Monoterpenes emitted from trees play important roles in atmospheric chemistry through the formation of secondary organic aerosols and photochemical oxidants. Because monoterpene emissions from broad-leaved trees have rarely been studied in Japan, we measured the monoterpene emission rates of 20 Acer and 14 Fagaceae species. If a good correlation is found between the monoterpene precursor (geranyl diphosphate, GDP) content and monoterpene emission rate, the GDP content analysis in leaves may be an optional and simplified method to estimate monoterpene emission capacity of trees. To test this hypothesis, we investigated the relationship between GDP content in leaves and monoterpene emission rate of 13 tree species. Six Acer and 7 Fagaceae species were found to be monoterpene emitters. Although all of the measured trees contained GDP in their leaves, the presence or absence of monoterpene emissions was different for different species. Among the monoterpene emitters, no clear relationship was found between the basal emission rate (temperature: 30°C, photosynthetic photon flux density: 1000 μmol m⁻² s⁻¹) and GDP content. The ratio of the basal emission rate to GDP content differed between tree species. Our study demonstrated that the GDP content did not relate to the presence or absence of monoterpene production and its emission rate. We suggest that the activity or expression of monoterpene synthase may affect monoterpene emissions from Acer and Fagaceae species.

树木排放的单萜通过形成次级有机气溶胶和光化学氧化剂，在大气化学中发挥重要作用。由于在日本很少研究阔叶树的单萜排放，因此我们测量了20种宏cer和14种菊科植物的单萜排放率。如果在单萜前体（香叶基二磷酸香叶酯，GDP）含量和单萜排放速率之间找到良好的相关性，则叶片中的GDP含量分析可能是一种可选的简化方法，用于估计树木的单萜排放能力。为了验证这一假设，我们研究了13种树种叶片中GDP含量与单萜排放速率之间的关系。六宏cer发现7种菊苣科植物是单萜的发射体。尽管所有测得的树木的叶子中都含有GDP，但不同物种的单萜排放存在与否有所不同。在单萜发射体中，基本发射速率（温度：30°C，光合光子通量密度：1000μmolm ^-2 s ^-1）与GDP含量之间没有明确的关系。不同树种的基础排放率与GDP含量的比率不同。我们的研究表明，GDP含量与单萜生产的存在与否及其排放速率无关。我们建议单萜合酶的活性或表达可能会影响宏cer和菊科物种的单萜排放。