The impact of drought stress on two medicinal plants in karst areas

Karst ecosystems are characterized by shallow soils, rapid water loss, and frequent seasonal drought, posing significant challenges to the growth and sustainability of medicinal plants.To investigate drought-induced morphological adjustment patterns in karst medicinal species, a controlled pot experiment was conducted using two representative plants, Bulbophyllum odoratissimum and Pyrrosia petiolosa.Five soil moisture gradients were applied to simulate increasing drought intensity.Key morphological traits, stomatal density, and root and aboveground biomass were measured to evaluate plant responses to water deficit.The results showed that increasing drought stress significantly affected all measured morphological indices and biomass parameters in both species (p