Responses of African mahogany seedlings to temperature, vapor pressure deficit and water availability

The genus Khaya holds significant value in the national and international forest market due to its noble wood. However, the limited understanding of species-climate interactions hinders its expansion in Brazil. To address this, we investigated the effects of different microclimates on the growth of Khaya ivorensis , Khaya senegalensis , and Khaya anthotheca seedlings, considering variations in mean air temperature (T), vapor pressure deficit (VPD), and water availability. Seedlings were cultivated in controlled environments representing three microclimates (I: 24.7 °C, 0.30 kPa VPD; II: 28.6 °C, 0.95 kPa VPD; III: 29.8 °C, 1.80 kPa VPD) with varying water availability levels (20%, 40%, 60%, and 90% of maximum water holding capacity). Growth variables were assessed. Our findings indicate that water restriction reduced seedling growth across all microclimates, leading to lower total dry mass production. Specifically, K. ivorensis exhibited robust growth under microclimates with higher water availability. K. senegalensis displayed optimal initial growth in microclimate III (29.8 °C, 1.80 KPa), particularly when subjected to higher water availability levels in the substrate.