Comparisons of germination traits of alpine plants between fellfield and snowbed habitats

摘要

We examined the seed-germination responses of 27 alpine species with reference to habitat type (fell-field and snowbed), temperature (five regimes), and light requirement. About 70% of species showed > 40% germination at warm temperatures without cold stratification. However, a moist-chilling treatment markedly improved the germination percentages in most species, especially under cool conditions. Thus, cold stratification effectively reduced the temperature requirement for germination. Patterns of germination response within species were not consistent between the fellfield and snowbed habitats for species inhabiting both habitats. For interspecific comparisons, there were no significant differences in germination responses to the temperature regimes and the cold stratification between the fellfield and snowbed species. Also, germination speed and the length of germinating period did not differ between fellfield and snowbed species. Most species (86%) showed a requirement for light for germination without cold stratification. Although the extent of the light requirement was reduced after cold stratification in some species, the light requirement of most small-seeded species remained. The combination of cold stratification and the light requirement is a major factor determining the seedling emergence and formation of seed banks in alpine plants. However, habitat-specific patterns of germination traits were less clear, suggesting similar germination traits in fellfield and snowbed plants, at least under controlled conditions in the laboratory.