01206naa a2200169 a 450000100080000000500110000800800410001910000180006024501140007826000090019252006750020165000280087665000190090465300260092370000180094977300690096712796842025-02-21       1983    bl uuuu     u00u1 u    #d1 aWARING, R. H.  aPhysiological stress in lodgepole pine as a precursor for mountain pine beetle attack.h[electronic resource]  c1983  aThe premise that mature lodgepole pine forests are susceptible to mountain pine beetle attack when physiologically stressed was evaluated by manipulating the canopy density and availability of nitrogen in a 120-year-old forest exposed to a high population of beetles. Where canopy density was reduced and nitrogen nutrition improved, trees significantly increased their resistance to attack. Changes in tree vigor were quantified by estimating increases in wood production per unit of leaf area. These changes were determined from cores and are therefore ractical for assessing mortality risk from beetle attacks and for developing protective strategies P or management.  aDendroctonus ponderosae  aPinus contorta  aEstresse fisiológico1 aPITMAN, G. B.  tZietshcrift fur Angewandte Entomologiegv. 96, p. 265-270, 1983.