The Process of Soil Desiccation under Haloxylon ammodendron Plantations: A Case Study of the Alxa Legue Desert, China

Abstract

Haloxylon ammodendron is a desert shrub widely used as a windbreak and for sand fixation, and it has achieved remarkable results in China. However, in desert areas, large-scale afforestation increases soil water consumption and forms a dried soil layer (DSL), the development of which seriously threatens the sustainable development of the ecosystem. In this study, soil moisture in the 0–400 cm soil profile was measured in selected 5-, 11-, 22-, 34-, and 46-year-old plantations of Haloxylon ammodendron plantations in Alxa Legue, China, and three soil desiccation evaluation indices were calculated—the soil desiccation index (SDI), DSL thickness (DSLT), and DSL soil water content (DSL-SWC)—to analyze the change pattern of the soil water content for different stand ages. The results showed that the shallow water layer (0–200 cm) was depleted sharply in the first five years of Haloxylon ammodendron plantation growth, but no DSL developed; the inflection point of soil water content change appeared after 10 years of growth, after which the shallow soil water was depleted and the drying process of the deep soil water content was significantly faster than that in the early growth period. The deep soil layer (200–400 cm) was depleted seriously after 22 years of afforestation, the soil drying phenomenon was obvious, and the DSL developed from the 172 cm soil layer. After 46 years of afforestation, the DSL was fully developed and the DSL-SWC was only 0.034 cm3 cm−3. Priority should thus be given to the use of less water-consuming shrub species; alternatively, after 5 years of growth of Haloxylon ammodendron plantations, certain water control measures should be taken to maintain the soil water balance.

Field irrigation using magnetized brackish water affects the growth and water consumption of Haloxylon ammodendron seedlings in an arid area

“…Haloxylon ammodendron is a perennial shrub that is widely distributed in the desert regions of Central Asia and the arid and semi-desert regions of Northwest China (Liu et al, 2011 ; Buras et al, 2012 ; Cui et al, 2017 ; Lü et al, 2019 , 2022 ; Zhou et al, 2022 ). H. ammodendron is planted over an area of 114,000 km 2 in China, mainly distributed in the Xinjiang Junggar Basin, Tarim Basin, the Alxa Desert in Inner Mongolia, Qinghai Qaidam Basin, and Gansu Hexi Corridor (Hong et al, 2019 ).…”

Soil–Plant–Water Systems and Interactions

“…Zhou et al [10] investigated how afforestation, especially the age of different forest plants, affects soil moisture contents while focusing on plantations with desert shrubs or small trees (Haloxylon ammodendron). The authors have developed different indices for soil desiccation evaluation.…”

Response of soil water content temporal stability to stand age of Haloxylon ammodendron plantation in Alxa Desert, China

“…In order to effectively curb wind and sand hazards and prevent the further expansion of sandy land, China has launched a number of major ecological construction projects in wind and sand hazards, such as the “3-North Shelter Forest Program” and the “Grain for Green” program with artificial vegetation construction as the main ecological restoration measure. The vegetation represented by Haloxylon ammodendron (HA) plantations is increasingly restricted by soil water content (SWC), especially as the large area of HA plantations has a more obvious soil drying phenomenon, which seriously affects the water cycle process in the study area ( Kang et al., 2021 ; Zhou et al., 2022 ). Therefore, it is important to understand the hydrological effect of SWC after afforestation for the water cycle and eco-hydrological process of terrestrial ecosystems.…”