Relationships of tree height to diameter reflect multiple aspects of the species-specific strategy of growth and life history. For example, rapid height growth relative to diameter growth is advantageous for access to high light conditions, whereas thicker trunks enhance physical stability against stem breakage. In the natural forests of Ankarafantsika National Park, northwestern Madagascar, deciduous and evergreen broadleaf trees of various architecture coexist on a white-sand hill under a prolonged 6- to 7-month dry season. The forest has an overall low canopy of < 15 m probably due to the long dry season and the coarse sandy soil, yet it holds ca. 140 tree species reaching 5 cm in diameter at breast height (DBH) within a 15-ha monitoring plot. In this forest, we examined interspecific variations in height–diameter (H–D) relationships and explored their relationships with leaf and stem functional traits among the 22 most dominant species. The height of 945 trees without obvious stem breakage was measured, covering the DBH ranges from 1 cm to the maximum of each species. Species-specific H–D relationships with a two-parameter asymptotic model showed that the 22 species varied in H–D trajectories with their estimated maximal height ranging from 8.3 to 16.4 m. Hence, some of the most dominant species are emergent trees, while others would not reach the canopy. Principal component analysis revealed that some stem dimensional attributes were nearly orthogonal to leaf functional traits, indicating some independence between H–D relationships and the leaf economics spectrum. The initial slope of H–D models or the stem slenderness had no clear association with wood density, while three species with lower wood density had thicker trunks. For most of the dominant tree species, wood density is likely sufficient to ensure physical stability regardless of stem slenderness. The maximal height had a weak negative correlation with leaf mass per area. This weak correlation suggests the coexistence of species with diverse life-history strategies such as long-lived pioneers, shade-tolerant short trees, and slow-growing canopy trees. Further studies about tree crown dimensions and including shrub species will provide deeper insights into spatial and ecological niche differentiation and species diversity in the short-statured forest.