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: <em>Dryadetum drummondi</em> (37%). <em>Juniperetum horizontalis</em> (15%). <em>Dryadetum integrifolae</em> (4%) and <em>Potentilletum fruticusae</em> (3%) as well as by 6 less Important communities. primarily herbaceous. Four new subassociations are presented: <em>D. d. dryadetosum drummondii. D. d. danthonietosum spicatae, D. i. juniperetosum horizontalis</em> and <em>J. h. dryadetosum integrifoliae</em>. 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.