Component Analysis Of Volatile Organic Compounds Emission From Grass Species And Their Dependence On Temperature And Light Intensity

Volatile organic compounds are various organic compounds with boiling point between 50 and 260~oC at room temperature,and they have two main sources:anthropogenic and natural emissions.VOCs came from natural emissions are called biogenic organic compounds,and they have been identified as derived from trees,grass species,paddy fields and other plant species.In this paper,a dynamic chamber system was employed to collected the biogenic volatile organic compounds from Leymus chinensis(Trin.)Tzvel,Agropyron cristatum(Linn.)Gaertn,Achnatherum splendens(Trin.)Nevski,Urtica acannabina L,Artemisia frigid Willd and Kochia prostrata(L.)Schrad in Xilingol grassland and the samples were qualitative and quantit-ative analyzed by thermal desorption gas chromatography-mass spectrometry from July 18,2017 to July 26,2017 after systematically studying the sampling techniques and analytical methods of biogenic volatile organic compounds.And the dependence of biogenic volatile organic c-ompounds emission flux on temperature and light intensity was also studied.The results:(1)qualitative analysis results:as for dominant species of Leymus chinensis(Trin.)Tzvel,Agropyron cristatum(Linn.)Gaertn and oth-er three grasses,twelve biogenic volatile organic compounds including i-soprene,alpha-pinene,beta-pinene,alpha-phellandrene,3-carene,alpha-ter-pinene,camphene,gamma-terpenes,beta-myrcene,terpinolene,para-cyme-ne and D-limonene were identified;And eleven biogenic volatile organic c-ompounds except beta-myrcene from Achnatherum splendens(Trin.)Nevski were identified.(2)quantitative analysis results:Leymus chinensis(Trin.)Tzvel and Agropyron cristatum(Linn.)Gaertn emitted isoprene,alpha-pinene,beta-pinene,alpha-phellandrene,3-carene,alpha-terpinene,camphene,gamma-terpenes,beta-myrcene,terpinolene,para-cymene and D-limonene with the emission fluxes of(578.8±92.4),(35.5±20.2),(23.6±5.6),(380.5±207.0),(15.7±4.7),(36.2±10.5),(173.4±202.0),(85.4±48.3),(17.6±3.3),(5.6±5.3),(62.4±10.4),(36.6±22.8)?g/(m~2·h)and(587.4±298.6),(7.2±0.3),(80.1±0.3),(204.5±122.1),(4.6±0.8),(10.0±3.3),(32.3±26.3),(63.0±27.5),(23.1±1.9),(7.3±5.1),(18.9±5.7),(4.5±4.4)?g/(m~2·h);Achnatherum splendens(Trin.)Nevski emitted isoprene,alpha-pinene,beta-pinene,alpha-phellandrene,3-carene,alpha-terpinene,camphene,gamma-terpenes,terpinolene,para-cymene and D-limonene with the emission fluxes of(397.2±364.4),(27.8±8.9),(10.6±5.1),(12.5±15.3),(2.9±0.6),(3.1±3.1),(10.2±7.9),(4.5±2.7),(0.3±0.1),(2.5±0.4)and(0.2±0.2);Urtica acannabina L,Artemisia frigid Willd and Kochia prostrata(L.)Schrad emitted isoprene,alpha-pinene,beta-pinene,alpha-phellandrene,3-carene,alpha-terpinene,camphene,gamma-terpenes,beta-myrcene,terpinolene,para-cymene and D-limonene with the emission fluxes of(273.9±107.3),(28.2±8.7),(38.2±16.2),(25.0±27.1),(2.6±0.5),(0.9±0.9),(2.3±3.3),(7.2±8.4),(1.6±1.1),(2.4±2.2),(0.1±0.1)?g/(m~2·h)and(391.6±264.3),(64.9±55.7),(34.5±20.7),(69.2±52.5),(7.8±6.7),(9.6±12.6),(34.2±25.4),(15.4±3.0),(70.8±154.0),(0.6±0.2),(49.9±66.3),(2.1±1.9)?g/(m~2·h)and(1236.8±1445.1),(1023.5±1380.1),(326.6±435.9),(68.0±22.6),(163.8±216.7),(8.8±10.7),(88.0±112.2),(17.6±7.2),(24.8±31.1),(1.1±1.0),(60.5±63.1),(9.9±11.8)?g/(m~2·h).Isoprene emission fluxes from different grass species,it's Leymus chinensis(Trin.)Tzvel,Agropyron cristatum(Linn.)Gaertn,Achnatherum splendens(Trin.)Nevski,Urtica acannabina L,Artemisia frigid Willd and Kochia prostrata(L.)Schrad in Xilingol glasslands at standard condition(T=30?,L=1000?mol/(m~2?s)were 257.28±93.51,369.73±194.87,226.40±110.15,325.96±346.63,248.15±208.49,681.71±944.31?g/(m~2?h),respectively.The emission fluxes of isoprene and alpha-phellandrene from Leymus chinensis(Trin.)Tzvel,Agropyron cristatum(Linn.)Gaertn and Artemisia frigid Willd were the most;The emission fluxes of isoprene and alpha-pinene from Urtica acannabina L and Kochia prostrata(L.)Schrad were the most;The emission fluxes of isoprene and beta-pinene from Achnatherum splendens(Trin.)Nevski were the most;The other volatile organic compounds were less.(3)During the sampling period,the volatile organic compounds emission fluxes from the six grasses showed obvious diurnal variation in a certain temperature range.The isoprene emission fluxes from Leymus chinensis(Trin.)Tzvel,Agropyron cristatum(Linn.)Gaertn,Artemisia frigid Willd and Kochia prostrata(L.)Schrad basically coincide with Guenther model.The results substantially improved the BVOC emission database of grassland ecosystem and would provide important scientific data for further research on the impact of BVOC emissions from Inner Mongolia grassland on the ozone formation process and for the research on organic aerosols in the atmospheric environment.