BACKGROUND Trees remove atmospheric carbon dioxide through photosynthesis, hereafter CO2 absorption (A). Despite growing urban green areas, only a few studies have quantified A of urban trees and assessed their dynamical changes with varying atmospheric conditions. Hence, we investigated A in nine dominant tree species in a new park of Bangkok. RESULTS Results revealed that A of two tree species (Millingtonia hortensis and Afzelia xylocarpa) significantly increased with vapor pressure deficit (VPD) until it reached a maximum and declined when VPD decreased, with no seasonal difference. Five of them (Dalbergia cochinchinensis, Tabebuia rosea, Lagerstroemia floribunda, Dipterocarpus alatus and Bauhinia purpurea) exhibited different response patterns of A to VPD between wet and dry seasons. In contrast, the A of two tree species (Samanea saman and Homalium tomentosum) did not respond to changing VPD in either season. CONCLUSIONS Comparing planting scenarios of insensitive (i.e. no response to VPD) versus sensitive (i.e. significant response to VPD) species, we found that planting a mixture of sensitive and insensitive tree species would improve the park's capacity of A across seasons, allowing climate change adaptation to adverse environmental impacts such as droughts and the urban heat island effects, and would increase biodiversity. Additionally, planting insensitive tree species would significantly increase the capacity of the park for CO2 mitigation. These findings are useful for those who design parks and expand urban green areas to fully benefit ecosystem services from trees.

中文翻译：

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在曼谷，泰国一个新公园中研究城市树木吸收二氧化碳的情况。

背景技术树木通过光合作用去除大气中的二氧化碳，此后吸收二氧化碳（A）。尽管城市绿化面积不断增加，但只有少数研究量化了城市树木的A并评估了它们在不同大气条件下的动态变化。因此，我们在曼谷的一个新公园中调查了9种优势树种中的A。结果结果表明，两种树种（Millingtonia hoortensis和Afzelia xylocarpa）的A随着蒸气压亏缺（VPD）而显着增加，直到达到最大值，当VPD降低时下降，没有季节差异。其中五种（Dalbergia cochinchinensis，Tabebuia rosea，Lagerstroemia floribunda，Dipterocarpus alatus和紫荆花）在湿季和旱季表现出不同的A对VPD响应模式。相反，两种树种（Samanea saman和Homalium tomentosum）中的A对两个季节的VPD变化均无反应。结论比较不敏感（即对VPD无反应）和敏感（即对VPD有显着反应）物种的种植情景，我们发现种植敏感和不敏感树种的混合物将提高公园A跨季节的能力，从而适应气候变化。受干旱和城市热岛效应等不利的环境影响，并会增加生物多样性。此外，种植不敏感的树种将大大增加公园减少二氧化碳的能力。这些发现对于那些设计公园并扩展城市绿地以充分利用树木的生态系统服务的人们而言非常有用。