Species Variation in Root Tolerance of Soil Compaction and Poor Drainage

Abstract

Loam-over-compacted-clay and loam soil profiles were created in 10 cm × 10 cm × 25 cm containers. Containers were placed in trays of water to simulate poor subsoil drainage in the landscape. Four urban tolerant species, Acer negundo, Catalpa speciosa, Gleditsia triacanthos, Ulmus americana, and two less tolerant species, Quercus rubra and Acer saccharum, were direct seeded in the containers. Soil volumetric water content and oxygen diffusion rate were monitored. At the conclusion of the study, length of fine roots (< 2 mm diameter) was measured throughout the soil profile. Oxygen decreased and moisture increased with soil depth. Fine root density of all species decreased with depth except Ulmus Americana. Catalpa speciose was the only species showing a difference in root growth between soil types throughout the profile and had up to seven times the root density of other species at the surface and up to four times at the bottom. Root growth of most species seemed to be reduced more by high soil moisture and reduced aeration than soil texture and compaction.