Higher soil acidification risk in southeastern Tibetan Plateau

Area of Science:

• Environmental Science
• Soil Science
• Ecology

Background:

• Stable soil pH is crucial for ecosystem health and sustainability.
• The Tibetan Plateau (TP) faces potential soil acidification risks from increased atmospheric deposition and grassland use.
• Limited data exists on soil acidification in the TP.

Purpose of the Study:

• To evaluate the soil acidification risk in the TP compared to the Mongolia Plateau (MP).
• To analyze the factors influencing acid input and soil sensitivity.
• To provide insights into the TP's response to global change.

Main Methods:

• Applied acid-base balance principles to atmospheric inputs, soils, and plants from 1980-2019.
• Compared acid input and soil sensitivity between the TP and MP.
• Assessed the role of inorganic carbon, exchangeable base cations (EBCs), and calcium carbonate.

Main Results:

• Cumulative acid input was lower in the TP than the MP, with sulfur deposition being a major contributor.
• The TP is generally less acid-sensitive than the MP due to higher inorganic carbon content.
• Southeastern TP soils are acid-sensitive due to low EBCs and lack of calcium carbonate, facing higher acidification risk and earlier EBC depletion.

Conclusions:

• The southeastern TP faces a significantly higher soil acidification risk than other regions.
• Ecosystem sustainability in the southeastern TP necessitates controlling atmospheric acid deposition, particularly sulfur.
• Findings highlight the TP's vulnerability to global change and the need for regional and international cooperation on pollution control.