It is the roof of the Iberian Peninsula. Sierra Nevada is a mountain range located in the Penibaetic System in the region of Andalusia (Spain). Between the provinces of Granada and Almería, Sierra Nevada covers 90 kilometers long and its highest peaks rise to over 3,000 meters (9,842 ft) in the western part.

The gentle relief forms of this mountain, due to erosion, contrast with the steep slopes that formed after the action of ice during continuous glaciations in Europe.

Almost reaching the sky, west of Sierra Nevada, Mulhacén stands as the highest peak in the Iberian Peninsula with its 3,482 meters (11,423 ft). It is named after Abu-l-Hasan Ali, known as Muley Hacén in Spanish, the penultimate Muslim King of Granada who, according to legend, was buried with treasures on the summit of the mountain where no one could reach.

Next to Mulhacén, Veleta rises 3,395 meters (11,138 ft) above sea level. Perhaps this is the most emblematic peak due to its characteristic shape. In third place is the Alcazaba, whose peak is 3,371 m (11,059 ft).

I. Origin and characteristics

The ridges on the Mediterranean Sea emerged because of the Alpine orogeny, a process that began raising these formations over 20 million years ago. The African Plate pushed northward and collided with the southern edge of Europe; the result was the emergence of the Alps in Central Europe, the Atlas Mountains in northwest Africa and the Baetic System in the southern and eastern Iberian Peninsula.

Mulhacen and Veleta peaks. Photograph by Nacho Castejón

In the central sector, one can observe the consequences of glacial erosion and periglacial modeling, which come from approximately 10,000 years ago, after the last glacial period. The footprint of these glaciers of modest proportions is present in the cirques (such as the Veleta, the Alcazaba and Mulhacén), in numerous lakes formed by abrasion (such as the Caldera or Aguas Verdes) and in the spectacular Crestones de Río Seco.

Valleys and depressions accentuate this orographic barrier, revealing inaccessible cliffs and vertical walls that have impeded traffic for centuries with an access that has become often very laborious.

The Veleta cirque and the Caldera. Photograph by Por los caminos de Málaga

Climate

In Sierra Nevada, several factors combine to shape an exceptional climatic diversity: its intermediate position between the Mediterranean and Atlantic atmospheric fields, its location that covers much of the southeastern Spain and its characteristic altitude. These entire circumstances make the climatic conditions here very different from those typical in the Mediterranean climate.

Here, in just a few kilometers, you can pass the subtropical climate of the coastline up to the alpine tundra in the high peaks, where little vegetation grows. In summer, a traveler can go from 40 °C (104 °F) at the foot of the mountain to five (41 °F) at the top of Mulhacén Peak.

Photograph by Dale Harvey

The northwestern part of Sierra Nevada welcomes air masses, which come from the Atlantic Ocean. The altitude causes condensation and abundant precipitations during autumn, winter and spring. As we move towards the southeast end, rainfall becomes increasingly rare, revealing the typical sub-desert landscapes of Almería.

Thus, the western summits have a humid climate, reaching 1,800 mm (70.9 in) per year. At the opposite extreme, the semiarid climate extends over vast areas characterized by drought. For example, in the valley of the Andarax, the rainfall rarely reaches 200 mm per year (7.87 in). This clear contrast allows the existence in Sierra Nevada of all bioclimatic zones that are present in the Mediterranean region.

Hydrography

Thick snow layers on the high peaks feed the numerous rivers and streams that flow in Sierra Nevada, forming a large and important river system. At the western end and flowing through the Lecrín Valley, the Dúrcal River collects water from other minor rivers born in the core of the mountain.

To the south in the Alpujarra, three major rivers irrigate the fields: Guadalfeo, Adra and Andarax. Distributed throughout the southern slope, these rivers receive their water from snowmelt, increasing their flows during the months of spring and early summer. This river system has sculpted the landscape using erosion to model majestic cliffs and canyons.

Photograph by Mirko Tobias Schäfer

To the north, the Genil River goes along the northern slope of the mountain to its mouth in the Guadalquivir. After this, the Genil is the second longest river in Andalusia.

II. Wildlife

The unequal heights, from river valleys, plains and depressions to the most formidable elevations, have allowed the existence of an exuberant biodiversity. In Sierra Nevada, we find species from the Mediterranean region and others that came from Africa and Central Europe; apart from this, the evolution has led to the emergence of numerous endemic species.

Photograph by rjime31

The existence of plants and animals from northern Africa is the result of the Mediterranean desiccation that occurred about 6 million years ago. A million years later, the seawaters broke again the continental physical union, separating these species. The glaciations of the last two million years also helped extend southward species from the Nordic lands, trapped in high levels of the mountain after the arrival of warmer temperatures. It is no wonder that Sierra Nevada shares more than 70 species with the Alps in Central Europe.

Thus, geographical location, altitude or the climatic conditions are factors that have converted Sierra Nevada in one of the richest regions in Spain and Europe in terms of animal biodiversity and number of endemic species.

1. Flora

In Sierra Nevada, one can distinguish five bioclimatic zones from the Mediterranean region:

• Mediterranean level (800 to 1,200 m)

Mainly located in the area of the Alpujarra and, more specifically, near Lanjarón and Órgiva, the Mediterranean level has a wide distribution of orange and olive trees, and here we find the presence of fig trees.

• Meso-Mediterranean level (800 to 1,400 m)

Traditionally, this was the area of the evergreen oak par excellence. Primitive deforestation gradually reduced the ancient oaks and now we also find here peonies, the common hawthorn, the flax-leaved daphne, the common honeysuckle, the common juniper, rough bindweed, hellebore, etcetera.

The disappearance of evergreen oak, erosion and soil degradation have led to emergence of bushes such as sage or rosemary. Here, it is possible to find the black pine.

• Supra-Mediterranean level (1,400 to 2,000 m)

As you ascend, the oaks share the land with deciduous trees such as the field maple, the common whitebeam and the service tree. The most extensive forests of this nature are in the head of the Alhama River, in the shady slopes of some rivers (Genil, San Juan, Monachil and Dúrcal), as well as in the mountains of Cáñar, Soportújar, Pórtugos and Busquístar.

The shrub layer contains rose hips, common hawthorn, honeysuckle, hellebore and common foxglove.

• Oro-Mediterranean level (2,000 to 2,900 m)

In addition to the pine, some tree species from the previous level survive up to half the Oro-Mediterranean level. Around these species, the Genista baetica grows with the common juniper and fescues. Other species that also appear here are the Leontodon boryi, the Jasione crispa and the Sideritis glacialis.

• Alti-Mediterranean level (2,900 to 3,482 m)

Similar to the arctic tundra, this level is the most interesting and surprising from a botanical point of view, finding here the largest number of endemic plants in Sierra Nevada. The continued presence of snow for more than eight months a year and a short summer period impede the growth of trees and woody plants.

The Viola crassiuscula, Erigeron frigidus, Festuca frigida, Linaria glacialis or the Rhynchosinapis cheiranthos are some examples of the huge number of endemic species found at this point.

2. Fauna

The cliffs near the peaks may appear lifeless, but if you look carefully, you can also see that many organisms have adapted to the climatic conditions of the area. Here, among the invertebrates, one can find numerous butterflies and endemic Lepidoptera: we highlight the Apollo or Parnassius apollo nevadensis. The exclusive species are also among the order Coleoptera (beetles) and other invertebrate groups, a number that continue to grow as new studies are made throughout Sierra Nevada.

Regarding vertebrates, birds are an important and large group. For example, if we are on the highest peaks, we can observe the alpine accentor, which often settles on the rocky slopes and high mountain meadows. Other birds that inhabit this mountain are the northern wheatear, the black redstart, the red-billed chough or the rock bunting.

From the sky, we distinguish the golden eagle by its brown plumage. Its powerful view, strong legs ending in sharp claws, a hooked beak and speed are essential for the eagle to have success hunting. It is not the only bird of prey that have settled here; other species are widely distributed across this land such as the Eurasian sparrowhawk, the northern goshawk, the common kestrel, the Bonelli’s eagle, the common buzzard, the little owl or the Eurasian eagle-owl.

In the highest peaks, the European snow vole is practically the only mammal adapted to survive the frigid environment. The Iberian ibex often ascends to these cliffs in search of grass during the summer; in winter, the ibexes come down to shelter from the cold weather. In Sierra Nevada, the presence of this species is significant and it has been increasing in recent years due to human protection.

We can find other mammals in the wooded areas of forests such as the red fox, the European badger, the forest polecat, the least weasel, the common genet, the stone marten, the red squirrel and the wild boar.

However, the presence of amphibians is poorer with the common toad as most widespread species, which can reach up to 2,500 meters during the summer. Possibly, the shortage of amphibians in these lands is due to the low temperatures of the mountain streams and its tremendous slopes.

Regarding the reptiles, the Montpellier snake and the ocellated lizard are distributed in abundance, without reaching the high peaks inhabited by the Vipera latastei and the Iberian wall lizard. The viperine water snake is found in rivers and aquatic environments, where the fish fauna presents the brown trout and the rainbow trout. In these river sections, we also find invertebrates like snails, bivalves and crustaceans.

III. Human footprint in Sierra Nevada

Sierra Nevada has witnessed an ancient occupation of man. From time immemorial, agriculture has been the main economic asset due in large part to the abundance of water in the western part.

Another hugely important work was transhumance, the seasonal movement of people with their livestock between fixed summer and winter pastures. In summer, with snow already disappeared, shepherds climb the mountains and cliffs in search of high mountain pastures or borreguiles, located more than 2,500 meters. Today, this activity is disappearing at a high speed.

Photograph by José Sáez

The stable population centers were established around olive trees, almonds and vineyards, and next to cereal plantations including wheat, barley and rye. Deforestation was also essential for the development of this region; however, today has been restricted with a particular vigilance in order to avoid damaging wildfires.

As for mining, it is currently prohibited in the National Park although once had some significance in this area (Alquife and Conjuro mines). All these human activities decrease today while tourism grows in importance; the favorable climatic conditions, the varied hiking trails and the famous Sierra Nevada Ski Station make this mountain range one of the main touristic attractions in southern Europe.

Photograph by Oliver Clarke

IV. Routes and trails

The Sierra Nevada National Park displays a vast network of routes and trails in an extraordinary variety of landscapes and ecosystems of this mountain range. It is an attempt to maintain the links between people settled here and traditional activities.

Near the Poqueira Valley and Bubión, roads and paths are numerous and allow us to ascend the mountain, admiring the natural and ethnological wealth of agricultural uses (terraces, acequias, eras and cortijos) around these small population centers.

Acequias del Poqueira

The Poqueira Valley, for its spectacular beauty, is the most famous image of the Alpujarra and best defines the harmonious relationship between nature and human, with its hilltop villages perfectly integrated in their environment. UNESCO declared Sierra Nevada a Biosphere Reserve in 1986. The organization valued the unique folk architecture, agriculture, irrigation ditches (acequias), traditional activities...

Photograph by Ronnie Macdonald

The proposed route will illustrate us about these human activities in a rugged geography, wisely exploited by its inhabitants.

Hoya del Portillo - Poqueira Refuge

Among the itineraries to climb to the Poqueira Refuge, this is the most affordable because we start from a height of 2,150 meters,  where is located the Hoya del Portillo, in the Sierra Nevada National Park. From here we can make various itineraries to the high peaks and the surrounding villages.

The journey to the Poqueira Refuge allow us to explore the spectacular heights of the Poqueira Valley crowned by the Mulhacén, Veleta and many lakes such as the Caldera or Río Seco, all with a magnificent glacier morphology.

La Cebadilla

This route starts from Capileira and goes to where the Toril and Naute Rivers meet, through one of the most beautiful places in the southern Sierra Nevada slopes. In addition, it presents the opportunity to enter Capileira and admire its streets and buildings, which are example of urbanism in the Alpujarra.

Photograph by Jeanne Menjoulet

The Poqueira villages

This interesting route through the Poqueira Valley, one of the most beautiful landscapes in the region of the Alpujarra, stops at three small villages that have carefully preserved traditional architecture: Pampaneira, Bubión and Capileira.

It also offers the opportunity to enjoy the rural countryside, perfectly integrated in the natural environment, which is part of the Moorish legacy.

 

Natural, botanical and environmental values of Sierra Nevada have been crucial for it to be declared as National Park in 1999, Nature Park (1989) and Biosphere Reserve by UNESCO (1986).