Biodiversity Islands at the World’s Southernmost City: Plant, Bird and Insect Conservation in Urban Forests and Peatlands of Ushuaia, Argentina

Abstract

Ushuaia, a coastal city located in Patagonia, Argentina, amid unique natural habitats such as sub-antarctic Nothofagus forests and Sphagnum peatlands, preserves green areas of natural ecosystems within the urban matrix. Forests and peatlands have persisted as natural islands of different sizes, conservation status and anthropic disturbances. These urban green areas are underappreciated and administratively abandoned, and several threats could lead to their irreversible transformation (e.g., replacement by new neighborhoods, urban waste deposits). However, natural green urban areas can serve as biodiversity islands that make substantial contributions to conserve local biota and also to house new species assemblages (different from those in pristine areas), bringing native forest and peatland species closer to the local residents and visitors. These green urban islands can also help to preserve traditional cultural values, enhance education and generate local touristic attractions. In this chapter, we assessed the assemblages of plants and birds in urban native forests, and plants and insects in urban peatlands of Ushuaia city considering two levels of urbanization surrounding these green areas, and analyzed their variations compared with assemblages in nearby similar non-urban (low level of disturbance) ecosystems. Despite some differences in richness, abundance, biodiversity indices, and species composition of vascular plants, birds and insects, natural urban and peri-urban forests and peatlands still conserve several species and characteristics similar to those of unmodified ecosystems. However, the presence of new species, mainly plants, introduced into these urban patches has modified the original communities, establishing new assemblages that may contribute positively to urban biodiversity islands.