Surface forms of organic soils in Southern Ontario and Quebec

Basin bog

A basin bog in Ontario formed in a closed, poorly drained depression where rainwater and snowmelt slowly accumulate, creating acidic, nutrient‑poor peat.

Basin swamp

A basin swamp formed in a low‑lying depression where slow‑moving, mineral‑rich groundwater and surface runoff collect, supporting water‑tolerant trees and dense shrub layers.

Horizontal fen

A horizontal fen formed where mineral‑rich groundwater flows evenly across a broad, gently sloping surface, creating a continuously saturated wetland carpeted by sedges, mosses, and low shrubs.

Stream marsh

A stream marsh formed along a slow‑flowing stream where frequent flooding creates shallow, sunlit wetlands dominated by cattails, sedges, rushes, and other emergent aquatic plants.

Stream swamp

A stream swamp in formed along a slow‑moving stream where frequent flooding keeps the soils saturated and rich in nutrients. Water‑tolerant trees grow alongside dense shrubs and wetland plants.