Optimizing In‐Situ Measurement of Representative BVOC Emission Factors Considering Intraspecific Variability

Abstract Accurately measuring emission factors ( E s ) of biogenic volatile organic compounds (BVOCs) with consideration of intraspecific variability is vital but often overlooked. This study presents in‐situ measurements of BVOC emissions from 114 Eucalyptus urophylla individuals using the LI‐6800 portable photosynthesis system. We observed intraspecific variability exceeding an order of magnitude in BVOC E s . Despite this variability, our approach yielded statistically representative E s for E . urophylla , yet challenging the feasibility of extensive field measurements. By quickly screening net photosynthesis rate ( P n ) across a broad set of individuals and selecting those within a specific P n range, such as mean ± 0.1 × SD (standard deviation) of P n for all screened individuals, for detailed BVOC emission measurements, we achieved comparable mean E s with approximately 10% of the original sampling effort. This offers a practical solution for efficient and accurate field measurement of representative BVOC E s , significantly reducing required sample size while effectively addressing intraspecific variability.