Effects of Acid Rain on Soil Microbial Communities and Ecosystem Dynamics

Acid rain, resulting from atmospheric deposition of sulphuric and nitric acids, profoundly alters soil chemistry and exerts cascading effects on microbial consortia and broader ecosystem processes. Lowered soil pH disrupts nutrient availability, mobilises toxic metal cations and reduces buffering capacity, thereby reshaping bacterial and fungal community structure. Sensitive functional groups—including nitrifiers, denitrifiers and lignin‐degrading microorganisms—often decline in abundance or activity, while acid‐tolerant taxa proliferate. Enzymatic processes such as urease, sucrase and ligninolytic enzymes are commonly inhibited, with consequences for nitrogen cycling, carbon turnover and soil organic matter stability. Changes in microbial network complexity and keystone taxa under acid stress can compromise resilience, leading to reduced soil respiration rates, altered litter decomposition and shifts in carbon sequestration dynamics. Such microbial responses vary with soil type, vegetation cover and acid rain intensity, but collectively they influence nutrient fluxes, greenhouse‐gas emissions and long‐term ecosystem health on a regional to global scale.

Research from Nature Portfolio

Laboratory experiments on purple rock substrates demonstrate that acidity accelerates the release of key cations (K⁺, Na⁺, Ca²⁺, Mg²⁺) via enhanced chemical weathering. An exponential relationship between H⁺ concentration and cation release rates was observed, indicating that ongoing acid deposition will intensify mineral dissolution. This shift in soil mineralogy not only alters base‐cation availability and soil pH but also reshapes the habitat for microbial colonisation. Increased cation leaching can exacerbate acidification in overlying soils, imposing stress on sensitive microbial guilds and amplifying downstream effects on nutrient cycling and plant–microbe interactions.

Effects of Acid Rain on Soil Microbial Communities and Ecosystem Dynamics publication trend

The graph below shows the total number of articles in effects of acid rain on soil microbial communities and ecosystem dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Acid rain: Precipitation with elevated acidity (pH < 5.6) due to dissolved sulphuric and nitric acids.

Nitrification: Microbial oxidation of ammonia (NH₃) to nitrite (NO₂⁻) and nitrate (NO₃⁻), critical in nitrogen cycling.

Denitrification: Biological reduction of nitrate or nitrite to gaseous nitrogen (N₂, N₂O), returning nitrogen to the atmosphere.

Keystone taxa: Species or groups exerting a disproportionate influence on community structure or function relative to their abundance.

Network complexity: The architecture of microbial interactions, described by nodes (taxa) and edges (associations), reflecting community stability.

Hydrochemical factors: Physical and chemical properties of soil water (pH, ion concentrations, redox potential) that govern microbial habitats.

References

1. Effects of simulated acid rain on hydrochemical factors and microbial community structure in red soil aquifers. RSC Advances (2024).
2. Higher Sensitivity of Soil Microbial Network Than Community Structure under Acid Rain. Microorganisms (2021).
3. Nitric Acid Rain Increased Bacterial Community Diversity in North Subtropical Forest Soil. Forests (2022).
4. Acidic condition accelerates cation release from purple rock in Southwestern China. Scientific Reports (2022).