The forest has developed on the thin and stony soils of the flat areas and small hills along the east bank of the river.

[2] The Laval River Rare Forest is a young stand of black spruce (Picea mariana) and red pine (Pinus resinosa).

The presence of red pine is unusual, since it is far from its normal range, which in Quebec is mainly the deciduous forest area to the west of the Gatineau River where the climate is milder and fires are more common.

Trunks are sometimes over 20 centimetres (7.9 in) in diameter at chest height and only 8 metres (26 ft) high, probably due to poor soil.

The fire seems to have been the cause of the low density of trees and the abundant Ericaceae and lichens in the undergrowth, which reduces competition from balsam fir.