Deriving ecohydrological indicators in arid zones: the case of Ziziphus lotus in coastal aquifers. Ecohydrology and Hydrobiology (in revision).

Abstract

This study aims to relate the biological condition of Z. lotus with the groundwater condition to explore the feasibility for using vegetation indicators to inform about the salinization levels of groundwater in coastal aquifers. The results showed that leaf chemical composition of Z. lotus showed a strong relationship with the brackish groundwater level, the distance to the sea and therefore the groundwater salinity conditions. However, salinity levels were not reflected clearly in vegetation greenness (NDVI) and vegetation water content (NDWI), probably because of Z. lotus showed salt tolerance within the range of salinity found in the aquifer. As a conclusion, the leaf ion concentration as a good indicator of groundwater salinization, whiles the spectral indices are good indicators of vegetation health but not for the groundwater salinization.

Key words

Cabo de Gata-Níjar Natural Park, leaf chemical composition, NDVI, NDWI, Southeast Spain, Vertical Electrical Sounding.