Water characteristics and hydrological significance of Tamarix laxa distribution in the Mega Dune of Badain Jaran Desert.

Lake Group of Badain Jaran Desert and the recharge sources are hot issues in the academic community. The Mega Dune links the atmospheric precipitation and the lake water. Studying its hydrological characteristics could deepen the understanding of regional lake water cycle, while the plant distribution is an important indicator of the hydrological characteristics of the Mega Dune. This paper took the Tamarix laxa as the research object, measured the water content by drying method, analysed the spatial and temporal variation characteristics of the water content, then explored the indicative significance to the hydrological characteristics of the Mega Dune. The results showed: the soil profile of Tamarix laxa distribution area can be divided into moisture rapid change layer(0 to 60 cm), moisture active layer(60 to 120 cm) and moisture relatively stable layer(120 to 200 cm) according to its moisture characteristics, and the moisture content tends to decrease with increasing depth, and the average moisture content of rapid change layer is 1.69%, which is significantly higher than the other two layers. The water content of the distribution area is 95.83% in the range of 0.50% to 3.00% and the observed maximum value was 4.88%, all of them are less than the field water capacity(5.00%), which indicated that it was difficult to form gravity water in the Tamarix laxa distribution area at the leeward slope of the Mega Dune, but also indicated that the precipitation is difficult to quickly infiltrate to replenish lake water as gravity water for the leeward slope of the Mega Dune. The "arborization" growth characteristics of Tamarix laxa and its special distribution position are not only conducive to its root tiller propagation, but also to the storage and maintenance of water, which maintains its survival and development. [ABSTRACT FROM AUTHOR]