<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>32</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Drew, Allan P.</style></author></authors><tertiary-authors><author><style face="normal" font="default" size="100%">Fritts, H.</style></author></tertiary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Stomatal Activity in Semi-arid Site Pnderosa Pine</style></title><secondary-title><style face="normal" font="default" size="100%">Watershed Management</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1967</style></year></dates><publisher><style face="normal" font="default" size="100%">University of Arizona</style></publisher><volume><style face="normal" font="default" size="100%">MS</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A pressure-infiltration technique for estimating stomatal opening in conifers was used with success on ponderosa pine growing on a semi-arid site. A diurnal pattern of stomatal opening during the day and closing at night was readily discernible. Variations in this pattern such as changes in rates of opening, daytime closure, and opening at night have been measured and related to changes in the environment. Incoming radiation, air and soil temperature, and soil moisture strongly influenced stomatal activity.</style></abstract></record></records></xml>