Community ecology of arboreal lianas in gallery forests of the Rhine valley, France
The phanerophyte liana population of Clematis vitalba and Hedera helix is described in different successional stands of the gallery forests of the Rhine valley, Alsace, France. The liana population presents a wide variety of abundance along the Rhine and its tributary, the Ill, according to gradients of light, flooding severity, hydromorphy or presence of shade tree species. In the Rhine forests, young (30 years) and old (150 years) stands were chosen of Salici-Populetum (including two sub-associations), Fraxino-Populetum albae and Ligustro-Populetum nigrae. Four stands were selected in end-successional Querco-Ulmetum: 2 in the sub-association populetosum (one prone to flooding, the other deprived of flooding since canalization in 1960), one in the sub-association carpinetosum (deprived of flooding since the building of dykes in 1850) and one in the sub-association tilietosum, on high, sandy terraces. In the Ill forests, the liana population was studied in 4 associations which segregate along a moisture gradient: Alnetum glutinosae, Pruno-Fraxinetum, Alno-Carpinetum and Stellario-Carpinetum.