In combination with geophysical methods the vegetation cover can give indications for the recent activity of rockglaciers, or help to reconstruct the temporal development where geomorphological indicators are absent.
For plants they represent an ulterior challenge for colonization and growth. Surface morphology and surface instability, both resulting of the movement of the rockglacier, have been found to exert important effects on vegetation patterns developing on it. Traditional studies addressing relationships between vegetation and surface instability in the alpine environment have been carried out on scree slopes and moraines. In both habitats, plant cover and patterns of surface movement are controlled primarily by slope angle and gravity. Relationships between vegetation patterns and surface instability in arctic and alpine regions have been the object of studies focusing on community typology, growing strategies and adaptations to mechanical disturbance, root mechanical properties, and vegetation dynamics.
Along with the type of rock that composes the rockglacier, the average diameter of debris and the movement velocities influence the type of plant succession and cover that can establish.
Missing fine material, and so missing colonisation niches for plant seedlings, seems to favourite plants that can grow between boulders, like Geum-species or shrubs. Active rockglaciers shows a colonisation by lichens, except for the front where pioneer species like Cerastium, Oxyria and the clubb moss Huperzia can be found.
Cerastium uniflorum (Caryophyllaceae)
Oxyria digyna (Polygonaceae)
Huperzia selago (Lycopodiaceae)
The species poor lichen assemblage develops in the middle of rockglacier,in direction of the rooting zone the lichen cover diminishes, to lack completely in the rooting zone. Lichens can be also used for dating the rockglacier by lichenometry.
A high movement causes a coarse-textured substrate; finer material fell off or between the greater, moving boulders. The resulting mechanical stress prevents the establishment of epilithic lichens on boulders.
CANNONE, N. & GERDOL, R. (2003): Vegetation as an Indicator of Surface Instability in Rock Glaciers. Arctic, Antarctic and Alpine Research. Vol. 35(3): 384-390
BURGA, C.A.; FRAUENFELDER, R.; RUFFET, J.; HOELZLE, M. & KÄÄB, A. (2004): Vegetation on Alpine rock glacier surfaces: a contribution to abundance and dynamics on extreme plant habitats. FLORA 199: 505-515