Thursday, August 6, 2009

PS 73-168: Evaluating dune restorations in the Great Lakes region

Sarah M. Emery, University of Louisville and Jennifer A. Rudgers, Rice University.

Background/Question/Methods

Because of the economic and environmental importance of stabilizing fragile sand dune habitats, restoration of dunes has become a common practice. Restoration efforts in the Great Lakes and East coast regions of North America often consist of planting monocultures of the dominant native grass species, Ammophila breviligulata. We evaluated 18 dune restoration projects in the Great Lakes region conducted over the past 25 years to assess whether these traditional planting efforts effectively restored biodiversity and ecological processes. We characterized attributes of diversity (plants and insects), vegetation structure (plant biomass and cover), and ecological processes (soil nutrients and mycorrhizal fungi abundance) in each restoration, and compared these measures to geographically paired natural dune communities.

Results/Conclusions

Restoration sites did not differ from reference sites in most measured variables. The differences between restorations and reference sites were mostly explained by differences in ages, with the younger sites supporting slightly lower plant diversity and mycorrhizal spore abundance than older sites. Plant community composition varied little between restored and reference sites, with only one native species, Artemisia campestris, occurring significantly more often in references than restored sites. In general, traditional restoration efforts in Great Lakes sand dunes appear to be achieving targets of diversity and ecological processes found in reference communities.