】 The common habitat of bryophytes is restricted to dankness, but some bryophytes, such as the species of Pottiaceae, Grimmiaceae, Bryaceae and so on, are able to survive in arid and semi-arid areas with strong ability of drought tolerance. These bryophytes, in this sense, have to tolerate great heat and drought. Arid and semi-arid environments often support a low cover of vascular plants, which provide a niche for non-vascular plants such as mosses, lichens and liverworts. Under the pressure of extreme desic...