Biogenic Volatile Organic Compounds (BVOCs) emissions from the forested areas in Turkey: determination of emission factors for endemic tree species

Emission factors of biogenic volatile organic compounds (BVOCs) from seven endemic tree species (Abies nordmanniana subsp. equi-trojani: Troy Fir, Abies nordmanniana subsp. bornmuelleriana: Uludag Fir, Abies cilicica subsp. isaurica: Cilicican Fir, Liquidambar orientalis: Oriental Sweetgum, Quercus macranthera subsp. syspirensis: Ispir Oak, Quercus aucheri: Boz Pirnal Oak and Quercus vulcanica: Vulcanic Oak) grown in Turkey were determined. A dynamic enclosure system was used to sample BVOCs where a branch was enclosed in a transparent Nalofan bag, maintaining natural conditions and avoiding any source of stress. Two branches of three different trees were sampled to produce average BVOC emission factors for each species. All meteorological and environmental parameters (temperature, relative humidity, Photosynthetically Active Radiation [PAR] and carbon dioxide) inside the chamber and in air were monitored and recorded. BVOCs were collected on adsorbent tubes (Tenax) from the inlet and outlet of the chamber. Sixty five BVOCs (in five groups: isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes and oxygenated compounds) were analyzed with GC/MS. All emission factors were normalized to standard conditions. Isoprene was the prominent compound for Cilicican Fir, Vulcanic Oak, Ispir Oak and Oriental Sweetgum while the others emitted mainly monoterpenes. Quantitatively, Ispir Oak, Oriental Sweetgum and Cilicican Fir were the highest BVOC emitters while Boz Pirnal Oak had the lowest emission rate. Oxygenated compounds were the third most prominent BVOC group and sesquiterpenes had slightly lower contributions. As mostly reported in the literature, coniferous and broad-leaved species emitted predominantly monoterpenes and isoprene, respectively.