<?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%">Méthy, M</style></author><author><style face="normal" font="default" size="100%">Trabaud, L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal courses of photosynthetic activity and sublethal temperature tolerance of Quercus ilex leaves</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic apparatus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex (PG)</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year></dates><volume><style face="normal" font="default" size="100%">61</style></volume><pages><style face="normal" font="default" size="100%">339-348</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The reaction of the photosynthetic system of a sclerophyllous tree of the Mediterranean region (Quercus ilex) to three temperature levels (one ambient and two sublethal) was analysed monthly for 1 year. Measurements were carried out on leaves less than 3 months old as well as on leaves older than 3 months by laser-induced chlorophyll fluorescence. Treatments were: control (unheated), 50°C for 30 min, and 60°C 10 min. Both for unheated and treated leaves the vitality index shows a seasonal course depending on the treatments. At 50°C the photosynthetic apparatus of leaves of the two ages is moderately affected. At 60°C the apparatus is severely damaged whatever the season and is unable to recover. The consequences for the management of Q. ilex forests in relation to some thermal stresses are considered.</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%">Trabaud, L</style></author><author><style face="normal" font="default" size="100%">Méthy, M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effets de températures sub-létales sur l'appareil photosynthétique du chêne vert (Quercus ilex L)</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%">fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1992</style></year></dates><volume><style face="normal" font="default" size="100%">49</style></volume><pages><style face="normal" font="default" size="100%">637-649</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Effects of sub-lethal temperatures on the photosynthetic apparatus of Quercus ilex L. Resistance to high temperatures by the photosynthetic system of leaves of a sclerophyllous tree growing in the Mediterranean basin (Quercus ilex) has been studied using the fluorescence induction technique. Registration of the kinetics with determination of fluorescence decrease ratio was carried out every month for 1 year. According to the dates of sampling, leaves were sorted into 2 categories: &gt; 3 months and &lt; 3 months. They were heated at temperatures of 50, 55 and 60 °C for periods ranging from 0 to 30 min. After sclerification was established (≈ 1 month old) leaves withstood heat with only limited damage at 50 °C. In contrast, the photosynthetic system was totally destroyed when exposed to 60 °C for 30 min. Leaves collected in July displayed some adaptation to high temperatures. The consequences on the functioning of Q ilex in an environment with high temperatures have been examined.</style></abstract></record></records></xml>