SIMULATION OF CROWN FIRE EFFECTS ON CANOPY SEED BANK IN LODGEPOLE PINE

Analysis of video footage taken of crown fires during the 1988 fire se ason in Yellowstone National Park indicated that the most frequent len gth of time required to completely burn tree crowns was 15-20 seconds. Lodge-pole pine (Pinus contorta Laws.) seeds were tested for ability to germinate after exposing both serotinous and nonserotinous cones fo r 10 to 60 seconds in a flame front designed to simulate a crown fire. Heating enhanced germination of seeds from serotinous cones but not t hose from nonserotinous cones. Maximum germination rates for serotinou s cone seeds ranged from 37 to 64 percent and occurred after 10-20 sec onds exposure of cones to flames. Germination after 60 seconds exposur e averaged 0.3 to 14 percent. Maximum germination of seeds from nonser otinous cones (about 80%) occurred with no exposure and after 10 secon ds in the flames.