Flora of the Canary Islands. Relief of the Canary Islands. Flora and vegetation of the Canary Islands

The topography of the Canary Islands

      The topography of the Canary Islands is the result of the ongoing process of creation and destruction of the volcanic materials that form the islands. The creation of the topography is caused by the successive volcanic eruptions that have taken place throughout the archipelago’s geological history, whilst its destruction is caused by various erosive processes: water, snow, winds, tides, landslides or implosions, etc.
    This has given rise to a highly diverse landscape, in which each of the islands has a distinct and unique appearance, which depends directly on its past volcanic activity, its geological age, and the resistance of its materials to erosion.
      All the islands, except Lanzarote and Fuerteventura, reach their highest points in the central areas, and the terrain slopes downwards from there towards the coast. From these higher areas, steep slopes descend, accompanied by deep ravines that reach down to the sea. This topographical layout, together with the characteristics inherent in being an archipelago situated in the Atlantic Ocean off the coast of Africa, gives rise to a unique and exceptionally beautiful landscape, with a wide variety of soils, climates and vegetation.
    The predominance of this mountainous terrain also has a significant influence on the atmospheric dynamics of the Canary Islands, as the highest mountainous areas act as a veritable barrier to air masses; when these collide with them, they are forced to rise, causing them to cool, condense and release moisture on the north-facing slopes, which are exposed to the wind. Consequently, the mountainous islands are more humid than the flat ones, and, within the mountainous islands, the north-facing slopes are more humid than those facing south, which has a significant influence on the islands’ vegetation.

Types of landform

Among the wide variety of landforms found in the Canary Islands, the most notable are as follows:
Ancient massifs. The oldest parts are known as ancient massifs, which are the result of the most primitive volcanic processes on each island. These landforms are found in Gran Canaria, La Gomera, the south of Fuerteventura, the north of La Palma, and certain areas of Tenerife and Lanzarote. They generally form the backbone of most of the islands, comprising vast volumes of material that have accumulated to considerable heights, and are criss-crossed by a dense network of dikes and ravines.
The main examples of this landform are the Famara and Los Ajaches massifs in Lanzarote, the Betancuria massif in Fuerteventura, the Tamadaba, Güigüí and Inagua-Pajonales massifs in Gran Canaria, the Teno, Anaga and Adeje massifs in Tenerife, the northern half of the island of La Palma, and the entire island of La Gomera. The only island that does not feature this type of terrain is El Hierro, the youngest in the Canary Islands, where not enough time has yet passed for water to have had such a significant impact on the landscape.

Ridge systems. Ridge systems are imposing volcanic structures formed by the accumulation of lava emitted along the archipelago’s main structural lines. They play a fundamental role in the development and configuration of the islands, and are key triggers of the massive gravitational landslides that will give rise to the large valleys and calderas.
Most historical eruptions have been concentrated along these ridges, and the same will be true of future eruptions. This recent eruptive activity – the last few thousand years in geological terms – can be clearly observed on the Cumbre Vieja ridge on the island of La Palma, which has been formed by the successive aggregation of elongated mountain ridges that slope down towards the sea on either side of the volcanic chain.

    The most prominent ridges in the Canary Islands are the Cumbre Vieja ridge, to the south of the island of La Palma, and the La Esperanza ridge, also known as the Pedro Gil ridge, on Tenerife.
    The ridges of La Palma and El Hierro extend out into the sea, suggesting that, in the geological future, these islands will develop much further.
Valleys and calderas. Valleys and calderas are important and characteristic features of the Canary Islands’ landscape, and their origins and formation are varied.
    The most significant valleys are believed to have been formed by large gravitational landslides; the most notable formations of this type are the La Orotava and Güímar valleys on the island of Tenerife, the El Golfo and Las Playas valleys on El Hierro, and the Aridane Valley on the island of La Palma.
    On the older islands, such as Lanzarote and Fuerteventura, where erosion processes are well advanced, the valleys have very open shapes and flat bottoms; the headwaters have disappeared, giving way to inland plains that connect one valley to another, with no topographical features to separate them. These are more or less levelled landscapes, without steep gradients and with an abundance of sedimentary deposits.

Calderas also exhibit a variety of formation processes. In Tenerife, the Caldera de Las Cañadas is particularly noteworthy; it is actually two joined semi-calderas formed by two distinct major gravitational landslides. The other major structure of this type in the Canary Islands is the Caldera de Taburiente, on La Palma, which occupies roughly the central part of the island and was formed by a combination of volcanic processes, gravitational landslides and severe erosion caused by surface runoff.

Coasts. The Canary Islands’ coasts take on different forms due to the constant process of marine erosion to which they are subjected. Their shapes are highly varied, and generally consist of imposing cliffs, lava slopes that reach down to the sea forming low-lying islands, rocky coastal strips, or large beaches of black or yellow sand. High coastlines with steep, rocky terrain, formed by cliffs, predominate, and there are very few areas of sediment accumulation, which means there are very few natural beaches.
However, on the eastern islands, low-lying coasts are common, consisting of low-lying areas where yellow sandy beaches predominate due to the direct supply of sand carried by the south-easterly winds from the African continent. The most notable of these are Papagayo and Mujeres on Lanzarote, Corralejo and Jandía on Fuerteventura, and Las Canteras or Playa del Inglés on Gran Canaria.

Gorges. Gorges are one of the most common landforms in the archipelago. They are very narrow, deep valleys wedged between steep mountain walls. They are short in length and generally have a very distinct straight profile, and the riverbed is covered with debris carried by the water.
They were formed by torrential waters which eroded and dismantled the volcanic landforms during a bygone era characterised by abundant and regular rainfall.
The ravines are found in the ancient massifs, which have been most affected by erosion, such as Anaga, Teno and Adeje on Tenerife; the northern part of La Palma; the west of Gran Canaria; and almost the whole of La Gomera.

Recent volcanoes. One of the most distinctive features of the Canary Islands’ landscape is its recent volcanic formations. The youngest materials are the most spectacular, as they are the most visible – not yet covered by vegetation – and were formed by historical eruptions that affected some of the islands in the not-too-distant past.
They overlie previously formed structures and, in many cases, have reached the sea, increasing the islands’ land area. Notable examples include the historic eruptions at Timanfaya, which took place on the island of Lanzarote between 1730 and 1736, and the most recent volcanoes on the island of La Palma, such as San Juan and Teneguía.

Coastal rocks. Sea stacks are a common feature along the Canary Islands’ coastlines, formed as a result of the retreat of the former shoreline due to intense erosion. They remain as upright remnants that were not eroded, thanks to the resistance these materials offered against the waves.
The best known for their visual appeal are the Roques de Salmor and the Roque de Bonanza on El Hierro, the Roques de Anaga and the Roque de Garachico on Tenerife, and the Roque de Gando on Gran Canaria.

Natural regions. Depending on the topography, altitude and aspect in question – and particularly on the islands with the most rugged terrain or greatest altitude – we may find natural regions that encompass summit, mid-altitude or coastal areas, and even continuous areas that include several of these spaces or zones, and the varying degrees of slope within each area give rise to a wide variety of microclimates, resulting in different types of landscape within the same region.
On islands such as La Gomera and Gran Canaria, this results in radial regions due to the ravines that largely characterise their distinctive relief. On Tenerife and La Palma, two high islands with ridge-shaped peaks—one running perpendicular to and the other parallel to the direction of the trade winds—natural regions form on both sides of the ridges, in addition to those on the peaks themselves, extending from these peaks down to the coast. El Hierro exhibits a similar pattern, although less varied due to its status as a young island that formed rapidly. Lanzarote and Fuerteventura have a lower diversity of regions, as well as larger ones, logically due to their gentle topography and low elevation.

It is important to note that the size and boundaries of the regions are determined by the topography and geology of each island – some of which have very recent and active volcanic activity – as well as other biological and environmental factors, in the case of the landmass, and the slope, seabed type, marine currents and temperature, in the case of the island shelf.
Consequently, alongside large natural units, there are also small habitats which, in many cases, are home to unique and extremely unstable ecosystems, as well as local endemic species of great biological importance.