Effect of Light Intensity on the Production of Volatile Organic Compounds by Submerged Macrophyte Vallisneria natans in Different Growth Periods

Biogenic volatile organic compounds (BVOCs) emitted by aquatic primary producers play an important role in carbon exchange processes and regional atmospheric chemistry, yet BVOCs production from submerged macrophytes remains poorly understood. In this study, we investigated the effects of growth period and light intensity on BVOCs production in the submerged macrophyte V. natans using a controlled experiment with three light treatments. The results showed that significant interactions between growth period and light intensity were observed for multiple BVOCs. The contents of most individual compounds decreased from the seedling stage to the mature stage and increased again during senescence. Light intensity significantly affected the production of several key BVOCs, including 2‐pentylfuran, phenylacetaldehyde, trans‐2, cis‐6‐nonadienal, and β‐ionone, with effects strongly dependent on growth period. Moderate shading promoted the production of 2‐pentylfuran and phenylacetaldehyde, whereas severe shading resulted in higher trans‐2, cis‐6‐nonadienal and β‐ionone concentrations. Overall, BVOCs production in submerged macrophytes is jointly regulated by plant growth cycles and underwater light intensities and cannot be reliably predicted based on a single factor, underscoring the importance of incorporating biological development and light‐driven variability into assessments of BVOCs emissions from freshwater ecosystems and their links to carbon cycling and atmospheric processes.