EFFECT OF FORAGE SEEDING ON EARLY GROWTH AND SURVIVAL OF LODGEPOLE PINE

Smooth bromegrass (Bromus inermis Leys.), orchardgrass (Dactylis glome rata L.), alsike clover (Trifolium hybridum L.), and a mixture by mass of 40% orchardgrass, 40% alsike clover, and 20% white clover (Trifoli um repens L.), were sown at 0.5, 1.5, 3.0, 6.0, and 12.0 kg/ha on a fo rest clear-cut in the southern interior of British Columbia. The seedi ng treatments were monitored for 3 growing seasons following planting to determine their influence on the growth, survival and damage of pla nted one-year old lodge-pole pine (Pinus contorta var. latifolia Engel m.) seedlings. Competing vegetation reduced lodgepole pine diameter by up to 38% (P<0.004) and heights by up to 30% (P<0.005). Lodgepole pin e basal diameters (P<0.002), height (P<0.02) and survival (P<0.03) dec reased linearly with increasing forage seeding rate. Lodgepole pines p lanted with smooth bromegrass had up to 59% larger (P<0.01) diameters and were up to 33% taller (P<0.06) than those planted with orchardgras s at equal seeding rates by mass. Lodgepole pine cumulative mortality was 2 to 5 times greater (P<0.0001) on plots sown to alsike clover com pared to plots sown with smooth bromegrass or orchardgrass. Rodent dam age peaked between the first and second growing seasons at 24% of the lodgepole pine seedlings; rodent damage was similar (P>0.05) among the treatments and controls, and conifer survival, was independent (P>0.0 5) of rodent damage.