SIERRA NEVADA: NATURAL AND NATIONAL PARKS

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The beautiful Lecrin Valley region of Granada province is situated in the foothills of the majestic mountainous massif known as the Sierra Nevada, some thirty kilometres from the city of Granada in the south-western region. It has a privileged location which acts like a narrow natural corridor, bringing together other neighbouring and mutually distinctive regions such as Vega del Río Genil, el Temple, La Alpujarra and the Costa Tropical. Owing to its geographical setting it marks the separation between the Sierra Nevada, which rises from the municipality of Padul and other important mountain reliefs, which formerly formed part of it but that have become separated due to fluvial action and various tectonic episodes which took place in this area several thousand years ago. These reliefs are the Sierra de las Albuñuelas and the Sierra de los Guájares which border the valley to the west and to the south. Lecrin Valley also boasts Padul Lake, with its many aquifers responsible for the valley’s biological richness. Consequently, this wetland area is considered to be one of the most important of the peninsula’s south-east region.

There are many aspects of the Sierra Nevada and the Lecrin Valley which could be studied, but the aim of this article is to explain its physical environment to readers, since this is the origin of its enormous natural richness. We shall deepen our understanding of the geological and morphological characteristics of the terrain, of the animal and plant diversity within its ecosystems, and we shall travel through each of the most evocative corners which this countryside harbours. The greatest part of this environmental treasure is offered by the area which is located at the foot of the Sierra Nevada, and so in the following pages I shall describe in detail everything related to this massif. The altitude of the Sierra Nevada and its low latitude determine its natural conditions: a climate of contrasts, and a diversity of flora and fauna which gives rise to a large variety of plant and animal species particular to this region and which form a significant population; it is the most representative of the Mediterranean High Mountain Ecosystems. It offers more than 1700 different plants, hosting 64 examples of endemisms and 176 classes exclusive to the Iberian Peninsula. As regards the fauna, it hosts 150 endemic species of insect, 90 of which are aquatic, as well as others which are highly representative. We are in the presence of a natural site monitored and controlled by various institutions and national and international organisations, which have made it worthy of significant recognition because of its richness and its scenic variety, and because of the fragility and vulnerability of its geosystems:

As a consequence of these declarations, the National Park is subject to higher levels of protection. Its territory comprises the nucleus of the Sierra Nevada and reaches the high summits. Around this the Natural Park is situated, bordering it at lower altitudes in what is called the medium and low mountains.

GEOLOGICAL HISTORY OF THE SIERRA NEVADA AND THE LECRIN VALLEY

Contrary to what you may think, the Sierra Nevada has not existed forever and in geological terms, it is a young mountain. Before its birth it was submerged within a shallow sea, the predecessor to the current Mediterranean; diverse substances were washed towards this area and progressively deposited in different layers (called “strata” by geologists). This occurred more than a thousand million years ago in the first geological era, during the Precambrian period.

In the Tertiary Period, some 30 or 40 million years ago, an important geological phenomenon took place, the Alpine Orogenesis, which within this area brought about a process of plication in response to the approach and subsequent collision of the African Tectonic Plate against the Central Iberian Massif, situated on the European Tectonic Plate. It was at this point that the Sierra Nevada emerged, rising up due to the interplay of compression-distension movements (in a north-north-westerly/south-south-easterly direction) and the opposing pressures between the two plates. But its current mass and altitude are more recent, achieved barely 11 million years ago, during the Superior Miocene (Tertiary) and specifically on the Tortonian stratum. All of these processes continue today. The young age of the sierra may be explained by the fact that its foundations are not yet stabilised, as is also the case in all mountain systems of the Mediterranean basin. It is the same age as the Alps or the Himalayas. The best proof of this is the instability which it registers: recent formations of ravines and river furrows, a profusion of fractures and faults which affect buildings, some particularly pronounced, earth tremors, and so on. All of this is a result of what is called the post-alpine geotectonic. The basal sediments which were deposited at the bottom of the primitive sea underwent intense transformation (which we call metamorphism) and deformation; this was a consequence of their burial, subsequent elevation and appearance on the surface to form the currently observable mountain chain. This deformation is reflected in the characteristic steep ground, folds and fractures which show us their different rock types. The sediments mentioned above gave way to a succession of layers, which geologists call Sliding Strata, including rocks of different natures and ages. As a whole, three complexes or structural units can be distinguished, which (from deepest to most superficial) are: Nevado-Filábride, Alpujárride and Maláguide.

The rocks of the high peaks are grouped under the geological designation of Nevado-Filábride Complex. They are the oldest, their age perhaps Palezoic or even Precambrian – greater than 250 million years old and on occasion perhaps even more than a thousand million years old. Bordering the nucleus of the sierra another band of rocks appears, called the Alpujárride Complex, also more than 200 million years old and distributed in the adjoining ridges within the area of middle and low mountain. At this time, around the Superior Triassic, movements occurred in the marine sedimentary basin which was at the foot of the mountain; there is evidence of various highly significant interplays of faults. Finally, the outermost band of the Sierra Nevada corresponds to much younger sedimentary materials which were deposited in the last 15 million years during the Middle Miocene, as products resulting from the erosion of the sierra, at the bottom of the small marine basins which surrounded this incipient relief rising from the bottom of the Mediterranean sea. The definitive emersion of the region caused the sea to retreat slowly to its current position, and the materials resulting from erosion appeared at its feet, in the basin of the same rivers which today have their source in the region. During this period a series of tectonic episodes of relative importance took place and it was at this time that the Lecrin Valley was formed – not a valley in reality, but rather a typical tectonic basin caused by former subsidence between two fracture lines. Erosion sculpts the landscape and simultaneously fills depressions in with sediments of different and alternating compositions, the majority belonging to shallow marine facies with abundant fauna, according to the remains discovered in several zones such as the reefs of Albuñuelas and Murchas. This tectonic basin is the one which dictated the morphology of this district, becoming separated from the depression of the River Genil by the threshold of el Suspiro del Moro, which moreover demarcates the watershed. The rivers which are situated to the north of el Suspiro del Moro flow out into the Atlantic Ocean, and those to the south into the Mediterranean. Small depressions are fashioned within the basin: that of Padul-Dúrcal, and that of the confluence of the rivers Dúrcal-Torrente-Albuñuelas.

Entering the Quaternary Period, specifically in the Pliocene Epoch, the individualisation of the Sierra Nevada becomes notable, delimited by the alignment of a series of valleys to the north and to the south which in turn flank lesser sierras in their environs. These geological processes continue throughout this period, as ancient reliefs progressively rise up and on whose Miocene covers the current hydrographic network runs. Erosion and sedimentation broke the valley down into a series of lesser units with their own characteristics and identity. The Padul Depression (situated above 650 metres) is separated from the Dúrcal-Nigüelas Basin by the materials deposited by the Dúrcal river on leaving the sierra. It was a completely enclosed hollow where the waters were held in, thus forming Padul Lake where a process of in-filling takes place, but this time with lacustrine facies. The proof of this is the bog which appears in its environs. The valleys of the rivers Torrente and Izbor and the Melegís and Albuñuelas Depression, which correspond to alluvial plains and debris cones, were subsequently hollowed out, giving rise to terraced shelves at lower altitudes. The basin is delimited by normal fault lines, such as that of Padul-Dúrcal-Nigüelas, which is large in longitude and where alluvial fans are abundant; this was declared a Natural Monument.

Evidence exists of Quaternary glacial ages, in spite of the sierra’s low latitude, because of the pronounced altitude which was attained; this gave rise to interesting glacierism phenomena, a reflection of which is the ensemble of lakes near its peaks. These occurred at least 10,000 years ago, during the last glaciationthe Würm – in which glacial systems evolved which fed spits and rivers of snow which have now disappeared. Further evidence of these phenomena are the cirques and the polished glaciers, the palisade systems and the moraines. As these periods of glaciation came to an end, the basin and its rivers were canalised in their current position, leaving fluvial terraces suspended along some stretches of these river-beds. Through the years, locals have taken advantage of these terraces to grow various crops.

ALONG THE HIGH SUMMITS: NATIONAL PARK

Broadly speaking, the highest stretches of the sierra are to be found within the limits of the National Park. The Lecrin Valley occupies the westernmost sector within the park’s boundaries, there are three municipal areas on its territory: Dúrcal, Nigüelas and Lecrin. It rises from approximately 1900-2000 metres upwards until its highest peak is reached, the immense Cerro del Caballo at 3015 metres above sea level, rising onwards to the Picón de Jérez situated at 3098 metres. The Cerro del Caballo is a spur with numerous crests, which marks the divide between the rivers Dúrcal-Torrente and that of Lanjarón. It is a vantage point which towers above surprising panoramas, which include, if we look eastwards, high points in the province of Almería and the most important peaks in the penibetic massif: el Mulhacén, el Veleta, la Alcazaba, and so on. Looking in the other direction we can observe the sierras of Guájares, Almijara and Tejeda as well as the whole of Granada’s rich lowland areas.

As far as geomorphology is concerned, sharper and rougher shapes are to be observed in the higher areas, but as we drop down the relief softens and offers us a highly contrasted variety of scenery. The low ridges and hillsides, vast and not particularly pronounced, form the stretches of sloping ground which link the high summits with the depths of the ravines, shaping the areas of water partition and fashioning the course of the collector furrows. They frequently appear carpeted with deposits of clasts which give them concave profiles. In these gently sloping areas, channels drop down alongside meadows where the fissures of the hydrographic network barely stand out, with just a few steep cliffs and crests where glacierism took place. In the places where the glaciers formerly existed, there is now an ensemble of small lakes, some of which are surrounded by meadows (called borreguiles) which provide excellent fodder for cattle in the high mountains. The best-known lakes which we find in the Cerro del Caballo are those which are situated in the high valley of the River Lanjarón between 2800 and 3000 metres. These are Lake Baró, also known as Lake Lanjarón because it is the place where this peculiar river rises, Lake Bolaños, Lake Cuadrada (or “Lake de los Puerta”), Lake Caballo, and Lake Nájera, which is accompanied by the small pool of the Lavadero de la Reina, next to the Tajo de los Machos. Near the source of the river Dúrcal there is another small lake called la Mula. Not all of these lakes are permanent, since some will disappear in drought years or during the summer months. In winter months, they are covered by a thick layer of ice which can be walked upon just like solid ground.

These former glacial valleys have been commandeered by today’s river network in a clear example of a relief redolent of Alpine models, squeezing through the furrows and ravines. Two of the valley’s most important rivers rise in the Cerro del Caballo; I refer to the River Torrente, whose source is located in the Loma del Caballo (belonging to the Nigüelas mountain range), and the river Dúrcal, which rises at a spot known as los Prados del Nacimiento in the Dúrcal mountain range. Numerous streams which intermittently cross through the ravines of these reliefs join up with these water courses. Although these rivers rise in areas of the high mountain, nourished by the winter snow and rainfall through the rest of the year (which stems from the influence of the Mediterranean climate), they are characterised by suffering a significant low water level during the summer months and by their tendency to torrential and violent flooding. In some places, the snow which has fallen during the winter lingers for long periods of time, above all in the places most exposed to northerly winds and protected from the sun – this increases the reserves of water in our aquifers and springs.

The lithology of the high summits and adjoining hillocks is fashioned in the Nevado-Filábride Complex, mentioned above, and is defined by its formation of a vault where crystalline metamorphic rocks predominate which are constituted principally from graphite micaschists. These are dark-coloured siliceous rocks with a slate-like appearance which have a characteristic “slab” dividing them into plates which are more or less irregular, but well-defined. They are frequently cut through by veins of quartzite of bright white or yellowish colours, by siderite and by iron oxides. The crests and steep cliffs which can be seen at the summit and nearby are usually formed by quartz schists, which offer greater resistance to erosion. To a lesser degree, green-coloured rocks are also to be found which are called serpentinites, eclogites and amphibolites. They are located in the Loma de los Tres Mojones, near the spot known as la Rinconada de Nigüelas. A quarry was formerly worked in this area, although it has now fallen into disuse, since this type of rock was at times used as an ornamental stone, for the manufacture of agglomerates, for obtaining asbestos and talcum powder and so on. In more specific local areas, rocks appear which are closely related to magmatic processes – known as gneisses - which have a very particular ribboned appearance characterised by light and dark colours. All of these materials have a characteristic in common - their impermeability - which means that water accumulates in layers and gives rise to springs and subterranean streams at a very high altitude. These circulate slowly and naturally through the ground towards the source, thereby avoiding rapid external loss due to evaporation. The waters of this part of the massif are generally of excellent quality, both the surface water resulting from the melting of ice and also the subterranean sources, the latter on occasions containing minerals.

The prevailing climate is Mediterranean, specifically of the crioro-mediterranean stratum, which is characterised by the brevity of the vegetative period, the almost constant presence of snow, daily frosts and a scarcity of rainfall in summer – all of which limit the evolution of living beings. These conditions directly influence the evolution of plant cover, leading to siliceous vegetation – so-called because of the composition of the earth, rich in silica and varied according to different areas. The fauna is also affected, particularly warm-blooded vertebrates, whilst the invertebrate group shows a certain diversity since it reduces biological activity to the minimum. This environmental diversity has allowed the evolution of numerous ecosystems which are associated with particular conditions of ground, humidity and temperature. According to the area of mountain range where we are, we will find one or other ecosystem, depending to a large extent on the considerable altitude which is what causes these extremes of climate. This implies very severe limits for soil formation and the ability of plants to take root, preventing the evolution of tree species. The predominant landscapes are gentle and without projections, which contrast with the peaks and other rocky elements, appearing almost completely bereft of vegetation, with just a few lichens adopted to the climatic rigours. These have a reddish hue, which tends to cover the ground, although the predominant colours are those of the rocks ranging from light grey to grey-black. There is a cold and arid environment close to the high-altitude tundra, characterised by the predominance of exposed rock, substratum or stony ground. The vegetation and the fauna which live in this part of the Sierra Nevada are of enormous interest from an ecological and scientific standpoint, since life here is only possible with very particular biological adaptations which have been achieved by the organisms through a progressive evolution of thousands of years. It shows us a botanical and animal diversity which is also a direct consequence of the geological substrata already mentioned, as well as of the isolation with respect to the other systems which surround it. For this reason, we find many species which are exclusive to these mountain environs, the majority of which are very sensitive to the actions of man and cattle. We are therefore talking about ecosystems of huge environmental importance which, because of their extreme fragility, must be preserved in their totality. We shall delve into each one of them in order to discover their natural values:

The first to be studied are the cold, dry pastures of the high mountain which evolve above 2800 metres in altitude, distributed amongst the slopes near to the sources of the rivers Dúrcal, Torrente and Lanjarón. Here are herbaceous communities of meagre reach and coverage, these being the only ones capable of withstanding the environmental difficulties, implanted in areas where the ground is a little deeper. This is a pasture where perennial grasses and small shrubs predominate which are scarcely perceptible in the general landscape, completely adapted to the cold and the dryness of the high mountain. Flora abounds which is exclusive to these locations, such as mountain camomile, the thistle tribulus terrestris, tarragon, the Sierra Nevada violet, hogweed, dandelions, and the beautiful purple Hormathophylla. Alongside these, flora evolves of the boreo-alpine type such as Alpine Gentian, the mountain poppy or the Alpine Skullcap. On rocky ground and on rocks themselves, there are abundant examples of the crucifer shrub (hormathophylla spinosa); by contrast, in deeper and moister ground due to the long permanence of the snowfields, we frequently come across the black bilberry (vaccinium myrtillus) and small scattered flowers such as the diminutive mucizonia sedoides and linaria aeruginea. Mineral-rich soil is chosen by species such as erodium cheilantifolium, arenaria pungens clemente and the common stork’s bill, amongst others. On scree, the most characteristic elements are linaria glaciales, the grass holcus caespitosus, the rare arenaria nevadensis, the striking crepis oporinoides, together with some of the species mentioned earlier. Craggy ground is also important, since here species adapted to living in rock fissures appear, such as the endemic perennial pepperweed (lepidium latifolium), holcus caespitosus, draba dubia, the ferns asplenium viride and polystichum lonchitas, the beautiful buttercup and the unique “little bell of the Sierra Nevada”. The fauna boasts a high diversity of species and is characterised by the limited number of individuals due to atmospheric pressure, extreme conditions and low plant productivity. Within the community of invertebrate animals, insects stand out because of their diversity, amongst which the most notable are the emblematic butterfly of this mountain range, the apolo, characterised by the presence of circular yellow-orange patches. As for the vertebrate group, the species which live in the highest reaches of the mountain range are the Spanish ibex, the Alpine accentor, the golden eagle, the snow vole and the Iberian small lizard. At lower altitudes, under 3000 metres, small numbers of individuals appear: the tawny pipit, the northern wheatear, the common vole, the red-billed chough, and the eye-catching black redstart.

Another of the ecosystems which we find is that which evolves in diverse areas situated above 2000 metres in altitude, characterised by the permanent presence of water, such as lake zones. The constant availability of water sustains a significant level of productivity in the lakeside vegetation and this ecosystem corresponds to various types of moist pastures which are covered by snow for a large part of the year. It is to be found above all around the group of lakes mentioned earlier, located in the Cerro del Caballo. In less moist zones, species abound such as edelweiss (the “star of the snows”), comfrey, Armenia splendens, Agrostis nevadensis, lotus (“little horn”) or papo. In zones with constant humidity throughout the summer, a denser pasture appears where several species stand out: matgrass (nardus stricta), pinguicula dertosensis, the meadow buttercup, campanilla, the hispanic luzula and festuca trichophylla, black bilberry and the buttercup ranunculus acetosellifolius. In some places, where there is a constant quantity of puddles and stagnant water until the autumn, marshy ground takes hold where the following species appear: wild poppies, the buttercup ranunculus augustifolius or the grass festuca frígida. In springs and rising water courses, communities of moss come to dominate, giving rise to striking “pillows” of a light green colour. If the land is fertilised by cattle, such interesting species as the silverdust and aconitum burnati appear. Within the interior of the lakes we find a plant presence which is not particularly diverse, but which sustains a food chain in which reduced populations of tiny algae serve as food for small copepode invertebrates, which are small water fleas or rotíferos. Fauna is more abundant than in the pastures and animals are frequently seen during the spring and summer when the ice begins to melt. Insects are more numerous, including unique examples of endemisms such as some predatory and herbivorous beetles, the earwig or the tetrix bipunctata grasshopper. Within the bird population, noteworthy are the red-billed chough, the rock bunting, the common partridge and the northern wheatear; amongst the migratory species which settle in this area during the autumn are the ring ouzel and the linnet. The most frequently encountered mammals are the common vole, the fox and the Spanish Ibex.

Underneath the preceding ecosystems we find the domain of the juniper-laburnum field, which is situated in an altitude range between 1800 metres and 3000 metres, occupying the largest part of the area. It extends over numerous points of the Sierra de Dúrcal and of Nigüelas, including the Raya de la Dehesa, la Solana, la Loma de los Tres Mojones, Los Hoyos. The action of snow limits life in these areas; for this reason, the species in this area tend to have special “padding” in response to the austere conditions. Here we see the juniper and the savin (juniperus sabina), laburnum such as gentista versicolor and cystitus galianoi, and in more specific zones the pink and blue larburnum. This latter sometimes appears to be in decline because of various factors, including the activity of man and shepherding. As a product of this decline, a mixture of quite complex communities is generated. In harsh pastures, the tor grass brachypodium pinnatum dominates, as well as diverse grasses which are accompanied by striking flora such as the jurinea humilis, the papo, the dandelion, the mountain rue, the ragwort, and so on. Also to be found are thyme, the mountain zahareña, the “shepherd’s cushion” arenaria pungens clemente, the laburnum astragalus sempervirens, the woundwort, the “mountain tea” satureja alpina, amongst others. Noteworthy in the semi-permanent rocky ground is the presence of the common foxglove, the plumbago europaea, the orchard grass dactylus glomerata, the sorrel rumex lunaria, crepis oporinoides, diverse types of thistle, the flannel plant, the horehound or wormwood. On rock faces and rocky outcrops, species establish themselves such as valerian, the strawflower, cat’s claw, draba hispanica, and striking communities of lichens. The fauna is much richer than in the high peaks, as the same species are present alongside many new varieties due to the considerable growth of bush. In the case of the invertebrates group, we find numerous examples of endemism which present notable morphological and physiological adaptations to these adverse ecological conditions. Noteworthy are various types of grasshoppers, butterflies, ants and beetles, and also the polistes biglumis wasp, within an exceptionally long list of species. Within the bird population we might underline the presence of the eagle owl, rock thrush, ring ouzel, linnet, crested lark and the common kestrel. These areas are also home to the wood mouse and its predators: the weasel and Lataste’s viper.

DESCENT TO THE MIDDLE MOUNTAIN: NATURAL PARK AND OTHER AREAS

The area of mountain which I shall now describe covers the part of the Lecrin Valley which is located within the Natural Park of the Sierra Nevada, taking in four of its municipalities which cover an area of 11,990 hectares. These municipalities are Padul, Dúrcal, Nigüelas and Lecrin. Moreover, the zones of the remaining municipal districts which present the characteristics of this section of mountain are also included, such as the sierras of Albuñuelas and Guájares. This constitutes the perimetric boundary which borders the high mountain in the periphery of the limits of the National Park, situated at more or less 1900-2000 metres in altitude and it is distributed through these slopes which descend until they enter into contact with cultivated areas located at a lower altitude, around 800-1000 metres.

The lithology of this zone is shaped in the Alpujárride Complex, forming a band of carbonated rocks which borders the summit vault of micaschists, giving rise to the most characteristic reliefs of the middle and high mountain. It is mainly composed of two types of rock which are easily recognisable in the landscape. The most abundant is the ensemble of limestone and dolomite, composed of carbonates of sodium and magnesium in whitish and greyish colours which at times have the appearance of having been crushed due to intense tectonic activity. These constitute the essential element of the Cerro de Loma and Cerro del Manar and of the sierras of la Silleta and el Escopetar in the municipality of Padul. In the area of Dúrcal it spreads out through Las Buitreras, La Chaja, Peñón de Granada, Peña Gallo, and El Zahor. This type of material is used above all in the construction industry. It is obtained for the manufacture of dry goods and asphalt fillings, and for lime. Consequently, in this part of the district a number of sand extracting industries are located, above all those which are to be found in the mountainous area of Manar and in el Zahor. Another type of rock associated with those preceding is the filite known in the district as “launa”. This is partly transformed clay composed of mica and quartz, in very vivid colours, bluish or brilliant greys. This part of the sierra offers us a characteristic relief hollowed out by erosion, in rough and broken shapes, with plentiful watercourses in the sandstone and gullies which flow with high erosive power (leading to localised instances of desertification). The geomorphology of the zone is so abrupt and so varied that it gives the landscape a special charm, making it exceedingly attractive and interesting because of its scenic panoramas. One of the most representative enclaves is the so-called Barranco de la Rambla, which stretches from Collado de los Voladores to Peña Gallo, an immense spit of sand and stones which flows like a river when a storm breaks out, testifying to the high levels of erosive power to which these areas are subject.

With regard to the climate, from its starting point at high altitudes this area presents a rich variety of layers within the Mediterranean model which change in keeping with the principle that temperature rises as altitude drops. As all of this area is shielded from the cold northern winds, there is a certain mildness to the temperatures, leading to a flow of biological activity. In this zone a series of ecosystems evolves which includes a large quantity of habitats, amongst which tree growth is of particular note. This is an environment where forests dominate, although large surface areas have been subject (for diverse reasons) to different processes of degradation and are made up of bush and scrub types of vegetation. Man has wished to promote the growth of woodland, for which reason in some areas he has repopulated conifer forests with the intention of restoring the countryside and woods.

The dominant ecosystem is that of the pine grove with Phoenician juniper, which is restricted to ground with a carbonated substratum – specifically dolomite – with this ground being located in the greater part of this region. It constitutes one of the harshest and most selective habitats for vegetation, leading to the evolution of an open community which includes species such as the pitch pine, Phoenician juniper, the yew tree, prickly juniper juniperns oxycedrus, arctotaphylos uva-ursi, rock hawthorn or black hawthorn. In areas where mid-developed ground is formed, a high-reaching pasture establishes itself dominated by the laston and yesquera, together with other grasses such as trisetum velutinum or stipa dasyvaginata. In contrast, in those places which are the most exposed and lacking in soil, a small-sized, low-coverage shrub appears with a flower highly adapted to these conditions, such as arnica, zahareña (sideritis incarna), Spanish gold hardy broom (cytisus purgans), salamonda, broad-leaf lavender, centaura bombycina, and so on. There are frequently areas where the thyme grove dominates, together with the silver-plated bellflower, larrea divaricata, coloured thyme, pterocephalus stathulatus, viper’s bugloss, the common stork’s bill (machaonia woodburyana) and diverse types of woundwort. As far as the fauna is concerned, similar species exist to those which evolve at higher altitude, although in greater number. In invertebrates we find the scorpion, the spider, the pine processionary moth and other butterflies such as brintesia circe and issoria latonia, and beetles which eat dead wood and roots. The most significant vertebrates are the booted eagle, the great-spotted woodpecker, the coal tit, the crossbill, the Eurasian jay, the little owl, the common kestrel, the large mouse-eared bat, the fox, the white-toothed shrew, the southern smooth snake, the horseshoe snake, the ocellated lizard, the spine-footed lizard, the Spanish sand lizard, and Bedriagai’s skink, amongst many others.

Stretching across the siliceous materials situated between 1500 and 1900 metres, especially on both margins of the valley that forms the river Dúrcal, is the domain of the mountain holm-oak wood where the holm-oak dominates, together with bushes and shrubs such as the daphne gnidium, the leulen rose, the common madder, prickly juniper, honeysuckle, the butcher’s broom, the traveller’s joy (or old man’s beard) amongst many others. As this type of wood decays, due to the presence of moisture in the ground, thorny plants appear such as the dog rose, barberry, hawthorn, and the Sierra Nevada blackthorn (prunus ramburii). If, on the contrary, the ground is dry on the surface, the holm-oak wood becomes replaced by dense scrub popularly known as “escobonales”, dominated by the silver broom and distinct varieties of broom plants and the escobon (chamaecytisus proliferus). In cases where very significant disturbances occur, the cistus thicket becomes dominant, this including numerous species of cistus together with thyme, marjoram, gorse and so on.

Close to the holm-oak wood we come across the domain of the Pyrennean oak grove, which are wooded formations where the Pyrenean oak dominates. These formations appear in those areas where the ground is more acidic and moist, evolving in a strip which goes from 1100 to 1900 metres. In addition to the oak, other types of tree are to be found which appear in a scattered fashion, such as the gall oak, holly, the rowan (mountain ash) and the common whitebeam, and if we approach moister areas such as rivers, we find numerous ash trees, maples and wild cherry trees. The fauna is very similar to that preceding, but new species appear associated with this type of vegetation, throwing into relief the richness of species since food is abundant here. In any case, there are numerous differences between the species which inhabit the wood and those of the scrub. Woodland fauna, within the invertebrate group, includes the presence of various types of beetle such as the stag beetle or the enormous long-horned beetle. The most typical birds are the turtle dove, the common wood pigeon, the goldcrest, the woodpecker, the cuckoo, the Eurasian jay, the Eurasian sparrowhawk and the northern goshawk. The mammal group includes a few very striking species like the badger, the beech marten, the wild cat, the wild boar, the genet, the fox, the wood mouse, the garden dormouse, the common shrew, the grey rat, the large mouse-eared bat, and the “grande de montaña”. Amongst the most prominent reptiles and amphibians are the ladder snake, the Spanish sand racer lizard and the Iberian wall lizard, the common toad, and the natterjack toad. As for the scrub, other associated groups of species appear which prefer more open zones. Prominent amongst the invertebrates are the dorcadium mucidum beetle, the ururero, the tarantula and the scorpion, together with vertebrates as characteristic as the ocellated lizard, the Iberian worm snake, the false smooth snake, the savis pygmy shrew, the lesser horseshoe bat, and the fox. Abundant amongst the birds are the common kestrel, the blue rock thrush, the blackbird and the Sardinian warbler

Autora: María Dolores Chaves Fernández