Soil biodiversity in extreme environments

There are a number of terrestrial soil environments that can be considered extreme, from underground caves that stretch deep into the Earth, to cold or hot deserts (Fig. 3.38 and 3.39), and including the highest mountain tops. Many of these extreme organisms that have adapted physiologically to survive and perform critical ecosystem functions, such as biogeochemical cycling. Although extreme soil environments often support food webs that are limited in the number of species present, their diversity provides unique species and an often seperate gene pool for global biodiversity. Therefore, organisms of extreme ecosystems are viewed as valuable by many as a source for bioprospecting for commercial, medical or industrial use. Furthermore, recent evidence has shown that there is much to learn from extreme environments and their soils.