Soil-vegetation relationships on a cobbly limestone floodplain. Anticosti Island, Quebec

Abstract

The limestone floodplain of the Galiote River. Anticosti Island (Quebec) is occupied by 4 shrub associations: Dryadetum drummondi (37%). Juniperetum horizontalis (15%). Dryadetum integrifolae (4%) and Potentilletum fruticusae (3%) as well as by 6 less Important communities. primarily herbaceous. Four new subassociations are presented: D. d. dryadetosum drummondii. D. d. danthonietosum spicatae, D. i. juniperetosum horizontalis and J. h. dryadetosum integrifoliae. The vegetation colonizes soil representative of the Regosolic. Brunisolic and Gleysolic orders, composed of calcareous material at pH greater than 7 with a base saturation capacity of more than 100%. These soils are first colonized by pioneer plants such as Dryas. which stabilize the substrate thus facilitating the establishment of a less specialized vegetation and leading finally to forest development. This succession follows a topographical gradient that runs from the river to the forest; the river being the principle element determining the distribution of the described plant communities.