Vegetation influences near-surface hydrological characteristics on a surface coal mine in eastern USA

Mining processes alter natural landscapes worldwide, and methods for restoration of mined areas are widely studied. Establishment of vegetation is essential to mined land restoration. Prior research has addressed vegetative influence on erosion and runoff, but effects of vegetation type on surface hydrologic processes are less studied. We measured infiltration rates and observed subsurface flow paths in mine soils on a reforested area and a grassed area on a former surface coal mine in the eastern United States. The two areas were constructed and reclaimed fourteen years prior to our study using processes similar in all aspects except vegetation. MiniDisk tension infiltrometers and Brilliant Blue FCF dye staining analyses were utilized to evaluate near-surface flow processes in the vegetated mine soils. Mean infiltration rates were 16.5±10.7cmh−1 and 10.4±7.7cmh−1 for the reforested and grassed areas, respectively. Infiltration rates, hydraulic conductivities, dye coverage, and dye stained areas were significantly higher in the reforested area. The grassed area had constant dye coverage with depth but more flow paths than the reforested area. A transition from vegetation-controlled subsurface flow to abiotic-control at greater depths was evident in the stained soil profiles. Results highlight the heterogeneous nature of mine soils and the influence of vegetation type in development of mine soil hydrologic processes. •Infiltration and dye staining patterns on a surface coal mine were examined.•Significantly higher infiltration occurs in reforested areas than in grassed areas.•Dye coverage decreases with depth in forest; grassed coverage is constant.•The grassed area has significantly more flow paths than the reforested area.