Subjects: Geosciences >> Geography submitted time 2023-12-16 Cooperative journals: 《干旱区研究》
Abstract: To reveal the survival strategy of plants in semi- arid coal mining subsidence areas faced with soil erosion stress, 2-3-year-old Artemisia ordosica plants were used as the test materials and in- situ root structure destruction tests were carried out at four levels: severe stress (P1), moderate stress (P2), mild stress (P3), and control (CK). The changes in growth indices, photosynthetic characteristics, and physiological traits of A. ordosica were measured. The results showed that soil erosion stress significantly inhibited the growth rate of A. ordosica, and that the greater the degree of simulated damage, the more significant the growth inhibition. After severe stress, the growth rates of plant height, crown width, branch length, and branch diameter of A. ordosica decreased by an average of 36.91%, 43.90%, 69.76%, and 66.76 %, respectively, compared to control plants. Soil erosion stress also conferred a significant negative effect on the photosynthesis of A. ordosica, and the greater the degree of damage, the stronger the negative effect. After severe stress, the net photosynthetic rate, stomatal conductance, intercellular carbon dioxide concentration, transpiration rate, and chlorophyll content of A. ordosica decreased by 39.86%, 59.26%, 7.82%, 51.55%, and 12.33%, respectively, compared to control plants. After 70 days of erosion stress, the activities of superoside dismutase (SOD), peroxidase (POD), and oxidoreductase (CAT) in A. ordosica initially increased and later decreased, and tended to be stable when compared with the control. The malondialdehyde (MDA) content fluctuated within a certain range. Redundancy analysis showed that the level of SOD activity had the most significant effect on the photosynthetic characteristics of A. ordosica. Comprehensive analysis showed that the root fracture of A. ordosica caused by soil erosion in coal mining subsidence areas will reduce its growth rate and inhibit photosynthesis. However, A. ordosica can maintain its growth by regulating the activity of its antioxidase systems and can therefore be considered to be an ecological restoration plant species due to its excellent resistance and adaptability in erosive areas