Understanding the ecosystem services provided by urban green spaces, in terms of their environmental, economic, and social benefits, is essential for a better management of area. Chulalongkorn University Centenary Park (CU 100) was established to mitigate the effects of climate change, especially flood prevention. This study focused on quantifying the ecosystem services provided by the trees in the park in terms of regulating and provisioning services. A publicly available tool, the i-Tree Eco international software, was used with data obtained from a local weather station as proxies to determine the accuracy of the analysis. Services, quantified in terms of monetary value, included avoided runoff, carbon storage, carbon sequestration, pollution removal, and timber price. The total monetary benefits, obtained from 697 trees (56 species, 49 genera, and 22 families), were estimated at USD 101,400. Of the total services, provisioning services contributed 75% to the total monetary value. Among all regulating services, the avoided runoff contributed about 60%, which was considered as the goal achieved by the park design. Azadirachta indica A. Juss (USD 518.75/tree⁻¹/year⁻¹), Shorea roxburghii G. Don (USD 417.17/tree⁻¹/year⁻¹) and Millettia leucantha Kurz (USD 414.87/tree⁻¹/year⁻¹) provided the greatest benefit, as indicated by a high value of provisioning services in terms of a high timber quality. These results can be used when planning the composition of trees to be planted in urban areas to increase both green spaces and maximize ecosystem services to improve the vitality of human well-being.

We present the results of classifying plants at species level that can tolerate air pollution, provide cooling, and simultaneously survive and thrive in urban environments. For this purpose, we estimated the air pollution tolerance index (APTI) and anticipated performance index (API) of several species growing in a park located in central Bangkok, Thailand. The cooling effect was quantified by calculating the reduction in soil and air temperatures. Melaleuca quinquenervia (Cav.) S.T. Blake, Albizia saman (Jacq.) Merr., Chukrasia tabularis A. Juss. had the highest API score and were able to substantially reduce the temperature and were in a group of highly recommended species which also included other species like A. saman, C. tabularis, Tabebuia rosea (Bertol.) Bertero ex A. DC., Dalbergia cochinchinensis Pierre etc. Species from both evergreen and deciduous habitat were able to provide ambient cooling but were vulnerable to air pollution and included Elaeocarpus grandifloras Sm. and Bauhinia purpurea L. However, there were other species which had a high air pollution tolerance but failed to provide adequate cooling, such as Hopea odorata Roxb. and Millingtonia hortensis L.f. The results would be of interest to urban greenspace landscapers in such climates while selecting suitable species that can provide multiple ecosystem services ranging from air pollution tolerance to temperature reduction without reducing plant vitality.

Climate change has become a prominent topic, particularly regarding plant adaptation and migration within mountain ecosystems. This study aimed to clarify forest dynamics by focusing on sapling and tree stages in relation to microclimate changes across a permanent plot along an altitudinal gradient. In 2012, a permanent transect plot (50 m × 600 m) was established at the forest ecotone between the deciduous dipterocarp forest (DDF) and lower montane forest (LMF). All trees with a diameter at breast height ≥ 1 cm were tagged, measured, and identified. Monitoring occurred every 2 years between 2012, 2014, 2016, and 2018, with a final census conducted in 2023. Microclimatic factors were recorded automatically, and rainfall data were obtained from a meteorological station. The dynamics of all trees were analyzed in relation to micro-climate changes. Our results showed that environmental changes significantly affected species coexistence, particularly in the forest ecotone between the DDF and LMF, where intermediate environmental factors were observed. High mortality rates were observed in the dominant evergreen species, with significant positive correlations with decreased rainfall and increased temperature, suggesting that drought conditions strongly influence tree mortality. In contrast, the deciduous species showed increased density, particularly in the forest ecotone zone, indicating their better adaptation to drought conditions and their potential to occupy the forest ecotone at a higher rate than LMF species. Understanding the ecological niches of coexisting species along altitudinal gradients is crucial for developing effective restoration programs in mountainous ecosystems.

El Niño’s impact on tropical forests is critical, as reduced rainfall and severe drought induced by this phenomenon affect species diversity and tree dynamics. As seedling is a crucial stage for forest regeneration to maintain population and species diversity in the forest, it is important to understand how El Niño-induced drought affects seedling dynamics. We monitored the seedling dynamics at monthly intervals for 7 years in a seasonally dry tropical forest (SDTF). We analyzed the differences in seedling recruitment and mortality during the El Niño and non-El Niño periods and compared two forest types in an SDTF: a deciduous dipterocarp forest (DDF) dominated by deciduous species, and an adjacent lower montane forest (LMF) with more evergreen species. The long-term data on seedling dynamics revealed that El Niño-induced drought triggered immense seedling mortality in both forest types. This effect was stronger in evergreen species, leading to higher mortality in the LMF during El Niño. However, El Niño increased seedling recruitment only in the DDF, mainly because of the massive recruitment of the deciduous oak, Quercus brandisiana (Fagaceae), which counterbalanced the seedling mortality in the DDF. Consequently, El Niño increased seedling density in the DDF while decreasing it in the LMF. Our findings showed that the El Niño-induced drought effects on seedling dynamics varied by forest type and leaf habit, suggesting that future changes in drought regimes may alter the species composition and spatial distribution of Asian seasonally dry tropical forests through differences in the response of seedlings to drought.