Macroalgae and submerged macrophytes from fresh and saline waterbodies of ephemeral streams ('ramblas') in semiarid south-eastern Spain

Semiarid saline streams are uncommon and hence are seldom studied. Moreover , most studies on filamentous algae have been carried out in permanent fres hwaters. Seventeen waterbodies from ephemeral streams of semiarid south-eas tern Spain ('ramblas') were surveyed from a botanical, phycological and eco logical point of view over a four-year period. Gradients of environmental c onditions ranged from fresh to saline water (0.27 to 47 mS cm(-1)), from ep hemeral to permanent and from pools to streams. Most of the sites were spri ngs or streams that appeared in certain reaches as a result of the upwellin g of groundwater. In total, 47 species of submerged macrophytes and macroal gae were recorded, with 1-18 species per site. The most diverse orders were Zygnematales, Oedogoniales and Charales, although the importance and diver sification of Vaucheriales in some places was also of note. Multivariate an alysis identified salinity as the main factor explaining species distributi on. Conductivity ranges for species were compared with other saline habitat s such as saline lakes, saltmarshes or coastal lagoons. Finally, this study broadens the ecological range of some taxa and highlights the ecological i mportance of these kinds of systems for the preservation of biodiversity in arid lands.