Research data

This study investigates whether cyanobacterial inoculation can accelerate biocrust formation and mitigate wind erosion on dried seasonal wetland beds, with emphasis on the synergistic effects of inoculum density (0, 1.5, 3, 6 g m⁻²) and hydrological regime, completely dry (134 d) vs. dry–dewatering (60 d dry + 60 d submerged + 14 d dry). Soil (silt-loam, highly erodible) was collected from Kobi Baba Ali Wetland (Iran), and native Nostoc sp. and Oscillatoria sp., non-pathogenic, EPS-producing strains, were cultivated, dried, and applied via hydroseeding.

Biocrust development was assessed via two key indicators:
Chlorophyll-a (Chl-a), a proxy for cyanobacterial biomass and photosynthetic activity; Extracellular polymeric substances (EPSs), secreted polysaccharides that bind soil particles.
Wind erosion was quantified using a wind tunnel at 70 km h⁻¹ over three 10-min intervals (total 30 min), measuring soil loss rate (g m⁻² min⁻¹).

Key findings:
Uninoculated soil under dry–dewatering showed 39% lower erosion than under completely dry conditions, supporting Hypothesis i: even one wet–dry cycle enhances physical cohesion.
Cyanobacterial inoculation significantly boosted both Chl-a (up to +98%) and EPSs (up to +75%) versus controls. EPS increased at all doses (≥1.5 g m⁻²), but Chl-a rose significantly only at ≥3 g m⁻², indicating a biomass threshold for active crust maturation.
Under completely dry conditions, erosion decreased by 39%, 96%, and 97% at 1.5, 3, and 6 g m⁻², respectively. Under dry–dewatering, reductions were 64%, 94%, and 95%—highlighting synergy: low-dose inoculation (1.5 g m⁻²) performed markedly better with dewatering (+25% extra erosion control).
3 g m⁻² emerged as optimal: equivalent to 6 g m⁻² in efficacy (>95% erosion suppression) but more cost-effective.
Interpretation: Dewatering provides essential moisture pulses for cyanobacterial reactivation and EPS production, while inoculation jump-starts biocrust formation, normally slow (decades), within months. The physical (moisture-induced cohesion) + biological (filament entanglement + EPS gluing) mechanisms combine to form a resilient physical–biological crust.

Implications: For dried wetland management, timed inoculation (post-flooding) at 3 g m⁻² offers rapid, eco-friendly dust mitigation. Future work should address field scalability, long-term persistence, and ecological safety (e.g., bloom risks, non-target impacts).