What is a dune?

A dune is a set of sand that forms a small hill, but it is also an ecosystem in itself. What does this mean? It means a group of animals and plants that live together in the same habitat. Our dunes are an ecosystem on the beach and, in our case, also very close to buildings where people live.

In the dunes we find animals and plants that are autochthonous, that is, they are only going to be found here and nowhere else. These plants include the thistle, which is very adapted to living in the dunes.

Next I would like to explain the different stages of dune construction so that when you visit the Artola Dunes or any of the other dunes that make up our Ecological Reserve, you can classify and recognize this characteristic ecosystem.

Dunes develop in three phases:

• First is the embryonic dune or pioneer dune; these dunes move a lot. The action of the wind and the sea cause them to be in constant movement. The sand that builds them is changing shape. In these dunes, the plants have to have very strong roots to be able to get established, they will have very characteristic roots that, by holding the sand in place, will give the dune its shape and consistency. There are few species that manage to live in these highly mobile dunes, which is why it is very important to conserve these plant species.
• The next phase is the primary dune or moving dune; in these dunes the plants are going to be larger, they will form thickets, they will have more solid structures and we can already find some with woody stems. Some of these bushes are, for example, the bitter chamomile and the sea horn. Both are well adapted to the dunes as they have structures that protect them from the sun and from insects that can cause damage. Likewise, they withstand the salinity of the environment very well. Because of this, in this dune we will find a greater accumulation of water, by condensation, which will allow the plants to grow more.
• We now go on to the third and final phase, which is the secondary dune or fixed dune. Here we find plants which are stronger and more solid. They already have well-developed woody stems and get to be a lot bigger, such as mastic or pine. We can also find larger animals, such as rabbits or a very special one, the common chameleon, which is currently in danger of extinction. ProDunas Marbella has fought to reintroduce this species to its habitat and we now can find some specimens living in trees such as mastic or wild olive.

Importance of the Dunes.

The dunes are a reserve of sand for the natural regeneration of the beaches. The prevailing winds in coastal areas have a natural sand movement circuit, inland in some cases and towards the beach in others.

They are elements of the landscape of enormous ecological value. They establish a natural transition between the coastline and the hinterland.

They have a wealth of fauna and vegetation exclusive to these transit areas between salty and semi-fresh or fresh waters. They distinguish the coasts of our country, where endemic species protected by the Habitat Directive of the European Union (EU) grow.

For this reason, if the dune chains are altered or eliminated, the beaches lose their natural nourishment and start, generally speaking, on a downward spiral of progressive loss of sand. This has to be replaced by artificial means, by the hand of the human being. If the shape of the dunes is changed, or if they disappear, the beaches would disappear also. Only constant maintenance would create artificial, beaches which would have to be maintained at a huge economic cost and it would be a never ending task. In other words: no dunes, no beaches.

Dune Conservation.

ProDunas is an environmental association in Marbella with almost 250 members. It has been fighting since 2004 to protect the dunes, their native species and the ecosystem in general.

The Association takes care of the conservation of this Ecological Nature Reserve and, consequently, of its dunes, carrying out different activities such as:

• Protection of the dunes by installing footbridges, fences, perimeter posts, etc.
• Cleaning up the environment, removing rubbish and providing the area with litter bins and containers.
• Improving vegetation. ProDunas Marbella also carries out important work to eradicate invasive species. Because of the proximity of the buildings where people live to this emblematic ecosystem, many of the seeds of garden plants get dispersed by the wind and birds and are dropped on the dunes. These species evolve in the dunes as invasive species, taking away space and nutrition from the native plants that belong there. For this reason, the Association organises volunteer days where we eradicate these species, uprooting the specimens to prevent them from spreading.
• Repopulation with native species and pruning of bushes and trees.
• Improvement of the geomorphology of the dunes by installing sand collectors or correcting compression damage caused by the passage of many feet.
• Provision of various elements for public use such as information panels or warning signs.
• Provision of support infrastructure such as parking areas outside the dune environments.

Since 2013 we have also been offering dune sponsorship for schoolchildren and 14 schools have joined in. Apart from this important program, excursions and visits are carried out with the schools to explain to the children and young adults what the dune environment is and how we can protect it.

We encourage everyone who wants to participate in the conservation and maintenance of this Marbella treasure, to get in touch with the Association through the ProDunas Marbella web page or by Facebook, where you can also follow up all our activities and work.

Estefanía Espejo González
Marine Biologist ProDunas Marbella