Low-lying spots where the ground is saturated all year, or where there is standing water in the spring, are perfect conditions for hardwood swamps forests. The soil will usually be loamy, clayey or sandy. Hardwood swamp forests also develop on shallow peat, but hardwoods usually don't do well on deep "bouncy" peat.
The hardwood tree species best adapted to these conditions include: yellow birch (Betula alleghaniensis), and red maple (Acer rubrum). Under swamp conditions the trees will grow slowly, and probably never get as tall as they would on drier soil.
Several herbaceous plant species do well in a hardwood swamp forest, such as angelica (Angelica atropurpurea), red-stemmed aster (Symphyotrichum puniceum), and common marsh marigold (Caltha palustris).
These habitats are often important for erosion control and for "ground water recharge" where rainwater or runoff water is filtered as it seeps back into the groundwater.