Regulatory Control and the Effects of Condensation Water on Water Migration and Reverse Migration of Halostachys caspica (M.Bieb.) C.A.Mey. in Different Saline Habitats

Abstract

Condensation water has been a recent focus in ecological hydrology research. As one of the main water sources that maintains the food chain in arid regions, condensation water has a significant impact on water balance in arid environments and plays an important role in desert vegetation. This study takes drought desert areas and high-salinity habitats as its focus—selecting Halostachys caspica (M.Bieb.) C.A.Mey. and its community in mild, moderate, and severe salinity soil—analyzed the source of condensation water utilized by these plants, and calculated its percentage of contribution. I. Study results revealed: (1) Scale-like leaves can absorb condensation water and the order of condensation water contribution to plant growth in different salinity habitats are severe > mild > moderate, such that the average contribution rates were 11.13%, 7.10%, and 3.79%, respectively; (2) The migration path of water movement in these three communities are formed in two main ways: (a) rain and condensation water recharge the soil to compensate for groundwater, while some groundwater compensates for river water and partially returns to the atmosphere by soil evaporation and plant transpiration; and (b) rain and condensation water directly compensate for river water and plant roots absorb river water, groundwater, and soil water in order to grow; (3) in mild habitats, the water movement path in plants is as follows: shallow root → stem → branches → leaves and shallow root → deep root; (4) in moderate habitats, stems act as the bifurcation point and the path follows as: stem → branches → leaves and stem → shallow root → deep root; and (5) in severe habitats, the path is as follows: deep root → shallow root → stem → branches → leaves, and finally returning to the atmosphere. These results elucidate the contribution of condensation water on Halostachys caspica growth and the migration path through the Halostachys caspica body. Condensation water obtained by Halostachys caspica communities in different salinity habitats provides a theoretical basis and data supporting the need for future research of condensation water on plants at the physiological level in arid regions and provides reference for the protection of saline soil and its ecological environment in arid regions.