Propuesta metodológica para la caracterización y tipificación de las costas españolas. Aplicación a las costas de Galicia.

There are several coastal classifications. Most of them have been elaborated worldwide using tectonic, climatic, topographic, or oceanographic criteria. Other classifications have been generated on a larger scale and focused on classifying the coastal forms, as cliffs, beaches, estuaries, lagoons, or dune complexes in different places.This project analyzes the types of coastlines, understanding as such each sector that presents certain topographic conditions marked by the elevation and slope, and that was modeled on a concrete type of rock in a specific climatic and marine environment. This paper describes a methodological approach for a detailed scale classification. This approach based on the delimitation of the different coastal systems, exemplified in cliffs and boulder beaches, sandy beaches, and dunes. In this case the shore platforms, marshes and lagoons have not been considered for the technical problems derived from the LiDAR data source, from which the 2 m spatial resolution digital terrain models (DTM) are derived.The first step in the classification was a manual delimitation combining DTMs and orthophotographs. Subsequently, other typification has been carried out through the automatic creation of Coastal Topographic Units (CTU). This index is the combination of two variables: coastal elevation and slope. The possible integration of others, such as orientation or lithology, is possible, but generate a very high number of units and make it difficult to interpret. For this reason, this study did not consider more variables.In this project 30 CTUs was generated, and then selecting only those that appear in the cliffs, boulder beaches, sandy beaches, and coastal dunes sectors. The possibility of viewing one or several CTUs in any sector of the coast allows to know more accurately the conditions of each sector and these categories could be improve the coastal management plans.

Dune(s): Fiction, history, and science on the Oregon coast

What connects the sci-fi book Dune with coastal dunes and geoengineering? The answer lies in humans and their world-making activities. This paper proposes an innovative approach to coastal dunes as hybrid environments by analyzing the dunes stabilization programs developed on the US Pacific Coast. It looks into the shifting sands of the Oregon coast and how they influenced Frank Herbert to write his novel, why local communities and federal authorities were interested in fixing the moving dunes and how these works ended up having unexpected consequences. It explores how human features acting as forcing mechanisms on beach-dune systems caused changes that turned into controlling influences in their own right, creating new environments and concerns. The paper ends with a reflection on how fiction and the history of dunes can be used to critically think about the anthropocentric hubris of building futures by geoengineering the planet for environmental repair.

Estate landscapes in the Netherlands

In the past, country house research was mainly concerned with individual houses and gardens. Yet, as early as the seventeenth and eighteenth centuries, so many country houses were being built around the major cities that they came to define the landscape. Genuine estate landscapes took shape along several rivers (Amstel, Vecht), along the inner edge of coastal dunes, and on newly reclaimed land. In the middle of the seventeenth century, the rivers were augmented with a network of barge canals and soon they too were lined by a belt of country houses. The greatest density of country houses was to be found around Amsterdam, but other big cities in the provinces of Holland and Zeeland had their fair share as well. Access was mostly by water, but in some areas, especially in Zeeland, country roads performed this role. The majority of country houses were built on or next to a farm, which generally continued to exist and, in many cases, survived the country house. In a few areas, the evolving density of country houses has been traced in a detailed chronological record. In most cases it reveals progressive growth towards a high point in the first half of the eighteenth century, after which a gradual decline sets in. However, in a number of areas growth was much more rapid, in particular along the River Vecht. Sustained growth was followed by decline. In the final decade of the eighteenth century and the first decade of the nineteenth, large numbers of country houses were demolished and in many instances the land reverted to agriculture production. It appears that the decline set in earlier in Zeeland than in Holland, but regional differences in decline are not yet entirely clear. The second quarter of the nineteenth century saw the construction of a new generation of country houses, especially in the undulating sandy areas of the Utrechtse Heuvelrug and the southern part of the Veluwezoom, where railway lines provided access. The owners of this new crop of country houses laid out their gardens in the English landscape style. They also bought up vast, neighbouring heathlands from local councils or farmers and planted them with trees. As a result, these country houses are quite different in character from those of the earlier period. In the past the concentrations of country houses dominated the landscape and even today, wherever they have survived to a substantial degree they continue to represent an important landscape quality. As such, protection and management should not be confined to individual country houses but should extend to groups of country houses and their interrelationships (in the form of visual axes, for example). In recent years, a number of provinces have already set a good example by formulating policies for country house biotopes and linear estate landscapes.

Exploring Temporal Trends of Plant Invasion in Mediterranean Coastal Dunes

Alien plants represent a significant threat to species diversity and composition in natural habitats. Nevertheless, little is known about the dynamic of the invasion process and how its effects on native species change over time. In this study, we explored vegetation changes that occurred in invaded coastal dune habitats over the last 10–15 years (2005–2020), particularly addressing impacts on alien and diagnostic species. To monitor temporal trends, we used data resulting from a revisitation study. After detecting overall changes in alien species occurrence and cover over time, 127 total plots were grouped into plots experiencing colonization, loss, or persistence of alien species. For these three categories, we compared historical and resurveyed plots to quantify changes in native species composition (using the Jaccard dissimilarity index) and to measure variations in diagnostic species cover. The number of alien species doubled over time (from 6 to 12) and two species, Yucca gloriosa and Agave americana, strongly increased their cover (+5.3% and +11.4%, respectively). Furthermore, plots newly invaded appeared to record the greatest changes in both native and diagnostic species. Our results suggest the need for regular monitoring actions to better understand invasion processes over time and to implement effective management strategies in invaded coastal dune habitats.

Fragmentation of Coastal Grasslands by Plantations and Spontaneous Spread of Invasive Pines in the Southern Pampa

Coastal dunes of the southern Buenos Aires province, in Argentina, are one of the last remnants of biodiversity in the southern Pampa unit, within the Rio de la Plata Grasslands. While the direct loss of grasslands due to the advance of cities and afforestation is conspicuous, the negative effects of the subdivision of the remaining environments on biodiversity and ecosystem dynamics are less considered. Our work aimed to analyze the combined effect of fires and subdivision of grasslands by invasive alien trees. Our results suggest that fragmentation affects the resilience of coastal grasslands after fire and affects the course of succession, promoting the establishment of invasive alien plants. We also suggest that fires favor the advance of pines and acacias towards the interior of grassland remnants, further reducing their area. The effective conservation of the components of Pampas biodiversity that still persist in these coastal ecosystems will depend on preventing, mitigating and compensating the insularization effects associated with forest plantations and the expansion of invasive trees, by means of adequate territorial planning that allows remnants to be maintained in a good state of conservation.

Ground-Penetrating Radar Prospections to Image the Inner Structure of Coastal Dunes at Sites Characterized by Erosion and Accretion (Northern Tuscany, Italy)

In this study we aimed to gain insights into dune formation and evolution from select coastal tracts of Northern Tuscany by inspecting their internal sedimentary architecture with Ground-Penetrating Radar (GPR) analysis. Erosion, equilibrium and accretion characterize the selected coastal tracts, and this analysis remarks on some GPR features consistently associated with specific coastal evolution states. A standard sequence of data processing made it possible to trace several radar surfaces and reflectors in the GPR profile, eventually interpreted in terms of depositional processes and erosive events. The stable or currently accreting coastal sectors show radar features compatible with a general beach progradation process, punctuated by berm formation in the general context of a positive sedimentary budget. Additionally, the radar facies distribution locally supports a mechanism of dune nucleation on an abandoned berm. Conversely, the GPR profile of the coastal sector today affected by erosion shows how a negative sedimentary budget inhibited coastal progradation and favored destructive events. These events interacted also with the active dunes, as demonstrated by the overlapping of wave run-up and aeolian radar facies. GPR prospections were effective at delineating the recent/ongoing coastal sedimentary budget by identifying radar features linked to construction/destruction phenomena in the backshore, and to dune nucleation/evolution.