Soil Requirements of Four Salt Tolerant Species in Two Saline Habitats

In this paper we investigated the response to some edaphic factors of the guiding species in two habitats of interest for the European Union (Habitats Directive 92/43/EEC). For the priority habitat 1510 (Mediterranean salt steppes, Limonietalia), we chose Limonium cossonianum. For habitat 1420 (Mediterranean and thermo-Atlantic halophilous scrubs, Sarcocornietea fruticosi), we chose Arthrocnemum macrostachyum, Sarcocornia fruticosa, and Sarcocornia perennis subsp. alpini. We studied four coastal wetlands in the bay of Almeria (southeast of Spain), where we set up a grid of sampling plots. In each of these plots we related the presence of these species with a series of edaphic variables measured at specific times of the year for two years. Habitat 1510 is made up of moderately halophilous species that grow on soils that are saturated only in very wet weather conditions and cannot tolerate flooding for long periods of time. By contrast, the species of habitat 1420 are genuinely halophilous and the soils they grow on are often saturated and subject to frequent and prolonged flooding. The differences between these species are mainly rooted in different levels of tolerance to flooding-drying cycles (anoxia). Our results could be used as a criterion for the restoration of the habitats mentioned in the Habitats Directive, such as degraded salt marshes, and abandoned salt works, among others.