Dew formation characteristics at annual and daily scale in xerophyte shrub plantations at Southeast margin of Tengger desert, Northern China

Being a potential water source in arid and semiarid regions, it is important to quantify the amount of dew. The objective of this study was to determine the annual formation characteristics of dew and the influence of vegetation reconstruction on dew formation in a revegetated desert area. Effects of condensing surface types associated with different plant microhabitats were investigated. We found soil dew mainly depended on air water vapour near soil surface, and primarily formed at 0-3cm soil layer. Dew formed on 128days during a 1-year experiment period could be divided into 2 different periods; the monthly dew yield and the number of dew formation days were highest from May to October, and the cumulative dew yield of July and August accounted for nearly 50% of the annual dew yield. Biological soil crusts facilitated dew formation, with annual dew accumulation of 15.3, 11.9, and 9.6mm on moss crust, mixed crust, and dune sand, respectively. A longer daily dew production period was found on moss crusts than mixed crusts and dune sand. Plant microhabitats also influenced dew formation characteristics, less dew condense under plant canopies than on dune sand, but the daily dew production period was longer under plant canopies. The findings from this study will provide important and fundamental information to support accurate assessment of the relative importance of dew and rainfall in research on the hydrological cycle of this region, which will be a significant foundation for vegetation protection and ecological restoration in drought environments.