Sulfide as a soil phytotoxin-a review.

Area of Science:

• Environmental Science
• Ecology
• Biogeochemistry

Background:

• Sulfide, a phytotoxin, accumulates in wetland soils and sediments via microbial sulfate reduction.
• Its concentration varies with edaphic conditions in marine, brackish, and freshwater systems.

Purpose of the Study:

• To review the phytotoxic effects of sulfide across different ecosystem types and organizational levels.
• To synthesize knowledge on sulfide's impact on plant ecophysiology, plant-microbe associations, and community interactions.
• To highlight the importance of rhizospheric processes in understanding sulfide resistance and toxicity.

Main Methods:

• Literature review and synthesis of existing research on sulfide phytotoxicity.
• Comparison of studies across diverse wetland ecosystem types (marine, brackish, freshwater).
• Analysis of effects at individual plant, plant-microbe, and community levels.

Main Results:

• Sulfide profoundly affects plant fitness and ecosystem functioning in all wetland types.
• Rhizospheric interactions reveal complex mechanisms of sulfide resistance.
• Traditional toxicity tests often neglect crucial rhizospheric effects, limiting real-world applicability.

Conclusions:

• Sulfide is a significant phytotoxin impacting wetland ecosystems at multiple levels.
• Knowledge of biogeochemical, physiological, and ecological rhizosphere processes is vital for understanding sulfide's effects.
• Increasing anthropogenic sulfur and organic loads, coupled with climate change, may exacerbate sulfide production and impact.