This dataset compiles leaf-level structural trait and tree allometric measurements collected along a tropical elevational gradient in the Colombian Andes across two common garden plantations with contrasting mean annual temperatures (MAT) (13.7 °C, 22.1 °C, and 25.5°C). Experimental sites have been named after their MAT. Sampling included trees from 15 dominant tree species at the 13.7 °C site, 10 species at the 22.1 °C site, and 4 species at the 25.5 °C site. At each experimental site, 360 juvenile trees (1-2 years old) from 15 dominant Andean species (11 montane and 4 lowland species) were planted in 2018/2019. All trees were planted in common soils originating from a high-elevation site and were regularly irrigated; By 2023, only 10 and 4 species remained at the 22.1 and 25.5 °C sites, respectively. Full details about this dataset can be found at https://doi.org/10.5285/fd793ac1-d990-4866-8586-3af7daced6dd
