Aims The objectives of this study were to investigate the effects of disturbance through wind erosion and sand burial on water relations and photosynthesis in Alhagi sparsifolia, and to determine the best habitat for the growth of A. sparsifolia in the southern edge of the Taklimakan Desert.
Methods We set up five treatments, including wind erosion depth of 10 cm, wind erosion depth of 5 cm, control, sand burial depth of 10 cm, and sand burial depth of 30 cm. Measurements were made on the concentration of photosynthetic pigments, chlorophyll fluorescence parameters, leaf water potential, and leaf water content in A. sparsifolia under different treatments on a sunny day.
Important findings Leaf water potential and leaf water content in A. sparsifolia m significantly decreased following the wind erosion treatments, thereby causing a reduction in the stomatal conductance, which in turn resulted in declining photosynthetic rate and transpiration rate. The water use efficiency in plants under the wind erosion treatments was lower than that under the sand burial condition, especially in the treatment of wind erosion depth of 10 cm. In addition, leaf water potential and leaf water content in A. sparsifolia were higher in the sand burial treatments than in the wind erosion treatments, which were associated with higher values of stomatal conductance, photosynthetic rate, transpiration rate, and water use efficiency. The maximum photochemical efficiency (Fv/Fm) in A. sparsifolia was suppressed under the wind erosion treatments, indicating increased stress suffered by the plants. However, A. sparsifolia may resist the adverse effects of wind erosion through increases in the number of active reaction centers and photochemical efficiency. The Fv/Fm in A. sparsifolia was higher under the sand burial treatments, indicating that the stress of A. sparsifolia suffered was alleviated. The absorption of light quantum yield and energy used for the photochemical reaction in the reaction center decreased increasing sand burial depth. This might be a survival strategy that A. sparsifolia adopted in response to the severe wind-blown sand environment. Compared with those in the treatments of wind erosion depth of 5 cm and sand burial depth of 10 cm, the growth of A. sparsifolia plants was significantly inhibited in the treatment of wind erosion depth of 10 cm, and significantly enhanced in the treatment of sand burial depth of 30 cm.