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RECONDES - Case study

The case study related to “Cárcavo” catchment, located in northern Murcia province, Spain, was chosen as the main focus of work of RECONDES, and was reported for dissemination of information about the project.

The results of data analysing of connectivity show that the major areas of flow generation and connected pathways are associated with roads and tracks, areas of rock outcrops and thin soils, poorly maintained terraces, vegetated zones and macro- and micro-topography, particularly valley thalwegs. Erosion, in the form of rills and gullies, has been observed in all these zones.

During small-moderate rainfall events, most of the sediment is deposited onto slopes and only a little amount reaches the main channels. Much of the sediment in channels comes from channel erosion. The same connectivity pathways tend to redevelop on slopes in storms but with thresholds of occurrence related to different aspects: rainfall intensity and the spatial variability of localised conditions (land use, aspect, soil type, gradient and vegetation cover). Soil moisture content varies at micro scale and is higher under vegetation than in bare patches. Organic matter, aggregate stability and electrical conductivity are all significantly higher under vegetated patches indicating adaptation of soil properties by vegetation-related feedbacks.

Dominant species of plants and characteristic assemblages have been identified for the major land units on the marly substrates in SouthEastern Spain and zonations of plants within those land units have been recognised.

In reforested areas, soil evolution and vegetation recovery have been very slow, related to physical conditions, biological interactions or both. Seed banks are very low in reforested areas. Seed germination and seedling growth are inhibited by pine litter from the dominant species in the reforestation, Pinus halepensis.

Therefore, hotspots of erosion have been identified as locations for targeting for revegetation strategies and for most effective reduction of connectivity, erosion and prevention of gullying. The most suitable species for different zones have been established.

 

Source:
RECONDES Conditions for Restoration and Mitigation of Desertified Areas Using Vegetation. Specific Targeted Research or Innovation Project Sustainable development, global change and ecosystems Publishable Summary