Submitted to: Billings Reclamation Symposium
Publication Type: Proceedings
Publication Acceptance Date: 5/6/2006
Publication Date: 6/8/2006
Citation: Wick, A.F., Stahl, P.D., Ingram, L.J., Schuman, G.E., Vance, G.F. 2006. Aggregate size distribution and stability under a cool season grass community chronosequence on reclaimed coal mine lands in Wyoming. pp.806-815. In: Reclamation: Supporting future generations. Billings Reclamation Symposium. Interpretive Summary:
Technical Abstract: Mine reclamation success is currently based on aboveground ecosystem components, mainly vegetation characteristics, with little consideration of belowground components. Recovery of belowground components, such as soil structure, is also crucial to the successful reclamation of disturbed lands. Inadequate recovery of belowground ecosystem components during reclamation could affect ecosystem function and lead to future site degradation. In this study, above- and belowground components were sampled on reclaimed mine sites in Wyoming representing various ages (undisturbed, a 3 month old topsoil stockpile, 11, 24, and 28 year old reclamation) to determine if aboveground indicators of recovery accurately reflect recovery of soil structure and function. Cool-season grass (native and reclaimed) communities were sampled for aboveground biomass production, cover and diversity according to Wyoming Department of Environmental Quality standards. Soil samples were analyzed for aggregate size distribution and stability with wet sieving. There was a decreasing trend in aggregate size for all reclaimed sites, indicating the incorporation of silt and clay (<53 µm) and microaggregates (53-250 µm) into macroaggregates (250-2000µm). This is indicative of soil structural recovery through time. A significant relationship was evident between aboveground biomass production and macroaggregate formation (R2 = 0.46); however, no relationship was exhibited for microaggregate formation. There was no relationship among total cover, macro- and microaggregate formation. In conclusion, these data suggest that even though soil structure is showing recovery, aboveground ecosystem components of reclaimed mine lands do not fully reflect this recovery.