Abstract
Stable soil pH is a key property in maintaining an ecosystem's structure, function, and sustainability. Increasing atmospheric deposition and grassland use on the Tibetan Plateau (TP) may increase the soil acidification risk, but we lack such information to date. Here, we evaluated the soil acidification risk in the TP, by comparing it with that in the Mongolia Plateau (MP) and applying the acid–base balance principles on atmospheric inputs, soils, and plants from 1980 to 2019. Cumulative acid input was lower in the TP than in the MP. Sulfur contributed more to acidity than nitrogen and atmospheric deposition contributed more to acidity than grassland use. Acid input was mainly influenced by local industry, animal husbandry and transportation in the MP, while in the TP it was also affected by the long-distance transportation of pollutants from South Asia and southern China. Overall, the TP was less acid-sensitive than the MP because of higher inorganic carbon content. However, soils in the southeastern TP, covering 21% of the total area, were acid-sensitive due to low levels of soil exchangeable base cation (EBCs) and lack of calcium carbonate. Coincidentally, the southeastern region has the highest concentration of acid input in the TP due to more rapid development and stronger influence of adjacent high acid deposition regions than others. Therefore, the acidification risk to the southeastern region is much higher than to other regions of the TP and the MP; in this region, the EBCs are likely to be depleted approximately 95 years earlier than in the MP. The findings of this study provide insights into the response of the TP to global change. For the ecosystem sustainability of southeastern TP, control of atmospheric acid deposition, especially sulfur deposition, in both local and adjacent regions and nations is required.
Highlights
Soil pH significantly influences soil biogeochemical cycles, biodiversity, productivity, and many other factors in terrestrial ecosystems (Chytrý et al, 2007; Kirk et al, 2009)
The average H+ input from atmospheric deposition during the 1980–2019 period was significantly higher in the Mongolian Plateau (MP) than in the Tibetan Plateau (TP); the proportion of the area of H+ input to the total grassland area was higher in the MP than the TP (56% vs. 25%)
The inputs of H+ from atmospheric deposition varied over time, and showed different patterns and magnitude (Fig S2 and S3)
Summary
Soil pH significantly influences soil biogeochemical cycles, biodiversity, productivity, and many other factors in terrestrial ecosystems (Chytrý et al, 2007; Kirk et al, 2009). The emission of NH3, which has strong acidification potential, has increased rapidly with the development of agriculture and transportation (Du et al, 2015). Increased use of grasslands or forests for, such as, grazing, mowing, and harvesting, has removed base cations from the soil and further exacerbated soil acidification (Bolan et al, 1991; Fujii et al, 2012). The exposure of terrestrial ecosystems to long-term high levels of anthropogenic acid input may lead to soil acidification and significantly change ecosystem structure and function (Chen et al, 2013a). Understanding the risk of soil acidification is important to maintain the stable and sustainable development of regional ecosystems
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
