<?xml version="1.0" encoding="UTF-8"?><xml><records><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%">Jacobs, K A</style></author><author><style face="normal" font="default" size="100%">Berry, A M</style></author><author><style face="normal" font="default" size="100%">MacDonald, J D</style></author><author><style face="normal" font="default" size="100%">Costello, L R</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Pillsbury, N H</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Rooting responses of three oak species to low oxygen stress</style></title><secondary-title><style face="normal" font="default" size="100%">PROCEEDINGS OF A SYMPOSIUM ON OAK WOODLANDS: ECOLOGY, MANAGEMENT, AND URBAN INTERFACE ISSUES</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><publisher><style face="normal" font="default" size="100%">US DEPT AGR, FOREST SERV PACIFIC SW FOREST &amp; RANGE EXPTL STN</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 245, BERKELEY, CA 94701 USA</style></pub-location><pages><style face="normal" font="default" size="100%">91-99</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rooting characteristics were compared in blue (Q. douglasii), valley (Q. lobata), and cork oak (Q. suber) seedlings under hypoxic (low oxygen) conditions. A 50 percent reduction in root growth occurred in all species at an oxygen level of 4 percent, or an oxygen diffusion rate of 0.3 mu g cm(-2)min(-1). Blue oak formed few lateral roots regardless of oxygen level, but valley and cork oak root production decreased under hypoxic conditions. Four percent soil oxygen might be viewed as a minimum requirement for sustaining root growth of oaks in the field, and differences in root branching morphology may be correlated with tolerance of root hypoxia.</style></abstract></record></records></xml>