Greenhouse gas emissions from riparian systems as affected by hydrological extremes: a mini-review

Abstract

Increasing atmospheric greenhouse gas (GHG) concentrations causes global temperature rising as well as extreme hydrological events. Understanding the effects of climate change-induced severe hydrological events such as flooding and drought on soil properties and subsequent GHG emissions from soil has enabled scientists to optimize different land management and global warming potential mitigation of a system. Flooding and drought dynamics affect soil physicochemical properties and GHG emissions specifically from land use systems that are adjacent to streams like riparian buffers. Drivers of soil GHG emissions and the effect of extreme hydrological events on the GHG flux from riparian systems in three climate zones (Mediterranean, temperate, and tropical/subtropical) were investigated in this review utilizing Web of Science and Scopus databases. Wet soil conditions contribute more to global warming (7.2 Mg CO₂eq-C ha⁻¹ h⁻¹) than dry soils (2.1 Mg CO₂eq-C ha⁻¹ h⁻¹) in riparian systems. Temperate riparian systems showed the greatest soil N₂O emissions (0.7 mg N₂O-N m⁻² h⁻¹) after flooding events/during wet seasons. The greatest CH₄ (12 mg CH₄-C m⁻² h⁻¹) and CO₂ (15.2 g CO₂-C m⁻² d⁻¹) flux from wet soils were observed in tropical/subtropical riparian systems. Greater soil inorganic N content (NO₃^- and NH₄⁺) in temperate riparian systems is responsible for the higher soil N₂O flux during wet seasons. Intense precipitation events and greater soil carbon content in tropical/subtropical riparian systems contributed to more CO₂ and CH₄ emissions relative to the temperate and Mediterranean riparian systems.

Keywords:

• Flooding
• drought
• land use
• soil moisture
• global warming

REVIEWING EDITOR:

• Tejada Manuel, Universidad de Sevilla, Spain

SUBJECTS:

• Soil Sciences
• Surface Hydrology
• Climate Change

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [Jamshid Ansari], upon reasonable request.