Factors Affecting Revegetation Success in Lakeshore Restorations

Project Staff: 

Principal Investigator: Susan Galatowitsch, Department of Horticultural Science, University of Minnesota

Additional Staff: Dana Vanderbosch, Research Assistant, Water Resources Science, University of Minnesota

Funding: 

USGS-WRRI 104B/ CAIWQ Competitive Grants Program

Project Duration: 

March 2006 - February 2008

Summary: 

Revegetating aquatic zones is crucial to the overall success of lakeshore restoration since improving fish habitat and reducing wave impacts depends on the development of emergent plant beds. Currently, there is little understanding of why aquatic plantings fail while a few succeed. Information based on experimental findings, rather than anecdotal observations) is needed on the importance of the effects of planting time, water depth, and kind of transplant used. Although aquatic plantings often include several species. Scirpus validus (soft-stem bulrush) is likely the most commonly used species in the northern freshwater lakes because of its tolerance to a wide range of environmental conditions. This study is a within-lake experiment of bulrush transplant survival and establishment. Within 5 lakes in the Minneapolis- St. Paul metropolitan area, a split-split plot experimental planting will be conducted in 2006. A 30 m length of lakeshore within each lake will be divided into two depth zones, 0-35 cm, 36-70 cm. Within each zone, transplanting of two types of propagules (large containers and mats) will be installed at monthly intervals. Data on the number and conditions of shoots will be collected prior to planting, 30 days after planting (initial success), and after winter (in summer 2007). We expect to identify combinations of factors that can increase the chances of transplant survival and post-planting expansion. Without such basic information, the recent widespread efforts to restore lakeshores will likely result in minimal change and interest may not be sustained.