Procesos biogeomorfológicos alterados por actividades antrópicas en sistemas sedimentarios eólicos costeros áridos

Resumen

The high level of anthropogenic pressure which occurs in coastal areas causes many of them to alter or lose their natural dynamics. The most immediate consequence is an increase in the vulnerability of the ecosystems that are located in these areas, and this in turn constitutes an added risk to processes potentially affected by climate change. The Canary Archipelago is one of the regions in Spain with the greatest dependence on the tourism sector, having specialized in mass sun and beach tourism. In this context, the coastal aeolian sedimentary systems of the Canary Islands have had to support anthropogenic activities in recent decades which in some cases have led to alterations to their natural functioning, and in others, to their disappearance. It can be deduced from the above that these modifications to the coastal dune systems of the Canary Islands can have two main consequences, one functional and the other socioeconomic. The first, which is dealt with in this research, is related to biogeomorphological impacts, that is to changes that are induced in processes which involve the joint interactions of plant species and aeolian sedimentary processes (aeolian landforms). These effects translate into changes to the ecosystems and the physiognomy of the space, as well as to the loss of ecosystem services. From an environmental point of view, it is most important to understand that the Canary dune systems are the only transgressive dune systems in arid regions in the whole of Europe. For their part, the socioeconomic consequences are related to the degradation of the characteristic landscape of these areas and, therefore, to a decrease in their appeal as a leisure and tourism destination. Considering this background, this doctoral thesis aims to define multiscale processes, both natural and induced by human activities (especially urbanization, infrastructure, services and users), related to geomorphology and vegetation in coastal aeolian sedimentary systems of the Canary Islands, as a model of such systems for arid regions. This article-based thesis includes six independent but thematically related works. The methodology and data used in these works have been adapted to different spatial and temporal scales. However, geographical information systems (GIS) are applied in all of them to measure variables related to the geomorphology, vegetation and anthropogenic activities of the dune systems studied. The variables are analyzed spatially and statistically to determine correlations between them, possible environmental changes and the origin of any environmental impact that is detected. The research is supported by 5 published papers and 1 paper under review. They are presented, in the context of this thesis, sequentially. In the first, a continental/global scale is used (Climate as a control on foredune mode in Southern Australia); in the second a regional scale (Urban-touristic impacts on the aeolian sedimentary systems of the Canary Islands: conflict between development and conservation); and in the last four local scales are used (Procedure to automate the classification and mapping of the vegetation density in arid aeolian sedimentary systems; Biogeomorphological processes in an arid transgressive dunefield as indicators of human impact by urbanization; Airflow dynamics, vegetation and aeolian erosive processes in a shadow zone leeward of a resort in an arid transgressive dune system, and; 2D decadal monitoring of Traganum moquinii's role in the morphometry of the foredune in an arid dunefield). The results show that environmental changes and the alteration of biogeomorphological processes become more complex as the spatial scale increases, but that it is at detailed scales that environmental changes induced by anthropogenic activities are best detected. As well as the extended use of basic science throughout this thesis to understand fundamental problems, a significant contribution is also made in terms of applied science: The results and information provided in each article are of particular relevance for management and planning (especially urban planning) decisions that have the potential to impact on arid coastal dune systems. This is particularly true for regions with arid coastal aeolian sedimentary systems that are currently being developed as tourist destinations.