Abstract
Effects of soil water availability on seedling height, dry matter production and allocation were investigated for Khaya anthotheca (a typical species at drier sites in a moist deciduous forest) and Khaya ivorensis (a typical species at wetter sites in a moist deciduous forest). Two-month-old seedlings of the two species were subjected to three soil watering treatments, which were termed wet, moderate and dry treatment, in a glass house for 14 weeks. Seedling height growth was significantly influenced by soil water availability and the pattern of height response was species-specific. K. anthotheca had significantly better growth in the moderate watering treatment than in the wet and dry treatment. As time progressed, plants in the wet treatment of K. ivorensis had greatest height growth than in the moderate and dry treatment. Soil water deficit significantly reduced total dry matter production in K. ivorensis and altered proportional allocation to leaves and roots as a possible strategy for acclimation. Statistically, water deficit did not affect total dry matter production and allocation in K. anthotheca probably due to small sample size used in this study. However, in the moderate and dry treatments, K. anthotheca seedlings had greater total plant dry matter than K. ivorensis seedlings suggesting that the latter is more tolerant to water deficit and that K. anthotheca has considerable potential for plantation forestry in humid tropics of Africa with distinct drought periods.
