High ecostoichiometric stability and accumulating SiO2 and NO3− as main physiological adaptive mechanisms for reed to adverse environments

Previous studies have shown that nutrients accumulation played important roles in resisting to stress resistance of plants. Our study examined the ecostoichiometric internal stability (EIS) of nutrients accumulation and, concomitantly identified the main resistant regulating substances and their contributions to stress resistance of reed (Gramineae) in arid desert areas. Plants (digging method) and soil samples (quartering method)) obtained from sand dune (SD), desert steppe (DP), interdune lowland (IL), saline meadow (SM) and wetland (W) habitats were brought back to the lab for nutrients analysis. Results indicated that soil nutrients differed obviously, while reed maintained relatively stable ratios of SiO₂:N, N:K, and P:K when the eco-environments changed in different habitats. Furthermore, reed exhibits common adaptive characteristics by mainly accumulating large amounts of SiO₂ (122.6–174.0 g/kg) and NO₃⁻ (166.1–216.6 g/kg), as well as moderate levels of soluble sugar (SS: 24.0–55.0 g/kg), which are mainly stored in leaves for stress resistance. The contribution of ions to stress resistance was 80.03%–91.15% (with SiO₂ and NO₃⁻ accounting for 54.91%–63.10%), whereas the contribution of solutes was only 8.85%–19.97% (with SS contributing to 5.14%–10.91%) in different habitats. These findings suggest that maintaining relatively high EIS, while still accumulating SiO₂ and NO₃⁻ as main physiological regulators might be an effective strategy for reed to positively respond to adverse habitats, which provide a strong theoretical basis and technical reference for searching useful methods for restoration and reconstruction of the degraded ecosystems in desert oasis regions.