<?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%">Gratani, L</style></author><author><style face="normal" font="default" size="100%">Bombelli, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Leaf anatomy, inclination, and gas exchange relationships in evergreen sclerophyllous and drought semideciduous shrub species</style></title><secondary-title><style face="normal" font="default" size="100%">PHOTOSYNTHETICA</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cistus incanus</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf inclination</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf life-span</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf mass/area ratio</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf thickness</style></keyword><keyword><style  face="normal" font="default" size="100%">net photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">transpiration rate</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><publisher><style face="normal" font="default" size="100%">INST EXPERIMENTAL BOTANY, ACAD SCI CZECH REPUBLIC</style></publisher><pub-location><style face="normal" font="default" size="100%">NA KARLOVCE 1A, PRAGUE 6 CS-160 00, CZECH REPUBLIC</style></pub-location><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">573-585</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">There are significant differences in leaf life-span among evergreen sclerophyllous species and drought semideciduous species growing in the Mediterranean maquis. Cistus incanus, which has a leaf life-span of four-eight months, was characterised by the highest net photosynthetic rates (PN). while Quercus ilex and Phillyrea latifolia, which maintain their leaves two-three and two-four years, respectively, had a lower PN- The longer leaf life-span of the two evergreen sclerophyllous species may be justified to cover the high production costs of leaf protective structures such as cuticle, hairs, and sclereids: cuticle and hairs screen radiation penetrating into the more sensitive tissues, and sclereids have a light-guiding function. Q. ilex and P. latifolia have the highest leaf mass/area ratio (LMA = 209 g m(-2)) and a mesophyll leaf density (2065 cells per mm(2) of leaf cross section area) about two times higher than C. incanus. In the typical evergreen sclerophyllous species the steepest leaf inclination (alpha = 56 degrees) reduces 42% of radiation absorption, resulting in a reduced physiological stress at leaf level, particularly in summer. C. incanus, because of its low leaf life-span, requires a lower leaf investment in leaf protective structures. It exhibits a drastic reduction of winter leaves just before summer drought, replacing them with smaller folded leaves. The lower leaf inclination (alpha = 44 degrees) and the lower LMA (119 g m(-2)) of C. incanus complement photosynthetic performance. Water use efficiency (WUE) showed the same trend in Q. ilex, P. latifolia, and C. incanus, decreasing 60% from spring to summer, due to the combined effects of decreased CO2 uptake and increased transpirational water loss.</style></abstract></record></records></xml>