Effects of Snow-Free Period on the Phenology of Alpine Plants Inhabiting Snow Patches

Abstract

Phenology of alpine plants was studied with reference to the time span of snow-free period by setting six quadrats along a snowmelt gradient. Of the 56 species, 17 inhabited four or more quadrats and their phenology was observed for 3 yr, 1988 to 1990. Contraction of the snow-free period reduced flowering and seeding rates. Phenology of the alpine plants was controlled primarily by (1) growth form, (2) the span of preflowering, and (3) the term for the maturity of seeds. Shrub species, especially evergreen shrubs, took longer for maturing their seeds. They abandoned sexual reproduction and reproduced vegetatively by layering in the short snow-free habitats. Forb and graminoid species opened their flowers even in the