Stands of Maple - Ash Swamp Forest are located in backswamps, which are low areas set back from rivers that are often covered in standing water. When floods are sufficiently high, waters rise above riverbanks and spread far back into low-lying areas on the outskirts of the floodplain. The water is typically brown because it’s full of tiny particles of silt and clay. The silt and clay gradually settle out of the water onto the floor of the swamp, creating soil that’s fertile though very poorly drained. The regular influx of alluvial sediments has more influence on the fertility and texture of the soil than the underlying bedrock.

The forest floor in the Maple - Ash Swamp tends to have a hummock-and-hollow shape (small mounds and depressions). That’s because it’s hard for trees to stay upright in continuously wet soil. When they fall, their roots pull up soil and rocks, creating a mound and leaving behind a hole. During a flood or after a rain, water is deeper in the hollows and takes longer to drain away. Lizard’s-tail thrives in the standing water, whereas new silver maple and/or red maple and green ash trees take root on the slightly higher mounds.