Effects of microbiotic crusts on dew deposition in the restored vegetation area at Shapotou, northwest China

摘要

Information regarding dew deposition on microbiotic crusts is scarce in Chinese desert areas. An area of restored vegetation, where microbiotic crusts with different developmental levels are distributed in the revegetated enclosures of different ages, provides an ideal opportunity to study the hydrological issues related to the development processes of microbiotic crusts in a temporal sequence. The effects of microbiotic crusts on dew condensation were studied during the late summer and autumn of 2004. The results show that the amount of dew increases with the level of development of the microbiotic crusts. The physical crust, which is an initial form of microbiotic crust and is composed of sand with a higher proportion of clay and silt because of its aeolian origin, collects more dew than sand soil. In addition, the microorganisms adhering to the crusts cause the amounts of dew on the algae and moss crust to increase dramatically. ANOVA analysis results also indicate a significant difference between well-developed microbiotic crusts (algal and moss crusts), initial microbiotic crusts (physical crust) and sandy soil. It is potential that dew acts as a driving factor for restored vegetation succession through its benefits in the development of microbiotic crust. (c) 2006 Elsevier B.V. All rights reserved.