Ramblas in south-east Spain: threatened and valuable ecosystems

Abstract

ABSTRACT1. The term 'rambla' defines watercourses with specific geomorphological features that make them different from all other temporary streams. Most ramblas represent extreme habitats for plants and animals that have to be adapted to high salinity and extreme hydrological fluctuations with severe dry periods and floods. Both factors shape the structure and functioning of the whole aquatic ecosystem.2. Biological communities in ramblas are diverse and rich in endemic species. Habitats of interest within the EU are extensively represented in ramblas and their associated wetlands. Ramblas also fulfil previously unrecognized functional and cultural values, such as helping to control non-pointsource pollution in agricultural areas and to provide a variety of historic and educational resources. However, they are a threatened ecosystem because of the diversity of uses and derived impacts.3. To characterize and describe the diversity of ramblas in south-east Spain, an extensive survey was carried out in 2000-2001 in the province of Murcia. Based on the lithology where ramblas are located, they were grouped in three categories: ramblas of marl, limestone and metamorphic basins.4. Rambla categories differ in structural parameters, hydrology, water chemistry, biological communities and their vulnerability to a range of human impacts, thus requiring a flexible approach to their management and conservation.

Non-perennial Mediterranean rivers in Europe: Status, pressures, and challenges for research and management

“…As a result, approximately 98% of the mapped water courses in the province of Murcia, which covers the driest part of the Iberian Peninsula, are NPRS (Gómez et al, 2005). Flow intermittency is further triggered by extended periods of low rainfall (Esteban-Parra et al, 1998) and high air temperature (De Castro et al, 2005).…”

“…Efforts have been made to estimate the spatial distribution and extent of NPRS at the country (Snelder et al, 2013;Mulas et al, 2009;Regione Siciliana, 2010;Fig. 2), regional (Gómez et al, 2005) and river basin scales Rosado et al, 2012), though overlap in definition of intermittent, ephememeral and episodic systems is an issue.…”

“…Pressures include agricultural land use, alien species, grazing, rubbish disposal, release of effluents, and habitat destruction such as through the use of NPRS as roads (Gómez et al, 2005;Suárez and Vidal-Abarca, 2008;Sánchez-Montoya et al, 2009). The response of various macroinvertebrate metrics to multiple stressor gradients typical for EU-Med streams, including NRPS ones, has been also studied (Munné and Prat, 2009;Sánchez-Montoya et al, 2010).…”

Regionalization of patterns of flow intermittence from gauging station records

“…For example, there are fewer restrictions imposed on the use or alteration of intermittent rivers in the United States compared with perennial rivers (Leibowitz et al, 2008). In much of the world, alterations of intermittent river channels and flow regimes are entirely unrestricted (Elmore and Kaushal, 2008;Gómez et al, 2005;Hughes, 2005). Effective management of intermittent rivers is impeded by the scarcity of information about their abundance, distribution patterns, patterns of flow variability, and the environmental conditions that produce those patterns Fritz et al, 2008;Hansen, 2001).…”

Nitrogen retention in natural Mediterranean wetland-streams affected by agricultural runoff

“…In the Southeast Iberian Peninsula (Spain), the presence of small wetland-streams is a typical feature of the Mediterranean landscape of sedimentary catchments (Gómez et al, 2005). These wetlands, which are associated with stream drainage systems, intercept the runoff waters originating from the agricultural catchments in which they are located.…”