Tuesday, August 3, 2010

PS 33-82: Effects of surface mining on soil properties in a wetland ecosystem

Kelly Conley, Robert Morris University, Sherri J. Morris, Bradley University, and William J. Dress, Robert Morris University.

Background/Question/Methods

Surface mining for coal is an ongoing environmental issue.  The disruptive nature of surface mining can affect the ambient soil properties that are in place before the mining occurs.  The Banner Marsh State Fish and Wildlife Area, southwest of Peoria on U.S. Route 24 in Fulton and Peoria counties, was surfaced mined from the 1960s through the 1980s.  The wetland ecosystem of Banner Marsh is of particular environmental interest due to wildlife habitat that it provides and also that one million gallons of water per day pass through an aquifer from Banner Marsh to the Illinois River.  Soil samples of depths of 0 to 10cm and 10 to 25cm were taken from non mined, mined, and reclaimed dump sites at Banner Marsh to determine nutrient and water holding properties of the soils.  Soil C, N and C:N ratios were determined for all sites.  Lab incubations were also set up to determine C and N mineralization rates. 

Results/Conclusions

Soil moisture did not differ across sites.  Total C and N and C mineralization rates did not differ between non mined and reclaimed mine sites.  At the 0-10 cm depth, total organic C, soil C:N ratio, and C mineralization rates were greater in soils that were reclaimed than those that were not reclaimed.  At 10-25 cm soil C mineralization rates were also greater on the reclaimed soils than the non reclaimed sites.  Our results to date suggest that organic matter does build up on reclaimed sites at rates similar to soils that were not mined.  However soils that remain without vegetation, either because they were not reclaimed or because the soil conditions are not conducive to vegetation, do not recover organic matter or microbial activities at the same rates.