Spatio-temporal assessing of natural vegetation regulation on SO2 absorption coupling ecosystem process model and OMI satellite data

Abstract

Quantifying the contribution of natural ecosystems on air quality regulation can help to lay the foundation for ecological construction, and to promote the sustainable development of natural ecosystems. To identify the spatio-temporal dynamic changes of natural vegetation regulation on SO _2 absorption and the underlying mechanism of these changes in Qinghai Province, an important ecological barrier and the unique natural ecosystems, the Biome-BGC model was improved to simulate the canopy conductance to SO _2 and leaf area index (LAI) on the daily scale, and then the SO _2 absorption by vegetation was estimated coupling SO _2 concentration from satellite data. Our results showed that the annual average SO _2 absorption of the natural ecosystems in Qinghai Province was 4.74 × 10 ^4 tons yr ^−1 from 2005 to 2018, accounting for about 40% of the total emissions. Spatially, the ecosystem service of SO _2 absorption gradually decreased from southeast to northwest, and varied from 0 in Haixi state to 14.37 kg SO _2 ha ^−1 yr ^−1 in Haibei state. The annual average SO _2 absorption in unit area was 0.68 kg SO _2 ha ^−1 yr ^−1 , and significantly higher SO _2 absorption was observed in summer with 0.45 kg SO _2 ha ^−1 quarterly. The canopy conductance and LAI controlled by climate variables would be the dominant driving factors for the variation of SO _2 absorption for natural ecosystems. The sensitivity analysis showed that SO _2 concentration contributed more to the uncertainties of SO _2 absorption than the conductance in this study. Our results could provide powerful supports for realistic eco-environmental policy and decision making.

Keywords

• regulating service
• SO2 absorption
• improved Biome-BGC model
• OMI/SO2
• Qinghai province