<?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%">Nardini, Andrea</style></author><author><style face="normal" font="default" size="100%">Tyree T., Melvin</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root and shoot hydraulic conductance of seven Quercus species</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">high pressure flow meter</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf blade resistance</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Root hydraulic conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">shoot hydraulic conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><volume><style face="normal" font="default" size="100%">56</style></volume><pages><style face="normal" font="default" size="100%">371-377</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The root (KR) and shoot (KS) hydraulic conductances of seven different Quercus species, as well as the leaf blade hydraulic resistance (RLL), were measured in potted plants with the aim of understanding whether a relationship exists between the hydraulic architecture and the general ecological behaviour of different species of this genus. The KR values were scaled by dividing by root surface area (KRR) and by leaf surface area (KRL) and the KS values were scaled by dividing by leaf surface area (KSL). The likely drought-adapted species (Quercus suber, Q. pubescens, Q. petraea) showed lower KRL and KRR, lower KSL and higher RLL with respect to the known water-demanding species (Q. alba, Q. cerris, Q. robur, Q. rubra). The possible physiological and ecological significance of such differences 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%">Nardini, Andrea</style></author><author><style face="normal" font="default" size="100%">Ghirardelli, Lia</style></author><author><style face="normal" font="default" size="100%">Salleo, Sebastiano</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Vulnerability to freeze stress of seedlings of Quercus ilex L.: an ecological interpretation</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">freeze stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex L.</style></keyword><keyword><style  face="normal" font="default" size="100%">root and stem hydraulic conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">553-565</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The vulnerability to freeze stress of seedlings of Quercus ilex L. was studied with the aim of defining the limits of the potential distribution area of this species in its northernmost habitat. In December 1996 seedlings were freeze stressed up to -8 °C for 3 d. Frost caused extensive functional damage to seedlings in terms of: a) leaf water status; b) root (Kr) and stem (Ks) hydraulic conductance; c) tissue disorder in the root (only nine seedlings out of 50 survived). In comparison with unstressed seedlings, Kr and Ks of freeze-stressed seedlings were reduced by 90 %. Root anatomy of freeze-stressed seedlings revealed that: a) cortex cells were dehydrated and had become separated from one another; b) the endodermis was oversuberized, thus isolating the stele from the cortex. Our conclusion was that Q. ilex is extremely vulnerable to freeze stress so that the distribution area of the species is restricted to zones with no frost events</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%">Nardini, Andrea</style></author><author><style face="normal" font="default" size="100%">Gullo, Maria Assunta Lo</style></author><author><style face="normal" font="default" size="100%">Tracanelli, Stefano</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Water relations of six sclerophylls growing near Trieste (Northeastern Italy): has sclerophylly a univocal functional significance?</style></title><secondary-title><style face="normal" font="default" size="100%">Giornale botanico italiano</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">drought tolerance (PG)</style></keyword><keyword><style  face="normal" font="default" size="100%">sclerophylls</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">Taylor &amp; Francis</style></publisher><volume><style face="normal" font="default" size="100%">130</style></volume><pages><style face="normal" font="default" size="100%">811-828</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract The annual time course of the water relations of six sclerophylls has been studied with the aim of: a) defining strategies adopted for withstanding summer water stress and b) to check whether their common sclerophyllous habitus could represent a case of convergent evolution devoted to a univocal functional role. In particular, Phillyrea latifolia L. showed to behave like a drought tolerant as indicated by deep summer drop in leaf water potential (?1) to near the full turgor loss point (?lp) and in leaf relative water content (RWC) as caused by xylem cavitation. Prunus laurocerasus L. and Laurus nobilis L. showed to be drought avoiding water spenders in that their ?1 dropped in summer causing prompt recovery in RWC. This was made possible by low cavitation in their twigs. Ilex aquifolium L. was a typical drought avoiding water saver in that both ?1 and RWC remained at very high levels throughout the year. Quercus ilex L. behaved like a drought avoiding water spender which switched to drought tolerance in the warmest period of the year. This was explained by its high vulnerability to cavitation. The extreme heterogeneity of the six species studied suggested that sclerophylly cannot be interpreted as an anatomical feature leading to a specific and unifying functional role, at least as regards drought resistance.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1080/11263509609438352</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1080/11263509609438352</style></research-notes></record></records></xml>