Drought- and Salt-Tolerant Plants of the Mediterranean and Their Diverse Applications: The Case of Crete

Abstract

Drought and salinity are two of the most urgent challenges faced in Mediterranean ecosystems, equally impacting natural systems, agricultural crops, and urban green. While many technical and soft approaches have been proposed to anticipate, mitigate, and remediate these impacts, a class of solutions has possibly been in front of us all along. Native Mediterranean fauna is well adapted, and when properly established still has unexploited conservation, restoration, and production diversification potential. Here, we outline the results of a long-term experiment taking place on the island of Crete, Greece that started in 1996 and involves over 70 native Mediterranean plants planted and monitored in various green spaces (private, shared, public) and a university campus under a diversity of adverse topographies (e.g., coastal, steep slopes), soils (e.g., disturbed, nutrient-deficient), and microclimatic conditions, taking various plant formations and serving various functions. After plant establishment, drought and salinity resistance were evaluated by gradually exposing plants (n = 5249) to deficit irrigation and saline environmental conditions, and plants were followed up for at least 5 years to empirically assess their ability to cope with abiotic stress. From the Mediterranean plants that were planted and tested, 52 were singled out because of their resistance and additional favorable traits. Motivated by this long-term assessment, a systematic literature review was conducted using the protocol Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) to validate empirical results, determine which were still unexplored, and bring to light additional uses. Results showed that 41 of the plants included in this research have significant medicinal properties, 26 have nutritional uses, 17 industrial uses, and 18 have evidence of cosmetology uses. Additionally, the empirical assessment gave new evidence of at least 40 new species–trait combinations. By formally documenting the characteristics of these native Mediterranean plants, this work highlights their versatile traits, and the prospect of creating new uses and value chains enables, for the first time their inclusion in planting-decision support systems and aims to increase demand and facilitate the scaling up of native greening in the context of sustainable land and water management within and beyond the Mediterranean basin.