Eco-geomorphological repercussions of recent climate dynamics on soil quality from Cabo de Gata-Níjar Natural Park (Almería, Spain)

In the Mediterranean area of southern Spain, a well-defined rainfall gradient is identified, ranging from 1.000-1.500 mm annual rainfall in the western sector to less than 150 mm in the extreme east. This fact implies a related impoverishment of ecosystem services, intensified by the impacts of current climate dynamics and leading to a degradation of soil-water-plant relationships and reflected in different indicator properties. In this respect, protected natural environments have a fundamental role to preserve and protect ecosystem services. Thus, the mitigation of the effects of climate change on them is a crucial challenge.  For this reason, this study has focused on the Cabo de Gata-Níjar Natural Park (UNESCO Global Geopark), located at the eastern end of the above-mentioned gradient, with territorial characteristics related to arid and semi-arid climatic conditions where the consequences of the current pluviometric pattern are emphasising the vulnerabilities of these areas. This research aims to (i) analyse the eco-geomorphological dynamics in last decades from a climatic and vegetation cover perspective and (ii) contrast this evolution with the soil quality situation, with emphasis on soil organic properties as determinants of the main degradation processes in the Mediterranean area. Methods used combine the statistical analysis of climatic variables based on data from the SAIH Hidrosur Network (1997-2022) with the use of spatial remote sensing techniques by applying vegetation indices in Sentinel-2 images. In addition, a total of 276 soil samples were collected and analysed to determine their physical, hydrological, and organic properties. On a preliminary way, the results show large differences between different landscape units. On the one hand, areas where abiotic factors control the current eco-geomorphological dynamics and where the aggressiveness of rainfall is causing important degradation processes, a reduction in the organic content of soils and, in general, a dynamic associated with rhexistasy, and on the other hand, areas where biotic factors are improving environmental conservation and the prevalence of biostasy processes.