Deforestation by historical lime industry in an arid aeolian sedimentary system: An applied and methodological research.

Traditional land uses have been altering aeolian sedimentary systems for centuries through the removal of plant material for grazing, fuel or farming purposes. However, few studies have been able to quantify the deforestation process associated with these land uses due to the complexity that this entails and the limitations of the historical sources. In this context, the aim of this work is to develop a methodology that allows to reconstruct, evaluate, measure and locate the effects of deforestation processes. The methodology, based on the interpretation of historical documents, oral interviews and publications in the literature; was applied to a case study in Jandía (Fuerteventura, Canary Islands, Spain). On the basis of morphological measurements of the types of plant used to fire lime kilns, the current available biovolume was determined and an estimation made of the surface area affected by plant removal. The data obtained were integrated and analysed through a geographic information system (GIS) in order to quantify the impact of the lime kiln industry on the vegetation in the study area. The main results show that to fire a large-sized lime kiln oven it would be necessary to clear a low-density vegetation area of 21,826.08 m2 (or a a high-density vegetation area of 3075.72 m2) using three main species (Launaea arborescens, Lycium intricatum and Convolvulus caput-madusae). It was also found that distances of up to 38 km had to be travelled to obtain the vegetation required to fire the kilns. It is concluded that a number of impacts resulted from the demands of the limestone industry, particularly on plant communities, the abundance of certain species and flora richness, as well as modifications to geomorphological processes and the eventual collapse of the activity in the 1960s through overexploitation of the plant material. The present research allows us to learn from past experiences in which industries lacked proper planning and thus their activity led to their own collapse and rapid environmental degradation.

TEMPORARY REMOVAL: Sand, Sun, Sea and Sex with Strangers, the "five S's". Characterizing "cruising" activity and its environmental impacts on a protected coastal dunefield.

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Nebkha development and sediment supply.

This study examines the role of sediment supply in controlling the formation and the spatial patterns of nebkha, numbers and sizes, present in foredunes fronting coastal dunefields of the arid northwest African and the Canary Islands coasts. Sediment supply is estimated qualitatively and quantitatively by various measures, and the number and size of nebkhas are obtained on a range of beach-dune systems. In the case of the Canary Islands, LiDAR data and orthophotos with high spatial resolution (0.25 m) are used to measure sediment supply/activity, nebkha numbers and sizes, and vegetation variables, whereas data availability is less on the African coast. Results show that sediment supply exerts a major control on nebkha development such that as sediment supply increases, the number of coastal nebkha decreases, and the size of individual plants/nebkha increases. Once sediment supply is large, nebkha can only form on the immediate backshore if space is available, and a point is reached when the sediment supply is so large that nebkha do not, or cannot form. The data presented here provide two indicators which could be applicable to other dune systems. Firstly, by estimating the number of nebkha and the vegetation cover, the degree of aeolian sedimentary activity or sediment supply might be estimated. Secondly, the type of aeolian landform present provides a qualitative indication of sediment supply and aeolian activity.

Spatiotemporal analysis of the impact of artificial beach structures on biogeomorphological processes in an arid beach-dune system.

The research hypothesis considered in this study is that decisions adopted on beach use and management in arid environments can result in significant changes in the biogeomorphological processes of the beach-dune system of which it forms part. Different information sources and geographical information systems were used to make a spatiotemporal analysis of possible correlations between the presence of beach equipment, services and uses in the backshore area of an arid beach-dune system, such as the beach named Playa del Inglés (Gran Canaria island, Spain) and environmental changes detected in the same area. The period considered in the study covers from 1961 (before the development of the mass tourism on the island) to 2018. Significant variations in vegetation cover over the course of the study period were detected, as well as an overall increase in erosion (topographic and erosive aeolian landforms) and foredune fragmentation and a decrease in geomorphological resilience. The study found not only relationships between management decisions and environmental impacts, but also that environmental impacts of management decisions on beach use made in the 1970s and 1980s continue to be felt today. Moreover, the results also reinforce the idea that management decisions made based on the results of scientific research studies (management-research binomial) can lead to more environmentally sustainable actions.

Decadal monitoring of Traganum moquinii's role on foredune morphology of an human impacted arid dunefield.

Foredunes in arid zones have been little studied, being significantly different than tropical and temperate foredunes. In the case of the foredune of the arid Canary Islands' dune systems, Traganum moquinii is the predominant plant species, forms nebkhas and nebkhas fields, and acts as a structuring element in the dune field. In this work, the eco-anthropogenic evolution of the foredune surface, and the morphology and distribution of Traganum moquinii species in the Maspalomas dunefield (Gran Canaria, Canary Islands) are analysed, to understand the role that this plant species plays on the foredune's geomorphology and on the biogeomorphological processes altered by human actions. Eight variables were measured in 10 plots at five different times, from the 1960's to the present, through historical aerial photographs and orthophotos, integrated in a GIS. Significant decadal changes in the number and distribution/morphology of Traganum moquinii plants and also in the morphology of the foredune are observed, although not in a spatially homogeneous manner, as three different foredune behaviors are observed. The number of nebkhas/number of T. moquinii plants, has decreased between 1961 and 2012. The largest changes occurred in the north and south of the study area, and the lowest numbers of nebkhas occur where tourist activities and services are intense. In addition, the distance between Traganum moquinii individuals and variables measured in the foredune front (e.g. the diameter of the individuals) have significant relationships. Also, the greater the distance between plant individuals in the foredune front, the greater is the distance of T. moquinii individual plants in the rest of the plot. The alongshore variations in foredune development are due to natural processes (e.g. natural decline or growth of plants), and human impacts (e.g. carpark and kiosk construction, heavy tourist use). This research could be useful for the management of foredunes in arid regions.

Beach vegetation as an indicator of human impacts in arid environments: Environmental conditions and landscape perception in the Canary Islands.

Human occupancy of beaches is an important cause of environmental and landscape transformations, some of which are identifiable through vegetation analysis. Commonly, arboreal vegetation has been socially perceived in a positive way, as it contributes to the creation of environments appreciated as beautiful and natural. This type of vegetation has been recreated in urban coastal areas worldwide, including those located in arid environments where it is not always common or endemic to these areas. The typology of plant species, human impacts on beach environments, and the social perception of vegetation contrast were analyzed to understand the landscape influence and human impact on beach environments from arid regions. The study was carried out on 12 beaches with different degrees of human occupation (4 urban, 4 semi-urban and 4 natural) in Gran Canaria island (Spain). The results indicate that the number of exotic and ruderal (first to colonize human disturbed environments) species increases with human occupation of the beaches. A greater number of arboreal species were identified on urban beaches, while shrub and herbaceous species were more common on less occupied beaches (semi-urban and natural). However, when surveyed, the users of semi-urban and natural beaches, considered that arboreal vegetation compose a more attractive landscape than other with herbs or shrubs, even though tree species appear occasionally on these types of beaches. This inconsistency identifies a conflict of values between the development and conservation of beaches in arid environments. This study can be used to establish environmental sustainability strategies on beaches. Conservation and environmental information about ecosystem services related with indigenous plant species is and important issue for integrated management on beaches from arid regions, especially those that may be urbanized in the near future.

Biogeomorphological processes in an arid transgressive dunefield as indicators of human impact by urbanization.

Urban and tourist developments can have long-lasting impacts on coastal environments and fundamentally alter the evolution of coastal dune systems. This is the case of the Maspalomas dunefield (Gran Canaria, Canary Islands), hosting one of the largest tourist resorts in Spain. The resort was built on top of a sedimentary terrace at 25 m above sea level (El Inglés) in the 1960s, and has subsequently affected local winds and therefore aeolian sediment transport patterns. Buildings on the terrace deflect the winds to the south of the dunefield, where the rate of sediment transport accelerated. A shadow zone appeared to the lee side of the resort with a consequent decrease in wind speed and aeolian sediment transport and an increase in vegetation cover. In this paper, first we characterize the environmental changes around El Inglés terrace in recent decades, and describe the changes in the shadow zone through an analysis of the evolution of sedimentary volumes and vegetation characteristics (density, spatial patterns, and plants communities). A series of historical aerial photographs, recent orthophotos and digital elevation models obtained by digital photogrammetry and LiDAR, as well as fieldwork were used to characterize plant communities and spatial-temporal changes in erosive landforms. Results show changes in the pattern and migration rates of dunes located at the southern edge of the urbanization, as well as the formation of blowouts and large deflation areas, where the vegetation increases in density and number of plant communities. We discuss eco-anthropogenic factors that have produced these environmental changes.

Assessing the geomorphological vulnerability of arid beach-dune systems.

In this study, an arid dune vulnerability index (ADVI) is developed using a system of indicators to evaluate the geomorphological vulnerability of beach-dune systems of arid regions. The indicators are comprised of three analytical dimensions (susceptibility, exposure and resilience) and their corresponding sub-indices and variables and were assessed for eleven sites located in four aeolian sedimentary systems of the Canary archipelago (Spain). The selected sites have varying geomorphological characteristics, vegetation types, marine and wind conditions and human pressure degrees, and have seen different trends in their geomorphological evolution since 1960. The eleven sites were separated into three groups according to their different conservation status and different management needs, and the results of the ADVI dimensions and variables were compared and analyzed for these three groups. In general, the results obtained in the analyzed sites reveal that susceptibility and exposure dimensions are related to low-moderate values, while resilience was high. Only one site presented a state of critical vulnerability, due to the loss of its capacity to maintain its geomorphological function in recent decades. Given the lack of knowledge about geomorphological vulnerability processes in foredunes of arid regions, ADVI is the first approximation to geomorphological diagnostic in these environments and can be useful for managers.