Figure 4. Dry matter density of vertical canopy layers within temperate perennial grasses (KBG, Kentucky bluegrass; PRG, perennial ryegrass; OGR, orchardgrass; TIM, timothy; TFK, Kentucky 31-type tall fescue; TFS, soft-leaf tall fescue; MDF, meadow fescue; SBG, smooth bromegrass; RCG, reed canarygrass; QGR, quackgrass) in the summer of 2 yr. Error bars indicate one standard error.