NATURE

Under the protection of the Parc de la Serralada Litoral (Coastal Range Park), the valley of the Mogent River and the Camino Real, or Royal Road, La Roca del Vallès also enjoys a pleasant and varied natural and scenic environment and with architectural sites that are packed with history which have marked the character and evolution of the territory over the centuries. This unique natural environment also provides residents and visitors with a great variety of outings by bicycle or for walks along rural roads and the course of the Mogent river, a very healthy way to get to know the surroundings of the municipality.

Discover

Vegetation

The area where the itinerary runs would correspond mostly to a potential vegetation (CLIMAX) that we know as “holm oak with laurustinus” (Quercetum illicis galloprovinciale, in scientific terms). This vegetation is altered by two very important factors. On the one hand, by the action of man, with the abusive logging of oaks, it has favoured the penetration of pine trees (several species), all of which need more sunlight than the oak itself. On the other hand, the orientation of the massif, together with frequent fogs, endows this sector of the massif with a level of humidity and freshness that favours the presence of more sub-Mediterranean or mountain species, such as oaks, abundant mosses and lichens The undergrowth also demonstrates this combination of factors, in that laurustinus, heathers, and strawberry trees, along with other shrubs all coexist, replacing or alternating the soil or the level of degradation that the forest has suffered, depending on the light.

Reaching the hill and already along the SP (short path), the predominance of pines is overwhelming, accompanied, as if it could not be otherwise, by strawberry trees and heather. Stone pine, Aleppo pine, Maritime pine and California pine coexist in an apparently disorderly and chaotic way. This meeting point of paths offers visitors excellent views of the Vallès region. Going down towards the stream, some specimens of Austrian pine will appear and finally we will enter the riparian woodland, an authentic ambassador of the Euro-Siberian plant communities. Its humidity and freshness will invite the presence of deciduous trees such as hazel and alder, accompanied by plants such as ferns, mare’s tail, carex, cane, etc., all indicating that we are in another natural environment typical of the banks of Mediterranean water courses.

Fauna

Talking about the animals that occupy a territory is always complex, due to the difficulty of observation that it entails in many cases, especially in regard to vertebrates. So, in large part, we have to make a “leap of faith” and remember that we’ll have to rely on the traces, footprints, food remains or other indirect data if we want to have any idea, for example, of what kind of mammals inhabit a specific zone, unless we have a bit of luck and surprise a distracted boar or some curious fox! The Fauna that one hopes to find in this area of ​​the proposed route is typical of the Mediterranean region. So in the areas of scrubland and at the edges of the trail, in regard to mammals, we will find: rabbits, foxes, badgers and wild boars (omnipresent in all environments along the trail). As for the birds, partridges, warblers, greenfinches, serins, finches and goldfinches will show a certain preference for these areas of shrub vegetation with isolated trees that some species will use as a lookout to mark their territories.

In more wooded areas, we can hear robins, tits, jays, wood pigeons, green woodpeckers, blackbirds, and at night, the intriguing hoot of tawny owls. Needless to say, in areas where pine trees are common, we can see the presence of pine cones eaten by squirrels or forest mice. Regarding reptiles, they will be more common in dry and rocky areas where we can find: common and long-tailed lizards, ladder snakes or the splendid green or Montpellier snake. These snakes will be potential prey for one of the most beautiful eagles of our Mediterranean sky: the short-toed snake eagle, a specialist in catching reptiles, which visits us each spring from the African continent.

In the riverbank area we can see (or more easily hear) Iberian green frogs, midwife toads, the common and natterjack toads, salamanders, etc. All these amphibians will make their homes in the humidity and freshness they will only find in these spots. Wherever the water is still enough, we can observe some swimming water snakes, looking for any of the aforementioned amphibians. It’s fair to say that near the riparian areas, among the brush and scrubs, we can hear the splendid song of the nightingale, but only when the good weather comes that is. We can also see the beautiful oriole, a summer bird, crossing the green canopies of the alders and poplars, as well as the nightingale, also from African lands, which with its exotic song and striking colours evokes the distant tropical lands where it comes from.

The arthropods (insects, spiders and millipedes, among many others) found here in any plant community, including pine trees, are extraordinarily numerous. Although the number of flowers is relatively scarce within the pine forests, the insects are particularly abundant, not only as a result of their mobility (beetles, butterflies, flies, mosquitoes, bees, wasps, ants, etc.), but because many of the larvae are vegetarian or parasitic, so adults can search for suitable places where they can lay their eggs. On the other hand, the huge number of species of arthropods and the lack of knowledge regarding most of these species by the general public makes it impossible to list them. In spite of this, we will emphasise some examples that are well known or easy to spot. Throughout the route, we can see some pockets of pine processionary caterpillar colonies on the pine trees. This is a well-known species because of the problems caused to people due to the allergic reactions that the caterpillar hairs produce. During the spring, we can find termites in the bases of the pine trees and during the summer we can hear the songs of the cicadas. We can also see various species of butterflies, bees and wasps, and even beetles, flitting around the flowers. Nor can we forget the scolytinae, bark beetles that bore through wood and which leave their tunnel marks on the underside of the bark. As for the spiders, their cobwebs are pretty showy; several families build them among the branches of the heather and other shrubs, making longer clumps which are more or less concave or convex in shape. The list of arthropods would be endless, so we recommend walkers to take guides along the way to help them with the task of identification.

Geology

The territory through which the trail runs is comprised of granite, as is, in fact, most of the Céllecs massif and the coastal range as a whole. This composition will determine the acidic properties of the soil and the characteristics of the terrain.

Indeed, the formations are predominantly soft, although you can find some cliffs resulting from fractures or joints where the greyish granite that is typical of the area emerges. The result of the erosive action of water and wind and, to a lesser degree, changes in temperature, have formed the “boulders” or large rounded blocks. In addition to erosion, there are often small holes, or “alveoli”, and sometimes even holes of considerable diameter carved into them. Some of them are well-known along the Prehistoric Trail, having been the object of human activity since ancient times.

Also very common, in the low places and paths, is the presence of granite sand. This permeable sand, the result of the degradation of the feldspars in granite, forms important deposits, including beaches, in the neighbouring Maresme region. Also equally noteworthy are the gullys that we will find on the sloped path, which aside from making it difficult for us to walk, will expose outcrops of levees and veins of harder materials, such as aplite and pegmatite, crossing the granitic batholiths which form the massif. It is worth noting that these mineral materials have been mined, as is evident with the quarry at the beginning and end of the trail.

Human Activities

Mineral mining in granite quarries is one of the traditional economic activities of people in the massif. This has not always taken the necessary respect for the environment into account, and has had a strong impact on the landscape of the mountain range.

Another economic activity linked to the forests we are passing through, is the production of charcoal. This practice, now obsolete due to new energy sources, gave rise to an entire “culture” around the men who practised it, and who often had to spend months living in the forest with a primary subsistence economy with ancestral roots. Of course this forestry culture has been forgotten or is preserved in a purely anecdotal way. Finally, it is worth mentioning economic activity linked to the forest that is still going strong, such as plantations or forest cultivation. For example, the Maritime pine of Ca l’Argent. This is an economic activity that still provides economic returns to the massif, but which must be carried out with a lot of common sense and knowledge about the mechanisms of forest dynamics in order to prevent an excessive impact on the ecology of the massif (remember that it is currently under the protection of the PEIN – Plan for Spaces of Natural Interest), so that the work of logging and respect for the forests and their rich flora and fauna can coexist harmoniously.

Arbres i arbredes monumentals

These two elements are very common throughout the municipality and the areas of interest have been catalogued with 23 elements in the Catalogue of Monumental Trees and Groves of the district. In addition, two ponds and a wildlife refuge have been inventoried in the area of Can Sant Pere and the Parc de la Serralada Litoral (Coastal Range Park), as it is protected and considered by law as an area of special natural interest.

On the other hand, La Roca has different unique botanical specimens, most of them corresponding to the trees and groves of the district, totalling 73 elements. The rest of the elements of natural interest are comprised of 5 elements, 4 of which correspond to flowers (Carex Grioletti, Teesdalia Coronopifolia, Venetian Parsley, Orphrys Bertolonii Moretti subsp. Cataunica, Autumn Orchid) and the fifth to wildlife. The Marbled Newt, a very rare amphibian has been documented in the part of the Coastal Range Park that is located within the municipality.

You can see the file on the natural elements of the municipality using this link: http://patrimonicultural.diba.cat/index.php?codi_ine=08181

The trails

La Brolla Trail

One of the most important assets of the municipality is the natural environment, noted for its good state of conservation and its size.

This is one of the proposed itineraries for enjoying the landscape and seeing some of the heritage of La Roca del Vallès. It is ideal for fans of birdwatching.

The attractions that are found in this section are: from La Roca del Vallès to Santa Agnès de Malanyanes and back to La Roca:

  • Town Hall
  • Castle
  • Malanyanes Hermitage
  • Duck Pond (Bassa dels Ànecs)
  • Grey Heron

Santa Agnès de Malanyanes

One of the most important assets of the municipality is the natural environment, noted for its good state of conservation and its size.

This is one of the proposed itineraries for enjoying the landscape and seeing some of the heritage of La Roca del Vallès. It is ideal for fans of birdwatching.

The attractions that are found in this section are: from La Roca del Vallès to Santa Agnès de Malanyanes and back to La Roca:

  • Town Hall
  • Castle
  • Malanyanes Hermitage
  • Duck Pond (Bassa dels Ànecs)
  • Grey Heron