<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>32</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Crowe, Angela Marie</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The role of silica depletion in the eutrophication of Lac La Biche, Alberta</style></title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://search.proquest.com/docview/304957466</style></url></web-urls></urls><pub-location><style face="normal" font="default" size="100%">University of Alberta</style></pub-location><volume><style face="normal" font="default" size="100%">Biological Sciences</style></volume><pages><style face="normal" font="default" size="100%">75</style></pages><language><style face="normal" font="default" size="100%">en</style></language><abstract><style face="normal" font="default" size="100%">Eutrophication of aquatic systems can induce silica (Si) depletion through enhanced production and sedimentation of diatoms. This may shift the phytoplankton assemblage to include increasing proportions of non-siliceous taxa such as potentially nuisance Cyanobacteria. I examined the role of Si depletion in the eutrophication of Lac la Biche, a large lake in northern Alberta. Paleolimnological analyses indicate that while Lac la Biche has undergone eutrophication since the mid-20 th century, there is no evidence for either Si depletion or Si mediated shifts in the relative proportion of diatoms and Cyanobacteria. However, I show through nutrient amendment experiments that Si depletion can be induced seasonally under specific nutrient regimes. Further, Si amendment significantly increased the proportion of diatoms relative to Cyanobacteria. I conclude that with ongoing eutrophication and anticipated declines in Si loading to aquatic systems associated with drought and climate warming, Si depletion may become increasingly important in structuring phytoplankton communities.</style></abstract><issue><style face="normal" font="default" size="100%">M. Sc.</style></issue><custom1><style face="normal" font="default" size="100%">Biology</style></custom1><custom2><style face="normal" font="default" size="100%">Lac La Biche</style></custom2><custom3><style face="normal" font="default" size="100%">http://www.worldcat.org/oclc/144529312</style></custom3><custom4><style face="normal" font="default" size="100%">Science</style></custom4></record></records></xml>