Range and wildland improvement projects conducted throughout the Intermountain region normally occur within specific plant communities. Each plant community has unique features that require different equipment, planting techniques, and plant materials to conduct improvement projects. Plant communities or associations discussed in this chapter are: (1) subalpine herblands and upper elevation aspen openings, (2) wet and semiwet meadows, (3) inland saltgrass, (4) riparian, (5) aspenconifer, (6) mountain brush-ponderosa pine, (7) juniper-pinyon, (8) sagebrush, (9) salt desert shrub, (10) blackbrush, (11) annual weedy grasses - cheatgrass brome, red brome, and medusahead, and (12) lowland annual weeds.