An assessment of structural attributes and ecosystem function in restored Virginia coalfield streams

As human populations continue to grow, expanding energy needs enhance freshwater resource conservation challenges. Mining for coal has significantly altered the landscape in the United States' Appalachian region, with significant negative effects on downstream water quality and ecosystem function. With recent policy changes concerning the impacts of coal mining on aquatic ecosystems, many coal companies choose to restore sections of stream located on older coal mining areas as mandated compensatory mitigation for mining-related stream disturbances. We assessed such mitigation using measures of both structure and function in restored and unrestored streams affected by surface mining operations. Macroinvertebrate assemblages in streams affected by older mining and recent restoration practices were rated as stressed and severely stressed, with streams varying from fair to optimal in terms of habitat. All streams were net heterotrophic with varying levels of ammonium uptake. No site differences were found for any measured physicochemical or functional variables, while invertebrate community metric scores were higher in unrestored streams. There were also no significant relationships found between structural and functional measurements in these streams. Principal components analysis implicated the importance of measuring physicochemical, structural, and functional variables in further analyses of restoration success. This study was unable to document pre-disturbance conditions, and as a result, we were unable to find evidence that restoration is currently having a significant effect on ecosystem processes within these systems. Further research is needed to understand the changes in ecosystem structure and function that come with time.