PERFORMANCE AND PHENOLOGY OF ALPINE HERBS ALONG A SNOW-MELTING GRADIENT

Responses of plants to the length of the growing season were studied in an alpine snow-bed by setting five plots along a snow-melting gradient. Performance and phenology were compared between the plots for five herbaceous species (Peucedanum multivittatum, Primula cuneifolia, Veronica stelleri var. longistyla, Solidago virga-aurea var. leiocarpa and Potentilla matsumurae). Performance characteristics measured were flower height, leaf height, leaf number, flower number and fruit number. In the late exposed plots with short snow-free periods, fruit-set was reduced in many species due to the decrease in flower number and/or the short growing season for fruit development. Veronica stelleri var. longistyla and Solidago virga-aurea var. leiocarpa, which decreased in flower and leaf numbers due to the short snow-free period, were sensitive to the short growing season. Peucedanum multivittatum was vigorous in the late exposed plots, but its slow flowering and fruiting prevented the fruit-set from developing in the last exposed plot. Primula cumeifolia and Potentilla matsumurae, quick flowering species that maintained their flower number throughout the snow-melting gradient, were considered the most successful species in late exposed habitats.