Terrestrial Native Species and Habitat Restoration

Science Center Objects

During the first five years of the Great Lakes Restoration Initiative, federal agencies and their partners worked to maintain, restore and enhance populations of native species. The following actions were taken to improve conditions for the endangered and threatened species: bog turtle, Canada lynx, copperbelly water snake, Eastern Massasauga rattlesnake, Hines emerald dragonfly, Karner blue butterfly, Kirtland’s warbler, lakeside daisy, Mitchell’s satyr butterfly, piping plover, and Pitchers thistle. 

Conserving and Restoring Midwestern Oak Savannas

USGS is collaborating with NPS to test different combinations of management actions (native plant reintroductions, chemical and mechanical removal of invaders, soil microbial manipulations, and fire) to determine which are most effective at restoring the high diversity groundlayer representative of rare sand dune and oak savanna habitats. Results from this effort will help NPS and other agencies make better-informed management decisions in the future. 

Karner blue butterfly
(Public domain.)

Midwestern oak savannas are one of the most endangered ecosystems in the world. For over two decades there has been considerable interest in the status, conservation, and restoration of oak savannas. Many oak savannas are important habitat for plant and animal species of concern, including the endangered Karner Blue butterfly. Across the Great Lakes region, we are examining the efficacy of ongoing oak savanna restoration by examining constellation of sites from Ohio to Wisconsin. How well are land managers doing with groundlayer restoration? What methods are working to restore oak savannas? What processes and their interactions are contributing to oak savanna groundlayer diversity? We are examining the condition of the groundlayer diversity in relation to types of common treatments in the region, such as untreated, burned, thinning of overstory, and seeding. From this broad based regional perspective, we expect to develop a greater understanding of the role of ecological processes (fire regime, disturbance, thinning etc) on species richness and groundlayer restoration. We have initiated an experiment to determine the potential for oak savanna groundlayer restoration by interseeding on north and south slopes in relation to soil temperature and soil moisture. The groundlayer flora of oak savannas is quite rich in species, but removal of fire (suppression) causes the decline of the groundlayer flora through litter build up and shading. In addition, most savanna plant species lack a long term seed bank (viable seed buried in the soil) that would respond to restoration by germinating. Thus, in degraded sites, reintroduction of herbs and grasses may be the only way to enhance the groundlayer flora. In addition, north slopes may be important microhabitats for some oak savanna species during climatic extremes. These north slopes have been greatly altered through tree invasion after the removal of fire from the landscape. So we are investigating the potential for savanna species to occur on north slopes that may be moderated by climatic extremes but were some of the first sites to be invaded by trees as fire suppression commenced. Lastly, we have initiated five demonstration plots for impact of thinning on north slope groundlayer vegetation at the Indiana Dunes National Lakeshore. Sub canopy trees were cut and herbicided at each site to increase light levels and reduce tree density.