Wang Hui, Nagalingam Sanjeevi, Welch Allison M, Leong Christopher, Czimczik C I, Guenther Alex B
Department of Earth System Science, University of California, Irvine, CA 92697.
Proc Natl Acad Sci U S A. 2024 Nov 5;121(45):e2412817121. doi: 10.1073/pnas.2412817121. Epub 2024 Oct 21.
Biogenic isoprene emissions from herbaceous plants are generally lower than those from trees. However, our study finds widespread isoprene emission in herbaceous sedge plants, with a stronger temperature response surpassing current tree-derived models. We measured and compared isoprene emissions from sedges grown in different climatic zones, all showing an exponential temperature response with a Q10 range of 7.2 to 12, significantly higher than the Q10 of about 3 for other common isoprene emitters. The distinct temperature sensitivity of sedges makes them a hidden isoprene source, significant during heat waves but not easily detected in mild weather. For instance, isoprene emissions from can increase by 320% with a peak emission of over 100 nmol m s compared to preheat wave emissions. During heat waves, the peak isoprene emissions from can match those from , a commonly used street tree species which is considered the dominant urban isoprene source due to higher biomass and emission capacities. This surge in isoprene from globally distributed sedges, including those in urban landscapes, could contribute to peak ozone and aerosol pollutants during heat waves.
草本植物的生物源异戊二烯排放量通常低于树木。然而，我们的研究发现草本莎草植物中普遍存在异戊二烯排放，其对温度的响应更强，超过了目前基于树木的模型。我们测量并比较了生长在不同气候区的莎草的异戊二烯排放量，所有结果均显示出指数型温度响应，Q10范围为7.2至12，显著高于其他常见异戊二烯排放源约3的Q10。莎草独特的温度敏感性使其成为一个隐藏的异戊二烯来源，在热浪期间很显著，但在温和天气中不易被检测到。例如，与热浪前的排放相比，[具体植物名称1]的异戊二烯排放量可增加320%，峰值排放量超过100 nmol m⁻² s⁻¹。在热浪期间，[具体植物名称2]的异戊二烯峰值排放量可与[具体植物名称3]相匹配，[具体植物名称3]是一种常用的行道树物种，由于其较高的生物量和排放能力，被认为是城市异戊二烯的主要来源。全球分布的莎草，包括城市景观中的莎草，异戊二烯的这种激增可能会导致热浪期间臭氧和气溶胶污染物达到峰值。
