Browsing by Author "Wang, Chiao-Ping"

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    On the seasonality of long-range transport of acidic pollutants in East Asia
    (IOP, 2022-08-07) Chang, Chung-Te; Wang, Lixin; Wang, Lih-Jih; Liu, Chiung-Pin; Yang, Ci-Jian; Huang, Jr-Chuan; Wang, Chiao-Ping; Lin, Neng-Huei; Lin, Teng-Chiu; Earth and Environmental Sciences, School of Science
    East Asia currently has the largest SO2 and NOx emissions in the world. The long-range transport (LRT) of acidic pollutants in this region is of great concern but the extent is not well understood. Here results from combined long-term (⩾20 years) atmospheric deposition monitoring and air trajectory analysis in East Asia were reported. The results showed that despite the large decrease of SO2 and NOx emissions in Taiwan, annual deposition of non-sea-salt sulfate (nss-SO2−4 ) in northern Taiwan showed no decreasing trend during 1994–2020. However, when divided seasonally, both nss-SO2−4 and nitrate (NO−3 ) deposition had a significant decreasing trend in the summer but not in the winter. Similar patterns were found for Japan and Korea. Air trajectory models in combination with a regional emission map indicate that LRT from eastern China contributed up to 70% of the winter deposition of nss-SO2−4 and NO−3 in Taiwan and up to 50% in Japan and Korea. The results indicate that LRT obscured the efficacy of local pollution control measures in East Asia and suggest that transboundary air pollution regulations are required to combat acid deposition.
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    Precipitation controls on nutrient budgets in subtropical and tropical forests and the implications under changing climate
    (Elsevier, 2017-05) Chang, Chung-Te; Wang, Lih-Jih; Huang, Jr-Chuan; Liu, Chiung-Pin; Wang, Chiao-Ping; Lin, Neng-Huei; Wang, Lixin; Lin, Teng-Chiu; Department of Earth Sciences, School of Science
    Biological, geological and hydrological drivers collectively control forest biogeochemical cycling. However, based on a close examination of recent literature, we argue that the role of hydrological control particularly precipitation on nutrient budgets is significantly underestimated in subtropical and tropical forests, hindering our predictions of future forest nutrient status under a changing climate in these systems. To test this hypothesis, we analyzed two decades of monthly nutrient input and output data in precipitation and streamwater from a subtropical forested watershed in Taiwan, one of the few sites that has long-term nutrient input-output data in the tropics and subtropics. The results showed that monthly input and output of all ions and budgets (output – input) of most ions were positively correlated with precipitation quantity and there was a surprisingly greater net ion export during the wet growing season, indicating strong precipitation control on the nutrient budget. The strong precipitation control is also supported by the divergence of acidic precipitation and near neutral acidity of streamwater, with the former being independent from precipitation quantity but the latter being positively related to precipitation quantity. An additional synthesis of annual precipitation quantity and nutrient budgets of 32 forests across the globe showed a strong correlation between precipitation quantity and nutrient output-input budget, indicating that strong precipitation control is ubiquitous at the global scale and is particularly important in the humid tropical and subtropical forests. Our results imply that climate change could directly affect ecosystem nutrient cycling in the tropics through changes in precipitation pattern and amount.