Publications

Cao, J; Han, HJ; Qiao, LL; Li, LY (2024). Biogenic Volatile Organic Compound Emission and Its Response to Land Cover Changes in China During 2001-2020 Using an Improved High-Precision Vegetation Data Set. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 129(18), e2023JD040421.

Abstract
Biogenic volatile organic compounds (BVOCs) are regarded as important precursors for ozone and secondary organic aerosol, mainly from vegetation emissions. In the context of the expanding trend of vegetation greening, the development of high-precision vegetation data and accurate BVOC emission estimates are essential to develop effective air pollution control measures. In this study, by integrating the multi-source vegetation cover data, we established a high-resolution vegetation distribution (HRVD) data set to develop a high spatio-temporal resolution emission inventory and investigated the impact of different land cover data sets on emission simulation and impact of land cover change on BVOC emissions during 2001-2020. The annual total BVOC emissions in China for 2020 was 15.66 Tg, which were mainly from trees. The emissions simulated by CNLUCC and MODIS data sets were 1.53% and 1.72% higher than those simulated by HRVD data sets, respectively. The spatial distribution of emission differences was consistent with that of land cover differences. The simulated BVOC emissions by the HRVD data set had the best accuracy as they improved the bias between modeling and observation from 69.06% to 65.35% and decreased the underprediction of observations by a factor of 2.13 compared with simulation by MEGAN default vegetation data. The annual BVOC emissions caused by changing vegetation distribution and LAIv (LAI of vegetation covered surfaces) enhanced at a rate of 72.06 Gg yr-1 during 2001-2020. LAIv was the main driver of emission variations. The total OH reactivity of the resulted BVOC emissions increased at a rate of 1.59 s-1 yr-1, with isoprene contributed the most. Biogenic Volatile organic compounds (BVOCs) are the key precursors of fine particulate matter and ozone, that mainly from vegetation emissions. To help to develop effective air pollution control measures in the context of expanding vegetation coverage for realizing carbon neutralization in China, it is urgent to develop highly precise vegetation data and accurately estimate BVOC emission. A high-resolution vegetation distribution data set was established through integrating multi-source vegetation cover data. Using it, the simulated annual BVOC emission in China was 15.66 Tg and mainly emitted from trees. Emissions from varied growth forms had different compound compositions. The BVOC emission simulated using the high-resolution vegetation distribution data set we developed had better accuracy than that using the single vegetation databases. The annual BVOC emissions caused by changing vegetation cover and leaf area index (LAI) enhanced at a rate of 72.06 Gg yr-1 during 2001-2020. LAI was the main driver of BVOC emission variations. The interannual variation and its spatial pattern of the OH loss rates of BVOCs during 2001-2020 were consistent with that of BVOC emissions, especially isoprene. Annual total BVOC emissions in China for 2020 was 15.66 Tg and emissions from varied growth forms had different compositions BVOC emission inventory simulated by the developed high-resolution vegetation distribution (HRVD) data set had better accuracy BVOC emission enhanced at a rate of 72.06 Gg yr-1 during 2001-2020 caused by land cover change, mainly driven by changing leaf area index

DOI:
10.1029/2023JD040421

ISSN:
2169-8996