Effects of variations in stand structure on development of mixed-species stands in eastern Washington

The development of six mixed-species, even-aged stands was reconstructed in the eastern Washington Cascade Range. All stands were within the Grand Fir Climax Series and began following stand replacement disturbances. Western larch (Larixoccidentalis Nutt.) and lodgepole pine (Pinuscontorta Dougl. ex Loud.), when present, formed an upper stratum over interior Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) and grand fir (Abiesgrandis (Dougl.) Lindl.) in all six stands. Establishment patterns and species composition affected stand development patterns. Douglas-fir benefitted from the absence of lodgepole pine; grand fir benefitted from the absence of Douglas-fir, but apparently not from the absence of lodgepole pine. Lodgepole pine had faster initial diameter growth rates than western larch when it became established relatively early and in large numbers.