Seedling survival and growth of four forest tree species: the role of resource gradients in bottomland forests

The survival and growth of bottomland tree species in floodplain ecosystems are largely driven by species‐specific resource conditions. To assess the performance of native tree species along resource gradients, we planted seedlings of four native species, including Baldcypress ( Taxodium distichum ), Loblolly pine ( Pinus taeda ), Water oak ( Quercus nigra ), and Water tupelo ( Nyssa aquatica ), in southeastern Texas, United States, in 2019. Seedling survival and height were repeatedly monitored over 30 months following planting. The effects of soil texture, water table depth, soil pH, litter mass, light availability (both direct and diffuse), and leaf area index (LAI) on seedling survival and height were analyzed. Baldcypress exhibited the highest survival rate 30 months after planting (41.2 ± 2.7%, mean ± standard error). Baldcypress mortality was reduced with higher sand proportion ( r = −0.412, negative coefficients indicate reduced mortality risk), higher soil pH ( r = −0.304), higher diffuse ( r = −0.395), and direct ( r = −0.406) light proportion, and higher LAI ( r = −0.402). Water oak mortality was decreased by decreased direct light proportion ( r = 0.358). Water tupelo mortality was lower with decreased sand proportion ( r = 0.408), lower soil pH ( r = 0.367), lower direct light ( r = 0.627), and decreased LAI ( r = 0.311). The median survival times for Baldcypress, Loblolly pine, Water oak, and Water tupelo were 30, 4, 4, and 7 months, respectively. Diffuse and direct light availability, along with LAI, were key factors influencing height growth. In conclusion, species‐specific responses to soil texture, pH, and light availability can guide species selection for bottomland forest restoration. Understanding canopy structure and light availability helps optimize site preparation and resource allocation, reducing replanting risks and management costs.