Biogeochemical Responses in Acidified Forest Ecosystems

The intensification of acidic deposition from industrial and agricultural sources has altered nutrient cycles, soil chemistry and water dynamics in forest ecosystems worldwide. Acid inputs disrupt the balance of base cations such as calcium and magnesium, elevating aluminium mobilization and hindering biological processes. In response, forest soils exhibit changes in acidity, nutrient availability and carbon storage, while vegetation adjusts water‐use strategies and root morphology to cope with altered soil conditions. Liming and other mitigation techniques aim to neutralise acidity, improve nutrient retention and restore biogeochemical functioning. The interplay between soil chemistry, hydrology and biology determines the capacity of forests to adapt or recover, with implications for watershed hydrology, carbon sequestration and biodiversity conservation.

Research from Nature Portfolio

Recent studies have provided experimental evidence linking soil acidification to watershed hydrology. In a subtropical forest watershed, controlled acid additions revealed that increased soil acidity initially enhances plant growth and transpiration. Plants acclimate by intensifying water and nutrient uptake, thereby elevating evapotranspiration and reducing streamflow at the catchment scale. These findings underscore the need to integrate biogeochemical feedbacks into hydrological models to predict the impact of acid deposition on water resources and ecosystem resilience.

Biogeochemical Responses in Acidified Forest Ecosystems publication trend

The graph below shows the total number of articles in biogeochemical responses in acidified forest ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Acid deposition: The input of acidic compounds, chiefly sulphur and nitrogen oxides, from the atmosphere to terrestrial ecosystems.

Liming: The application of alkaline materials, such as limestone or dolomite, to increase soil pH and replenish base cations.

Base saturation: The proportion of soil cation exchange sites occupied by base cations (calcium, magnesium, potassium and sodium) relative to total exchange capacity.

Soil organic carbon (SOC): The carbon component of organic compounds in soil, representing a key pool in the global carbon cycle.

Cation exchange capacity (CEC): The total capacity of soil to retain and exchange positively charged ions on clay and organic matter surfaces.

Evapotranspiration: The combined process of water loss from soil evaporation and plant transpiration.

References

1. Streamflow decreases in response to acid deposition in a subtropical forest watershed in China. Communications Earth & Environment (2023).
2. Forest liming in the face of climate change: the implications of restorative liming for soil organic carbon in mature German forests. The Soil (2023).
3. Intensified vegetation water use under acid deposition. Science Advances (2019).
4. Have Sustained Acidic Deposition Decreases Led to Increased Calcium Availability in Recovering Watersheds of the Adirondack Region of New York, USA?. Soil Systems (2021).