GERMINATION ECOLOGY OF SOME COMMON FOREST HERBS IN YELLOWSTONE-NATIONAL-PARK, WYOMING, USA

Seed viability and dormancy mechanisms were investigated in seven herb aceous plant species and one low shrub species common in the first few years of postfire succession in subalpine forests of Yellowstone Nati onal Park, Wyoming, U.S.A. Seeds of Epilobium angustifolium (fireweed) had rapid and high percent germination in both the fall and spring af ter seeds were collected. Seeds of Lupinus argenteus (lupine) germinat ed well after several months of warm or cold storage, and the rate of germination but not the final percent germination was increased by sca rification. Seeds of Arnica cordifolia (heartleaf arnica) were nearly all non-viable; only one seed germinated out of 650 tested, and no see dlings were observed in the field. Small sample sizes limited the scop e of testing of the other species, but both Cirsium arvense (Canada th istle) and Epilobium ciliatum (willow-herb) showed moderate to high ge rmination in the spring after several months of storage, Hieracium alb iflorum (hawkweed) germinated better in the fall than in the following spring, Vaccinium scoparium (dwarf huckleberry) seeds germinated in t he fall 1 mo after collection, and seeds of Antennaria racemosa (pussy -toes) failed to germinate when tested in the fall 1 mo after collecti on. These results, combined with field studies, indicate that large-sc ale fires provide opportunities for recruitment of new genetic individ uals, increased genetic diversity, and colonization of new patches on the forest floor in several species, including Epilobium angustifolium , Lupinus argenteus, Hieracium albiflorum, and Cirsium arvense. These effects are likely to persist for many decades in these long-lived per ennial plant species.