Biogenic volatile organic compounds (BVOCs) serve as a critical link between the biosphere and the atmosphere, playing a vital role in atmospheric chemistry, ozone formation, and the creation of secondary organic aerosols. Volatile emissions from urban forest parks and greenery can have a significant impact on local and regional air quality. In this study, two common Ficus spp. plants with a high planting rate in Haikou were selected, and the BVOCs emissions of F. elastica and F. altissima were measured using the dynamic headspace bagging collection method and identification and analysis by gas chromatograph. The chemical components and emission characteristics of the BVOCs were also investigated. Meanwhile, the experiment continuously monitored environmental factors [temperature (T), photosynthetically active radiation (PAR)] and physiological parameters [stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr)] to further analyze the driving factors of BVOCs emissions in Ficus spp. The results showed 19 and 12 compounds identified for F. elastica and F. altissima. BVOCs emissions from Ficus spp. were dominated by isoprene and terpenoids. Among them, the relative content of isoprene emission from F. elastica increased by 1.82 times in the rainy season compared to the dry season, indicating that F. elastica has a significant potential for isoprene emission. The terpene compounds α-pinene and Caryophyllene made significant contribution. The daily variation of BVOCs in Ficus spp. showed a single-peak emission pattern of “low in the morning and low in the evening, high in the middle of the day”, with the maximum emission of BVOCs occurring at 12:00 or 14:00 noon, when the temperature or photosynthetically active radiation was the highest. BVOCs emissions from Ficus spp. were significantly higher in the rainy season than they were in the dry season. In addition, the BVOCs emissions of Ficus spp. were positively correlated with the temperature and with the photosynthetically active radiation. BVOCs emissions were positively correlated with the physiological parameters, Tr and Gs, and negatively correlated with Ci. This study expands the research field by investigating the emission characteristics of BVOCs from tropical Ficus spp. It provides essential data for enriching the database of BVOCs emission inventories in tropical and subtropical regions and for assessing their environmental impact.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |