Effect of burning on seed production of bluebunch wheatgrass, Idaho fescue, and Columbia needlegrass

Abstract

A study was conducted in 1984 to determine the effect of fall prescribed burning on seed production of bluebunch wheatgrass (Agropyron spicatum), Idaho fescue (Festuca idahoensis), and Columbia needlegrass (Stipa columbiana) in the sagebrush (Artemisia spp.)/grassland region. Plots were located on 7 burns of ages 1 to 5 years, with plots in adjacent unburned areas serving as controls. Seed production (seeds per plant) of bluebunch wheatgrass was greater on 2 of four 1-year-old burns and on one 3-year-old burn than on unburned comparison areas. Idaho fescue seed production was greater on a 5-year old burn than on the control plot, but not statistically different from the controls on 1- or 3-year-old burns. Columbia needlegrass seed production was markedly greater on a 2-year-old burn than on adjacent unburned areas. The percentage of filled florets and the number of seeds per inflorescence tended to be greater on burned plots for all 3 species. Bluebunch wheatgrass showed a variable response in the number of inflorescences produced per plant 1 year after burning, but there were significantly (P is lesser than or equal to 0.05) more inflorescences per plant on the 3-year-old burn than the control. Idaho fescue plants produced fewer inflorescences on both 1-year-old burns than on the control plots, but more on the 5-year-old burn than on the control. Columbia needlegrass plants produced more inflorescences on the burn than on the control.