Fur Trade and the Biotic Homogenization of Subpolar Ecosystems

Abstract

At the southern end of the Americas exist one of the last pristine ecosystems in the world, the sub-Antarctic Magellanic forests ecoregion, protected by the Cape Horn Biosphere Reserve (CHBR). Despite its remote location, the CHBR has been subject to the growing influences of globalization, a process that has driven cultural, biotic, and economic transformations in the region since the mid-twentieth century. One of the most important threats to these unique ecosystems is the increase of biological invasions. Motivated by the expanding fur industry that responded to the globalization process, American beavers (Castor canadensis), muskrats (Ondatra zibethicus), and American minks (Neovison vison) were introduced, independently, to the southern tip of South America. Research has shown that these three North American species have reassembled their native interactions to affect negatively the invaded ecosystems of the CHBR. Beavers affect river flow and native vegetation, changing forests into wetlands, creating suitable habitats for muskrats. Muskrats, in turn, are the main prey of inland mink populations. The latter has major impacts by preying opportunistically on the native biota, especially native birds and small rodents. In this chapter, we explore this multi-species invasive system as an example of biotic homogenization, in which the introduction of these species and their subsequent reassembling of their interactions, together with the ecosystem impacts, offer a novel example of complex processes of biotic homogenization involving both biological and sociocultural dimensions.