内蒙古河套灌区春小麦挥发性有机物排放特征

于2021年5月下旬至6月中旬,采用动态箱采样法对内蒙古河套灌区17种春小麦排放生物源挥发性有机物(BVOC)进行了研究,同时记录了温度、湿度和光合有效辐射(PAR)等参数.结果表明:内蒙古河套灌区春小麦主要排放异戊二烯、α-蒎烯和甲苯,生长期其排放率分别为(0.85~39.31),(2.60~14.32)和(6.41~35.39)ng/(g·h),成熟期其排放率分别为(1.75~7.99),(1.11~5.81)和(1.91~25.61)ng/(g·h);生长期异戊二烯、单萜烯类和BTEX标准状态(T=303K,PAR=1000µmol/(m²·s))下排放率分别为(12.92±5.14),(11.98±7.13)和(23.13±7.32)ng/(g·h),成熟期分别为(2.47±0.64),(5.73±1.19)和(14.23±5.27)ng/(g·h),生长期的排放率明显大于成熟期;一定环境温度和PAR范围内,河套灌区春小麦BVOC排放率与环境温度和PAR均呈指数相关,具有明显的日变化特征,但环境温度超过45℃时会抑制其BVOC排放率.

Emissions of volatile organic compounds from spring wheat in Hetao irrigation district of Inner Mongolia

A dynamic chamber system, with built-in air temperature, relative humidity and PAR (photo synthetically active radiation) data loggers, was employed to measure BVOC (Biogenic Volatile Organic Compounds) emissions from spring wheat from late May to mid-June 2021 in Hetao irrigation district of Inner Mongolia. The results showed that spring wheat emitted isoprene, α-pinene and toluene by (0.85~39.31), (2.60~14.32) and (6.41~35.39) ng/(g·h) respectively in the growth period and by (1.75~7.99), (1.11~5.81) and (1.91~25.61) ng/(g·h) respectively in the mature stage. The emissions of isoprene and monoterpenes, BTEX under normal conditions (T=303K, PAR=1000µmol/(m²·s)), were (12.92±5.14), (11.98±7.13) and (23.13±7.32) ng/(g·h) respectively in the growth period, and (2.47±0.64), (5.73±1.19) and (14.23±5.27) ng/(g×h) respectively in the mature period. Within certain ranges of temperature and PAR, BVOC emissions were exponentially correlated with ambient temperature and PAR, but would be inhibited when the air temperature exceeded 45℃.