5 -
Habitat selection
Snowbed plants are restricted to places of guaranteed and long-lasting snow cover. They
represent the most sensitive group with respect to freezing tolerance. Snow protects these
plants from critically low temperatures
(Soldanella pusilla,
Central Alps 2500 m). What looks like extreme stress in fact represents one of the
places in the Alpine which is best protected from critically low temperatures. Snow fields in
snow accumulation habitats melt very late in spring. Snowbed specialists such as
Soldanella
species have preformed flowers (made in the previous season) which start to expand, once
"warm", zero degree melting water seeps into their rosettes and once solar radiation
penetrates the thinned snow pack. The fragile flowers do not push through snow and ice, they
"melt through". Their flowers attract long wave radiation which causes snow to melt
faster in the immediate neighbourhood of such structures. This assists these plants to make
efficient use of the short season at such snowbed habitats.