Pollen analyses were undertaken on a small peat bog (Ecuelles
06° 49′ 41″E, 45° 58′ 49″N, 1855m asl ), located on the Anterne
mountain (Upper-Arve Valley, French north-western Alps). The
study highlights the role of green alder (Alnus alnobetula
[Ehrh] K. Koch) in Holocene vegetation dynamics of the nowadays
treeless subalpine belt. At this place, the onset of human
perturbation caused a retreat of fir and arolla-pine stands and
an expansion of green alder, which consequently dominated the
landscape from 3700 up to 1965 cal. BP. After 1965 cal. BP, the
clearings led to the present grasslands with few ligneous
species (spruce, larch) on inaccessible cliffs or green alder on
the edges of torrents or in avalanche corridors. Picea
percentages have increased after 3900 cal. BP, but, due to human
activities, spruce has never constituted large stands in the
study area. The present general expansion of green alder is due
to the decreasing human impact and it constitutes the first step
of re-afforestation that should