[en] Climate change, particularly the increasing frequency and intensity of drought events, poses a major threat to tree populations. In response, trees can adapt through various physiological mechanisms. Investigating xylem embolism resistance (P50) and the turgor loss point (Ψtlp) provides valuable insights into local adaptation and species distribution across environmental gradients. In this study, we examined how P50 and Ψtlp vary with micro-environmental conditions in a tropical rainforest in Gabon, focusing on closely related species of the Berlinia clade (Detarioideae).
We measured P50, Ψtlp, soil properties, topographic Index (TPI/TWI) on at least six individuals of nine closely related species from the Berlinia clade, along with their morphological characteristics and life-history traits.
By covering 27% of total variation of angiosperm P50 measurements, our findings revealed that embolism resistance is influenced by key soil properties associated with soil fertility, including cation exchange capacity (CEC), sand fraction, TWI and organic matter content. Notably, intraspecific variation exceeded interspecific variation, suggesting a high degree of local plasticity in P50 adaptation, likely driven by environmental heterogeneity.
Although well-studied in the Amazonian forest, P50 variation has never been explored in tropical rainforest of Africa until this study. Understanding the mechanisms governing drought resistance in tree species is crucial for predicting and modeling the future floristic composition of African tropical rainforests.
Research Center/Unit :
TERRA Research Centre. Gestion des ressources forestières et des milieux naturels - ULiège Laboratory of Plant Physiology “Coaracy M. Franco”, Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil Institute of Systematic Botany and Ecology, Ulm University, Ulm 89081, Germany 2Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium Evolutionary Biology and Ecology, CP 160/12, Faculty of Sciences, Université Libre de Bruxelles, Brussels, Belgium Plant Ecology and Biogeochemistry, CP 244, Faculty of Sciences, Université Libre de Bruxelles, Brussels, Belgium
