Edaphic effects on forest structure and tree species composition in three seasonally dry tropical forest types in Cambodia

Soil conditions are critical factors shaping forest structure and tree species composition in seasonally dry tropical forests (SDTFs); however, few studies have evaluated edaphic effects in Cambodia's unique lowland forest landscape, where different forest types coexist under similar climatic conditions. Using tree census data from three adjacent 1‐ha plots in deciduous, semi‐evergreen, and evergreen forests in Siem Reap, Cambodia, we analyzed forest structure and species composition for each forest type. Soil nutrients and water content, measured at 0–200‐cm depth in both the rainy and dry seasons, were assessed alongside soil texture to evaluate edaphic influences. The tree census recorded 2551 stems from 130 species and 88 genera. Stem density and basal area were lowest in the deciduous forest, whereas species diversity peaked in the semi‐evergreen forest. Tree species composition differed significantly across forest types, with variation observed in dominant species compared with those in neighboring countries. High species turnover in Indochina SDTFs highlights the urgent need for conservation efforts in lowland Cambodian SDTFs. Soil nutrients and water content showed no significant differences among forest types in either season, except for higher water content in deciduous forest soils during the rainy season. Rainy‐season water content across all soil layers, along with clay and sand contents in deep soils, were significantly correlated with tree species composition. These findings underscore the importance of rainy‐season inundation in shaping forest structure and species composition in SDTFs.