2.5 Dune landscapes
Generally the beaches affect those who go to the beach for fun; it may seem unexpected that they have great value also from a naturalistic point of view.
The term dune indicates a buildup of sediments due to the action of the wind (FIG1_SES2.5); the presence of the vegetation allows its balance and consolidation, unfortunately, it’s disappearing throughout the Mediterranean due to the massive anthropization of the coasts.
The function of the dunes (FIG2_SES2.5) is to defend the coasts from erosion; they are covered in vegetation that holds the sand that would otherwise be transported away by the action of the wind and the waves. The dunes, moreover, represent a precious environment to nest and shelter for many birds, small mammals and reptiles as well as hosting an incredible variety of plants.
In the dune belt closest to the sea we have the so-called pioneer species. These are species with a short life cycle. An example can be the Cakile maritimo (FIG3_SES2.5).
In the most backward band, we can see the presence of perennial grasses, like Elytrigia.
The dunes of the inner band are more protected from storms, the deposition of sand from the wind is less, as well as the erosive processes. Here there is a vegetation of psammophile species that can vary depending on the geographical area. Crucianella maritima and Scabiosa argentea are some examples.
The “psammophile” plants, call the plants of the sands, have adopted particular adaptations:
– always live at a level higher than the high tide, so to be submerged by waters only occasionally and for very short periods
-Some have developed many roots in order to reach deep fresh water, which is scarce in surfaces, while others have long horizontally roots in order to collect much rainwater
– have a remarkable resistance to salt.
– are low or have a prostrate posture to oppose a limited resistance to the wind.
– produce sprouts at different heights to avoid complete burial by the sand carried by the wind.
– have leaves with a light color to protect themselves from the sun’s rays.
-The surface of the leaves reduced to the minimum to avoid excessive transpiration.
– have systems of water accumulation in the leaves, which often have a fleshy appearance (crassulence).
2.5.1 Anthropization: definition and meaning
The anthropization can be defined, in ecology, as the intervention of the human genre on the environment and the nature, to adapt it and change it according to its own needs. Although it is finalized to improve the quality of life, it doesn’t always have a positive impact; on the contrary, it often has ecologically harmful and irreversible effects on the biological equilibrium of the ecosystem. Obviously, as it is closely associated with the presence of men, it appears together with them already in the Pleistocene. However, that was still a minimal human influence. The anthropization will start to cause serious problems only after the industrial revolutions, reaching its peak in our days. Nowadays, some examples of anthropization are urbanization, deforestation, construction of agricultural and industrial installation or even the appearance of seaside resorts in the coasts. Anthropization has now become synonymous with pollution, since men tend to exploit and drain totally the resources they possess, without worrying about the future and acting as if they had another stock planet. In the long run it leads to drastic consequences such as the emission into the atmosphere, the soil or the waters of substances harmful to humans and to every other living organism and the onset of climate changes at the local and global level due to the increase of the greenhouse effect. In the past years the severity of the consequences of the anthropization has been underestimated and even now many try to belittle them for their own interests. But now, more than ever, it is essential that we take rigid measures to stop what is going to waste the entire earth.
2.5.2 Dune conservation: what can we do?
A dune is an accumulation of sandy sediment that forms along the coasts or in the desert areas, and it is the seat of transport and deposition of residues produced by wind, that is, determined and shaped by the action of the winds, and therefore subject to continuous displacements and changes that depend on the direction and strength of the wind.
The dune creates a reserve of sand that feeds the beach when it is subjected to erosive processes, therefore constitutes a natural defense of the coast and also represents a habitat of important naturalistic and landscape value. Consequently, the actions aimed at defending the dunes are particularly necessary for the defence of the coasts.
Natural processes and anthropic factors have favoured coastal erosion: the sandy coasts, made up of debris materials and due to swell and sea currents, are subject to continuous evolution.
Urban sprawl for residential and tourist purposes has reduced runoff areas. To try to preserve the integrity of the dunal system it would be appropriate to adopt appropriate intervention strategies. In particular: the revival or limitation of mechanisms responsible for the disturbance and degradation. The activation of ecological maintenance of the Dunale environment. The reconstruction of the dune cords and the realization of works aimed at facilitating the crossing that should be able to promote the increase of the dynamic stability of the beach-dune system, such as sand deposition processes, settlement of pioneer species. This innovative approach has the advantage of reducing the mass of these residues, which are usually removed from the beaches through cleaning activities, and to fertilize the sediment while maintaining the highest moisture content within the dunes. The safeguard of the dune system is a fundamental step in order to exploit the coastal heritage and promote a tourist development respectful of the natural resources of the territory.
2.5.3 The dune environment, home of Acanthodactylusschreiberi(description and characteristics).
Now we can talk about the dune environment and the home of Acanthodactylusschreiberi. The dune environment is an accumulation of sandy sediment of origin eolic, that is determined and modeled by the action of the winds. The dunes are hilly structures, characteristics of the deserts and the sandy coasts. Those coastlines parallelly develop to the shore, and they depend on the dimension of the beach from the dimensions of the granules of sand and from the strength of the winds.
The dune is formed by two sides:
• anterior side, directed toward the direction of movement of the dune with inclination more accented;
• back side, directed toward the direction of origin of the wind with lower inclination.
The top of the dune is defined crest.
A first classification of the dunes can be made on their form:
If in a dune there is one of these forms, it is simple; if in a dune we have more than two forms, it is composed or complex.
Acanthodactylus schreiberi is a species of lizard in the family Lacertidae. The natural habitats of Acanthodactylus Schreiberi are sandy shores, pastureland, and plantations. The beach starts some meters before the shoreline, that is in the zone of interval between the low one and the tall tide where the waves break it. After the shorelone the beach always begins and follows even more a profile of increasing height up to the first dunes of elevated sand. In the beach a lot of plants, without which the grains of sand would be transported more easily by the wind ,grow.
2.5.4 The dune environment, home of Charadriusalexandrinus(description and characteristics).
In the Marche region the Kentish plover 'Charadrius alexandrinus's considered as a breeding. In Senigallia it breeds in three different areas: Cesano, Cesanella and Marzocca . Since 2009 the monitoring of Kentish plover is regularly carried out along the coast of Senigallia and Montemarciano, where since 2011 there are some breeding pairs. In collaboration with local governments over the last four years some conservation strategies have been taken for the protection of the breeding population that also affect the dune habitat protection. In the study period there was an increase in the number of breeding pairs and a strong increase in the number of young fledged. The trend shows that we moved from 10-12 pairs in 2009 to 21-22 in 2012 and 2013. Compared to 2008 there was an increase of 72.4% of the nests found. In many cases along the south coast of Marzocca,
the roofs of bathing have been selected as a place of deposition. The dunes are deposits of sand that are formed when to establish a preferential direction of the wind which extends to accumulate the sand in regular deposits. They are formed whereas they are superficial deposits, as in the sandy deserts or along a sandy coast. In operation of their form different types of dune are known as, for instance, the barcanes. The dunes are sandy deposits few stable, whose form and whose position mute in continuation, especially in function of the direction and the strength of the wind. A dune can settle when it comes colonized from specialized plants, whose radical apparatus constitutes a network that has the tendency to consolidate as the sandy sediment. Among the various types of dunes, those coastlines not only represent environments of extraordinary ecological and landscape value but geologic since they represent a morphological barrier against the ingression harbor and an important reserve of sand able of power up the beaches during the erosive phases.
2.5.5 The dune environment, home of Smicromyrmeviduata(description and characteristics).
A dune is typically an accumulation of sandy sediment of wind origin, that is determined and shaped by the action of the winds , and therefore subject to continuous displacements and downsizing depending on the direction and strength of the wind. Sand deposition, accretion, and erosion within the coastal environment result in the development of a variety of dune morphologies; however, a general classification into primary and secondary dunes can be made. Primary dunes are composed of sand blown directly from the beach face, whereas secondary dunes develop following the subsequent modification of primary dunes.Other sand accumulations with morphology similar to that of the dunes are the ripple marks , known in Italian also as ripples or undulations.
In these areas we find a particular fauna, for exmple the Pimelia.
The Pimelia are Insects Coleoptera (Tenebrionidae) quite frequent on the coastal sandy beaches. They are species of about 1.5 cm in length, easily recognizable by their black and rounded appearance. The Pimelia are insects adapted to arid climates and desert environments thanks to the special protection provided by the leathery coating that prevents dehydration, the locomotion on the sand is facilitated by the presence of many bristles on the legs. The Pimelia belong to the class of animalia and to the genre of the insecta.The Pimelia feed mainly on debris, but during the breeding season they can also feed on other insects (adults, larvae and eggs) and therefore represent a potential predator of the caterpillars of the moth "Brithys crini pancratii". Pimelia are univoltine, with one generation per year.
After mating, the female digs a shallow hole and deposits a single egg, which closely resembles a grain of white rice. As the temperature rises above 50 °C the adult population dies off. During the winter the adults emerge. Several morphological adaptations allow Pimelia to survive in the desert.
2.5.6 The dune environment, home of Echinophoraspinosa (description and characteristics).
The fennel prickly shoreline is a plant of the Apiaceae family and is present everywhere in the coastal areas of the Mediterranean basin. It is a perennial herbaceous plant that grows on coastal dunes. So, the coastal dunes take on the shape of a beach, thickened thanks to the contributions of sandy sediments deriving in a dual manner from both the coastal currents and the waves. The upper part of a dune, called emerged or backshore beach, is subject to the removal of a pile of sandy material due to dominant winds, able to give light to new dunes, this time aeolic, whose base is given by the previous mounds sandy removed. This is how pioneer plants, such as Echinophora Spinosa, play a fundamental role, since it intervenes in the fixation and stabilization of sand in the dunes, which otherwise would disperse elsewhere due to winds and currents. The dune offers hospitality in periods of great heat and wind, it’s exposed to conditions of aridity and mobility of the substrate. The decomposition of algae on the latter (deposited by the waves during storms) nourishes the pioneer vegetation, but above all the halophyte plants (usually found on salty and alkaline soils, or in the presence of brackish waters) start colonization . These have roots so deep as to penetrate the groundwater, creating a network that consolidates the sandy sediment and that will be the basis of the future dune. Being hydrophobic plants, with little liquid dispersion, can only add nitrogen to the soil, favoring the colonization of other herbaceous species consisting of dry leaves with minimal pores to transpiration and hardly resistant to the conditions of the dune in which they are inserted. These new tenants add the humus to the soil like conifers, able to tolerate soil, but having a pH lower than 7 they make the soil slightly acidic. The coastal dunes, in addition to being an important ecosystem worthy of conservation, play an important role in the defense of the coast from the sea.
2.5.7 Cakilemaritimo: description and characteristics
The marine nasturtium is a species with a Mediterranean-Atlantic distribution that in Italy grows along all the coasts, pioneer on coastal sands, from here in ruderal environments subsides rich in nitrates, always on the coast. It is a plant with aperitif, digestive, carminative and diuretic properties. Thanks to the high content of vitamin C, iron and iodine was used as an antiscorbutic. In the kitchen the plant, still immature, can be eaten fresh in salad or cooked and from the seeds is obtained an oil similar to that obtained from mustard. It also has cosmetic uses: an extract obtained from the flowered tops has presumed anti-dandruff effects, while an infusion made from the leaves is used to cleanse oily skin. The name of the genus comes from the word 'kakeleh', which indicates the name of the plant in Arabic; the specific one alludes to the maritime habitat. Biological form: scaposa terofita. Flowering period: January-December. The ravastrello is an annual herbaceous plant. It is a bare, fatty beach plant with leaves that may or may not be divided or divided into two. Form mostly crowns ranging from purple to pink. The fruit is a double pod about 2 cm long and 5 wide. The upper member of the pod is pressed together. Mostly they are insects that help him in pollination. The floating fruits spread mainly on the water. Based on the fruits, two subspecies can be identified:
C. maritima Baltic subspecies: located along the coasts of the Baltic Sea, the lower part of the fruit has appendices bent backwards.
C. maritima maritima subspecies: it is widespread along the European coasts of the Atlantic and along the Mediterranean Sea, it is found in Germany and along the coasts of the North Sea, the lower part of the fruit has very short appendages.