Plant invasion modifies isohydricity in Mediterranean tree species

Understanding of plant hydraulic strategies (i.e., the degree of iso-/anisohydricity) is crucial to predict the response of plants to changing environmental conditions such as climate-change induced extreme drought. Several abiotic factors, including evaporative demand, have been shown to seasonally modify the isohydricity of plants. However, the impact of biotic factors such as plant-plant interactions on hydraulic strategies has seldom been explored. Here, we investigated adaptations and changes in hydraulic strategies of two woody species in response to seasonal abiotic conditions, experimental drought, and plant invasion in a Mediterranean cork oak (Quercus suber) ecosystem with a combined shrub invasion (Cistus ladanifer) and rain exclusion experiment. From the dry to wet season, Q. suber shifted from a partial isohydric to an anisohydric behaviour while C. ladanifer shifted from strict anisohydric to partial isohydric. During drought, water competition by plant invasion significan...