When Water Availability Is Low, Two Mediterranean Species Rely on Root Hydraulics.

Increase in severity and frequency of drought events is altering plant community composition, exposing biomes to a higher risk of biodiversity losses. This is exacerbated in the most fragile areas as Mediterranean biome. Thus, identifying plant traits for forecasting species with a high risk of drought-driven mortality is particularly urgent. In the present study, we investigated the drought resistance strategy of two Mediterranean native species: Ard. () and L. () by considering the impact of drought-driven water content decline on plant hydraulics. Well-watered samples of displayed higher leaf and stemsaturated water content and lower shoot biomass than samples, but similar root biomass. In response to drought, showed a conservative water use strategy, as the prompt stomatal closure and leaves shedding suggested. A drought-tolerant mechanism was confirmed in samples. Nevertheless, and showed similar drought-driven plant hydraulic conductance (K) recover ability. Root hydraulic traits played a key role to reach this goal. Relative water content as well as loss of cell rehydration capability and membrane damages, especially of stem and root, were good proxies of drought-driven K decline.