Biodiversity

In dune systems, in general, because they constitute biologically rigorous environments, in which plant colonization is hampered by substrate mobility, wind, thermal variability, high soil permeability and saline gradient, only very specialized organisms are able to survive, facing challenges such as:

• Submersion in salt water;
• Burial risk;
• Difficulty obtaining fresh water;
• Attainment nutrients by plants;
• Large daily thermal amplitudes.

In different areas of the dune, different species can be found, which typically occur in those places and which have specific adaptations for their survival, with a zoning of species being perceptible.

The sand couch-grass (Elymus farctus) is the first species to settle in the process of forming a dune and acts as an obstacle to the wind that deposits the sediments it carries, forming the embryonic dune. In some places that are not very disturbed, a pre-dune colonized by European searocket (Cakile maritima) may appear.

In the case of this dune system, only a small area between Praia do Rodanho and Cabedelo has an embryonic dune, since the sharp erosion has led to its destruction, with a truncated dune cord, in which the frontal dune is also very threatened .

In the frontal dune, which typically appears just behind the embryonic dune, the dominant species is the European Marram Grass (Ammophila arenaria), also developing in this zone other species such as Silene littorea, the Euphorbia portlandica, the sea holly (Eryngium maritimum), the sea daffodil (Pancratium maritimum), among others.

Beyond the top of the Rodanho frontal dune, a drier and sheltered environment is formed - the interior dune system - where a much more complex plant community develops, with the development of annual and shrub plants, due to the greater stability of the sandy substrate. This plant community is dominated by the field wormwoods (Artemisia campestris) and the Italian strawflower (Helichrysum italicum), and there are also areas with Vulpia (Vulpia alopecurus), grey hair-grass (Corynephorus canescens), coastal medick (Medicago marina), "goivinho-da-praia" (Malcomia littorea), "ansarina" (Linaria polygalifolia) and blue pimpernel (Anagallis monelli), among others.

In the area furthest from the sea, there is an open forest system, where colonization by the maritime pine (Pinus pinaster) - wooded dunes predominates. However, colonization by exotic species, such as the long-leaved wattle (Acacia longifolia), has increased considerably.

Associated with the appearance of the first vascular flora, there is also a significant diversity of fauna, with insects and snails being the most frequent animals in this ecosystem. Some of the species that can be found in the Rodanho dunes are the spurge hawk-moth (Hyles euphorbiae), the Lusitanian sand grasshopper (Sphingonotus candidus subsp. Lusitanicus) and the white garden snail (Theba pisana).

There are also several species of reptiles and amphibians, such as the ocellated lizard (Timon lepidus) and toads (Epidalea calamita and Pelobates cultripes); mammals, such as the wood mouse (Apodemus sylvaticus), the weasel (Mustela nivalis), the red fox (Vulpes vulpes), the common genet (Genetta genetta), the european rabbit (Oryctolagus cuniculus) and the european hedgehog (Erinaceus europaeus); birds, such as the kentish plover (Charadrius alexandrinus), among other biological groups.

Many animals have characteristics that allow them to survive in this environment, such as colors and shapes that allow them to be confused with sand or leaves - camouflage - or flashy colors that warn of their bad taste and toxicity and ward off potential predators - aposematism.

Discover some of the species that can be found in this location, under the "Multimedia" tab.