Conserving Karner Blue Butterflies in Wisconsin: A Development of Management Techniques

Abstract

Crossing the Upper Midwest from northwest to southeast is an area known as the “tension” zone, a band of remnant open forests and grasslands associated with the sand deposits left behind during the last glacial retreat. The tree and other plant species found there are known as barrens and savanna grassland communities. Once one of the most abundant ecosystems in the Great Lakes Region, they have now decreased to scattered remnants of habitat in the years since European settlement (Curtis 1959; Grundel et al. 1998; Anderson et al. 1999; Swengel and Swengel 2005). Their demise has been so extensive that they are now considered globally imperiled. Today, as before, they are of critical importance to the survival of hundreds of species of both fauna and flora. Numerous management strategies have been developed and subsequently modified to restore and manage these communities in attempts to mimic the natural shifting mosaic of habitat that sustains these biological communities (Schweitzer 1990; Givnish et al 1988; Swengel 1998; Swengel 2001; Swengel and Swengel 2007). Over the last two decades, barrens management strategies have included prescribed fire, mechanical disturbance, chemical applications, and even grazing by …