Abstract:

This study aims to investigate the effects of different sand-fixation durations on desert soil seed banks and their relationship with aboveground vegetation. Using mobile sand dunes， straw checkerboard barriers （5-year fixation）， 37-year and 60-year sand-fixation sites as research objects， the characteristics of soil seed banks and aboveground vegetation as well as their interrelationships were systematically studied through a combined approach of aboveground vegetation surveys and soil seed bank germination experiments. The results indicate： （1） Both the soil seed bank and aboveground vegetation were predominantly composed of annual herbaceous plants， accounting for 71.43% and 54.55% respectively. With increasing sand-fixation duration， the species composition and density of the soil seed bank initially increased and then decreased， while the aboveground vegetation showed a different pattern； （2） The species diversity indices of the soil seed bank exhibited a unimodal trend （initial increase followed by decrease） with prolonged sand-fixation， whereas the diversity of aboveground vegetation demonstrated a continuous increasing trend； （3） The compositional similarity between soil seed banks and aboveground vegetation ranged from 0.28 to 0.07， showing a gradual decline with extended sand-fixation duration. Overall， vegetation-based sand fixation initially promotes soil seed bank accumulation and diversity enhancement， but long-term fixation may lead to ecological decoupling between seed banks and aboveground vegetation， necessitating artificial interventions to maintain sustainable ecosystem restoration.

Key words: vegetation sand fixation, soil seed bank, species diversity, species similarity, community succession