Observation and Simulation of BVOCs Emission from Different Vegetation Types in Summer in China
WANG Chudi;JIE Longfei;LI Miaomiao;WANG Tianwen;GAO Kuo;LI Lingyu;College of Environmental Sciences and Engineering, Qingdao University;
Volatile organic compounds emitted by plants(biogenic VOCs, BVOCs) play an important role in the formation of atmospheric secondary pollution. To understand the BVOCs emission characteristics from different vegetation types in China, quantitative observations of monoterpene emissions from the plants of different vegetation types were conducted using the dynamic enclosure method and thermal desorption-gas chromatography-mass spectrometry(TD-GC-MS) technique. The MEGAN 2.1 emission model was applied to establish a high-resolution BVOCs emission inventory in summer 2018. The results showed that needle leaf trees had higher monoterpene emission rates than other plants, and terpinolene, cis-β-ocimene, limonene, and sabinene contributed the most. α-Pinene was the major contributor to monoterpene emission from broadleaf tree species. Monoterpene emission rates of crop, grass and shrub plants were dominated by terpinolene, trans-β-ocimene and limonene, respectively. The total emission of BVOCs in China in summer 2018 was 33.63×10~(12) g, with isoprene, monoterpene, sesquiterpene, and other VOCs accounting for 64.13%, 9.63%, 2.11% and 24.31%, respectively. Broadleaf trees had the highest contribution to the total BVOCs emissions(56.01%), followed by shrubs(14.16%). Summer BVOCs emissions were mainly distributed in northeastern, eastern, and Central China. The emission distribution of six vegetation types differed due to their different vegetation distribution. This study indicates that the monoterpene emission rates of plants by different vegetation types rank as needle leaf treebroadleaf treegrasscropshrub, which differ in composition of monoterpenes. The BVOCs emissions of each vegetation type rank as broadleaf treeshrubgrasscropneedle leaf treeconiferous and broad leaf mixed forest, which have distinguished BVOCs composition. Their spatial distributions are related to vegetation cover.