Disentangling water sources in a gypsum plant community. Tracing the use of gypsum crystalline water

Researcher: 
Ferrio Díaz, Juan Pedro
Congress: 
XV Congreso Nacional de la AEET
Participation type: 
Comunicación oral
Other authors: 
de la Puente L, Palacio S, Ferrio JP
Year: 
2021
Location: 
Palacio de Congresos de Plasencia, Cáceres, 18 - 22 de octubre de 2021
Publication: 
de la Puente L (speaker), Palacio S, Ferrio JP (2021) Disentangling water sources in a gypsum plant community. Tracing the use of gypsum crystalline water. XV Congreso Nacional de la AEET, Palacio de Congresos de Plasencia, Cáceres, 18 - 22 de octubre de 2021

The ability to access different water sources during drought is a key determining factor of the composition of gypsum plant communities growing on gypsiferous soils. Considering gypsum crystallization water as a potential source, we analyzed the principal water sources used by 20 species living in a top gypsum hill and the interaction of the plants with the soil beneath them, assessing differences between species with distinct root depths and gypsum affinities. We characterized water stable isotope composition, d2H and d18O, of plant xylem water and related it with the free and gypsum crystallization water extracted from the top 20 cm of the soil beneath each plant, from different depths along three one-meter-deep profiles and the groundwater, both in spring and summer. We observed a plant-soil interaction in spring, and indirect evidences of a possible hydraulic lift by deep-rooted species in summer. In spring, all species used free water from the top soil as the main source, but in summer, there was a segregation in the water sources, depending on the root depth, but not on the gypsum affinity of the species. While free water from 50-100 cm depth was the main source for the deep-rooted species, gypsum crystallization water was the main source for shallow-rooted species, dominant in the community. Crystallization water of gypsum represents an unaccounted, vital source for most of the shallow-rooted species, dominant in the community, and allows them to survive the arid conditions, contributing to more diverse communities.