Stress Memory in Cynodon dactylon (L.) Pers During Succession in Drawdown Zones: Implications for Vegetation Restoration and Sustainable Management

Reservoir drawdown zones are repeatedly affected by water-level fluctuations and anthropogenic regulation, making vegetation recovery an important issue for ecological restoration and sustainable reservoir management. This study focused on Cynodon dactylon, a dominant herbaceous species in the drawdown zones of five reservoirs in the Jinsha River Basin, southwestern China. Drawing on the existing concept of stress memory, which emphasizes the retained effects of previous environmental stress exposure on subsequent plant responses, we established an integrated assessment framework based on species dominance, functional traits, landscape pattern indices, and the soil seed bank. This framework was used to evaluate variation in the stress memory of C. dactylon across different successional stages and inundation gradients. The results showed that the overall stress memory of C. dactylon increased with successional progression in both the upper and lower zones, indicating continuous adaptive accumulation under long-term hydrological disturbance. The memory reflected by individual component indicators also generally increased, although their accumulation patterns varied among indicators. These findings suggest that dominance, functional traits, landscape pattern, and the soil seed bank can jointly characterize the adaptive responses of C. dactylon during vegetation recovery. Overall, the stress memory framework provides a systematic approach for identifying stage-specific vegetation changes, evaluating restoration potential, and informing ecological restoration and sustainable management in reservoir drawdown zones.