font="default" size="100%">macronutrients</style></keyword><keyword><style  face="normal" font="default" size="100%">montado</style></keyword><keyword><style  face="normal" font="default" size="100%">seasonal patterns</style></keyword><keyword><style  face="normal" font="default" size="100%">tissue nutrient contents</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">247-254</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal fluctuation of N, P, K, Ca and Mg in leaves, young stems and fruits of young and mature Quercus suber trees growing at the same site was studied. Nutrient dynamics within the tree appeared to be linked to phenological events. Leaves maximized their nutrient con- tents throughout summer whereas stems maintained rather constant values during most of the year. Before the spring growth flush they apparently acted as temporary reservoirs for some nutrients, translocated from leaves or other organs, so that such nutrients would be easily invested in the new tissues. A significant investment was made in sink organs like flowers and fruits. The tree probably relies not only on leaves but also on other nutrient reservoirs like older branches and roots for an adequate supply to those sinks and to the spring growth. The importance of the sampling dates and the basis of expression used for nutrient concen- trations has also been emphasized. Nutrient contents and seasonal trends of the studied trees were similar to those of other evergreen oaks, although somewhat higher values for N, K, and Mg were found. Moreover, soil nutrient contents in the studied &quot;montado&quot; were much lower than in other Iberic oak stands. However the nutrient status and require- ments of cork-oak suggest high (or at least adequate) nutrient availability to the trees. The mechanisms by which this could be achieved are discussed.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nutrient dynamics in crown tissues of cork-oak (Quercus suber L?.)</style></title><secondary-title><style face="normal" font="default" size="100%">Trees-Structure and …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Evergreen oaks</style></keyword><keyword><style  face="normal" font="default" size="100%">macronutrients</style></keyword><keyword><style  face="normal" font="default" size="100%">montado</style></keyword><keyword><style  face="normal" font="default" size="100%">seasonal patterns</style></keyword><keyword><style  face="normal" font="default" size="100%">tissue nutrient contents</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1996///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/q29gp8tjeymuh2kx.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">247 - 254</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal fluctuation of N, P, K, Ca and Mg in leaves, young stems and fruits of young and mature Quercus suber trees growing at the same site was studied. Nutrient dynamics within the tree appeared to be linked to phenological events. Leaves maximized their nutrient con- tents throughout summer whereas stems maintained rather constant values during most of the year. Before the spring growth flush they apparently acted as temporary reservoirs for some nutrients, translocated from leaves or other organs, so that such nutrients would be easily invested in the new tissues. A significant investment was made in sink organs like flowers and fruits. The tree probably relies not only on leaves but also on other nutrient reservoirs like older branches and roots for an adequate supply to those sinks and to the spring growth. The importance of the sampling dates and the basis of expression used for nutrient concen- trations has also been emphasized. Nutrient contents and seasonal trends of the studied trees were similar to those of other evergreen oaks, although somewhat higher values for N, K, and Mg were found. Moreover, soil nutrient contents in the studied &quot;montado&quot; were much lower than in other Iberic oak stands. However the nutrient status and require- ments of cork-oak suggest high (or at least adequate) nutrient availability to the trees. The mechanisms by which this could be achieved are discussed.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, A</style></author><author><style face="normal" font="default" size="100%">Noronha, C</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Role of carbohydrates in micropropagation of cork oak</style></title><secondary-title><style face="normal" font="default" size="100%">Plant cell, tissue and organ …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon source</style></keyword><keyword><style  face="normal" font="default" size="100%">micropropagation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">reducing sugars</style></keyword><keyword><style  face="normal" font="default" size="100%">rooting</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year></dates><volume><style face="normal" font="default" size="100%">40</style></volume><pages><style face="normal" font="default" size="100%">159-167</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The influences of carbon sources, fructose, glucose, sorbitol and sucrose on shoot proliferation and in vitro rooting of cork oak (Quercus suber L.) were compared at a wide range of concentrations (1-6%, w/v). The highest number of shoots occurred on glucose-containing medium. Nevertheless, we have chosen 3% sucrose which induced a similar rate of proliferation but favoured shoot elongation, permitting an effectively higher number of shoots during transfers. Sorbitol and autoclaved fructose did not stimulate shoot proliferation. Adventitious root formation was strongly dependent on carbohydrate supply. Sorbitol and autoclaved fructose were completely ineffectively on rooting induction. Glucose was the most effective carbon source on rooting promotion followed by sucrose and filter-sterilized fructose. The rooting response induced by fructose was dependent on the sterilizing procedure. The number of adventitious roots produced per shoot increased with increasing glucose and sucrose concentration. The content of reducing sugars in leaves of proliferation cultures and in leaves and roots of rooted plantlets was more dependent on carbon concentration than on glucose or sucrose supplement. The results presented here show that carbohydrate requirements during cork oak micropropagation depend upon the phase of culture. Sucrose (3%) and glucose (4%) were the best carbon sources respectively during proliferation and rooting phases.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, A</style></author><author><style face="normal" font="default" size="100%">Noronha, C</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of in vitro cold storage on surviving and proliferation of cork-oak (Quercus suber L.) cultures</style></title><secondary-title><style face="normal" font="default" size="100%">Congreso Forestal Español, 14 e 18 Junho de 1993, Lourizán</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cold storage</style></keyword><keyword><style  face="normal" font="default" size="100%">cork-oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Germplasm</style></keyword><keyword><style  face="normal" font="default" size="100%">Medium-term storage</style></keyword><keyword><style  face="normal" font="default" size="100%">micropropagation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cork-oak cultures were stored in vitro without na intervening subculture, at 5º C in the dark for 5 months without loosing their capacity to regenerate when subcultured under standard conditions. The viability, proliferation rate and elongation of the explants were evaluated during 5 months of storage. Proliferation rate of stored cultures was observed during 5 months of storage. Proliferation rate of stored cultures was observed during the following 3 profileration cycles and compared to unstored controls of the same age. Shoot cultures survived with 100% viability and the proliferation rate was not statistically different from the controls. The results here described indicate the feasibility of establishing na in vitro active gene bank for Quercus suber.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Correia, O A</style></author><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author><author><style face="normal" font="default" size="100%">Catarino, F M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of bark-stripping on the water relations of Quercus suber L</style></title><secondary-title><style face="normal" font="default" size="100%">Scientia gerundensis</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">bark-stripping</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">Transpiration</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1992///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">195 - 204</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Quercus suber is the primary source of industrial cork and can produce cork every 9-10 years. The main objective of this work was to investigate the influence of bark stripping on the stomatal activity and water relations of cork-oak. For this purpose, diurnal changes on transpiration, stomatal conductance and water potencial were measured before and after bark stripping during July and August 1989 and 1990. The stripping on the trees had been done at various intensities. The water loss by the stripped surface was also measured. These results show that severe bark-stripping may lead to a decrease in stomatal conductance and considerable water losses. The stripping stress is not clearly dependent on the stripping coefficients, but rather on the water lost by the trunk which varies from tree to tree probably according to the phloemic tissues composition.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, A</style></author><author><style face="normal" font="default" size="100%">Noronha, C</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Influence of Growth Regulators on Shoot Proliferation in Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Auxins</style></keyword><keyword><style  face="normal" font="default" size="100%">browning</style></keyword><keyword><style  face="normal" font="default" size="100%">cork-oak</style></keyword><keyword><style  face="normal" font="default" size="100%">cytokinins</style></keyword><keyword><style  face="normal" font="default" size="100%">Forestry</style></keyword><keyword><style  face="normal" font="default" size="100%">multiplication</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">re-invigoration</style></keyword><keyword><style  face="normal" font="default" size="100%">re-multiplication</style></keyword><keyword><style  face="normal" font="default" size="100%">two-phase medium</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><volume><style face="normal" font="default" size="100%">70</style></volume><pages><style face="normal" font="default" size="100%">531-536</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Procedures have been developed to standardize the multiplication stage during mature cork-oak (Quercus suber L.) micropropagation. Axillary and terminal buds were established on Gresshoff and Doy basal medium containing 1 mg I−1 of 6-benzylaminopurine (BAP). Initiation of cultures was possible all over the year. The effects of BAP, Z, IBA, 1AA and NAA and various nutrient formulae on shoot growth and proliferation was investigated. BAP was more suitable than zeatin. Shoot proliferation and elongation were strongly improved by the combination BAP/IAA in the presence of low salt media, like Gresshoff and Doy or Woody Plant medium. Both rates were significantly increased when a double-phase culture system was used. Shoots have been multiplied for 1 year at the rate of three to four-fold every 4 weeks without any decline of vigour. Rooting was achieved by briefly dipping the basal ends of in vitro regenerated shoots in an IBA concentrated solution. The results here reported constitute a promising step towards large scale in vitro propagation of a species in which conventional vegetative propagation by cuttings is very difficult.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, A</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Micropropagation of mature cork-oak (Querqus suber L.): establishment problems</style></title><secondary-title><style face="normal" font="default" size="100%">Scientia gerundensis</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">browning</style></keyword><keyword><style  face="normal" font="default" size="100%">contaminants</style></keyword><keyword><style  face="normal" font="default" size="100%">cork-oak</style></keyword><keyword><style  face="normal" font="default" size="100%">micropropagation</style></keyword><keyword><style  face="normal" font="default" size="100%">phenolic compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">tissue culture</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">17-27</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Procedures have been developed to standardize the establishment stage during mature cork-oak (Quercus suber L.) micropropagation. Axillary and terminal buds cultured in Gresshof and Doy (1972) (GD) medium were used as first explant. Establishment of cultures was very difficult due to browning of the tissue and/or the medium and bacterial contamination. Browning problems, probably due to phenolic compounds exudation of the primary explant, were found to be higher in winter. Nevertheless, initiation of cultures was possible all over the year, presumably due to the preconditioning of cuttings. Explants were established in a GD medium containing 6-benzlaminopurine (BAP) 1 mgl-1. Every 4 weeks the cultures were subcultured to the same GD medium and induced to proliferate being 4:1 the multiplication rate. Shoots were induced to elongate by decreasing BAP concentration. In vitro rooting on agar-solidified medium suplemented with 1 mgl-1 indolacetic acid (IAA) gave the best results. Liquid medium (sorbarod system) and in vivo rooting were also assayed.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Romano, A</style></author><author><style face="normal" font="default" size="100%">Noronha, C</style></author><author><style face="normal" font="default" size="100%">Caçorino, A I</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Técnicas de propagação aplicadas ao melhoramento do sobreiro</style></title><secondary-title><style face="normal" font="default" size="100%">2.º Encontro sobre montados de sobro e azinho, realizado 4 e 5 de Junho de 1992 em Évora</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biologia</style></keyword><keyword><style  face="normal" font="default" size="100%">Conferências</style></keyword><keyword><style  face="normal" font="default" size="100%">Crescimento vegetal</style></keyword><keyword><style  face="normal" font="default" size="100%">Micropropagação</style></keyword><keyword><style  face="normal" font="default" size="100%">Sobreiro (Quercus Suber L.)</style></keyword><keyword><style  face="normal" font="default" size="100%">vegetal (citation)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><pages><style face="normal" font="default" size="100%">169-202</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Neste trabalho apresentam-se os resultados referentes a técnicas de propagação aplicadas ao sobreiro, nomeadamente estacaria e micropropagação. Nas condições ensaiadas a estacaria deu resultados negativos. Aparentemente o enraizamento de estacas só é possível em matéria juvenil, o que inviabiliza a utilização desta técnica no melhoramento do sobreiro. Pelo contrário, a micropropagação pode desempenhar papel relevante. No presente trabalho foram desenvolvidas metodologias que permitem propagar explantados provenientes de material adulto seleccionado. Com esta técnica, partindo de 100 explantados podemos, potencialmente, colocar 1400 plantas no campo, ao fim de 6 meses.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Correia, O A</style></author><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author><author><style face="normal" font="default" size="100%">Catarino, F M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Aspectos fisiológicos do descortiçamento em Querqus suber</style></title><secondary-title><style face="normal" font="default" size="100%">I Congresso Ibérico de Ciências Hortícolas, 18 a 21 de Junho de 1990 em Lisboa</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Descortiçamento</style></keyword><keyword><style  face="normal" font="default" size="100%">Fisiologia vegetal</style></keyword><keyword><style  face="normal" font="default" size="100%">Sobreiro (Quercus Suber L.)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year></dates><pages><style face="normal" font="default" size="100%">469-475</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Quercus suber is the primary source of industrial cork, and can produce cork every 9-10 years. The main objective of the present work was to investigate the influence of the bark stripping of the cork-oak on the stomacal activity and water relations. For this purpose, diurnal variations on transpiration, stomacal conductance and water potencial were studied before and after bark stripping during July and August 1989. The stripping on the trees had been done at various levels. The water loss by the stripping surface was also measured. These preliminary results show that the stress caused by stripping on these trees is different according to the stripping area. The transpiration is immediatly reduced after stripping, under the conditions of these investigations and high stripping coeficients. Sendo o sobreiro uma espécie que proporciona sucessivas tiradas de cortiça, um dos aspectos que importa salientar é o dos exagerados descortiçamentos, que poderão ser um factor de decréscimo de produtividade. Neste trabalho foi estudada a reacção de plantas submetidas a diferentes coeficientes de descortiçamento no que respeita aos parâmetros fisiológicos relacionados com o balanço hídrico e economia de água. Foram efectuados estudos ecofisiológicos em árvores descortiçadas nos meses de Julho 89/Agosto 89, tendo sido estudada a variação diurna da transpiração, condutância estomática e condutividade hidráulica. Foi igualmente determinada a perda de água, por evaporação, através do tronco até à formação de nova periderme. São apresentados resultados preliminares que põem em evidência o stress que o descortiçamento provoca nestas plantas e que é tanto mais grave quanto maior for o coeficiente de descortiçamento aplicado.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Correia, O A</style></author><author><style face="normal" font="default" size="100%">Oliveira, G</style></author><author><style face="normal" font="default" size="100%">Martins-Loução, M a</style></author><author><style face="normal" font="default" size="100%">Catarino, F M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Aspectos fisiológicos do descortiçamento em Querqus suber</style></title><secondary-title><style face="normal" font="default" size="100%">I Congresso Ibérico de Ciências Hortícolas, 18 a 21 de Junho de 1990 em Lisboa</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Descortiçamento</style></keyword><keyword><style  face="normal" font="default" size="100%">Fisiologia vegetal</style></keyword><keyword><style  face="normal" font="default" size="100%">Sobreiro (Quercus Suber L.)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1990</style></date></pub-dates></dates><pages><style face="normal" font="default" size="100%">469 - 475</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Quercus suber is the primary source of industrial cork, and can produce cork every 9-10 years. The main objective of the present work was to investigate the influence of the bark stripping of the cork-oak on the stomacal activity and water relations. For this purpose, diurnal variations on transpiration, stomacal conductance and water potencial were studied before and after bark stripping during July and August 1989. The stripping on the trees had been done at various levels. The water loss by the stripping surface was also measured. These preliminary results show that the stress caused by stripping on these trees is different according to the stripping area. The transpiration is immediatly reduced after stripping, under the conditions of these investigations and high stripping coeficients. Sendo o sobreiro uma espécie que proporciona sucessivas tiradas de cortiça, um dos aspectos que importa salientar é o dos exagerados descortiçamentos, que poderão ser um factor de decréscimo de produtividade. Neste trabalho foi estudada a reacção de plantas submetidas a diferentes coeficientes de descortiçamento no que respeita aos parâmetros fisiológicos relacionados com o balanço hídrico e economia de água. Foram efectuados estudos ecofisiológicos em árvores descortiçadas nos meses de Julho 89/Agosto 89, tendo sido estudada a variação diurna da transpiração, condutância estomática e condutividade hidráulica. Foi igualmente determinada a perda de água, por evaporação, através do tronco até à formação de nova periderme. São apresentados resultados preliminares que põem em evidência o stress que o descortiçamento provoca nestas plantas e que é tanto mais grave quanto maior for o coeficiente de descortiçamento aplicado.</style></abstract></record></records></xml>