Flora of Cantabria

The flora of Cantabria is the result of three determining factors: the climate, the composition of the soil, directly dependent on the types of existing rocks, and the evolutionary history of the different plant formations.

This border situation has a direct effect on the characteristics of the plant landscape of the region, where Mediterranean and Atlantic species intermingle, enriching the botanical composition of the different existing ecosystems.

In the rest of the territory, human action has caused the degeneration of the forest and the appearance of substitution stages, made up of heaths and scrublands, and finally of pastures and meadows, the basis for livestock feeding.

This area has been the most transformed by human development, as it is here that the majority of the population and a large part of the infrastructures and intensive exploitations are located, so its ecosystems show a significant degree of alteration.

In the area closest to the sea, where the grains of sand deposited by the tide are intercepted, slightly above the average high tide, the first band of pioneer dune vegetation begins to settle, represented in Cantabria mainly by the northern couch grass (Elymus farctus), generally accompanied by the prickly saltwort (Salsola kali), the searockets (Cakile maritima) and the arenaria (Honkenya pelopides).

A certain stabilization of the dune occurs in this growth zone as a result of the settlement of vegetation that reduces its mobility, especially the beachgrass (Ammophila arenaria), which due to its wingspan and intricate root system, is the main fixative plant in this environment.

Beyond the strictly coastal area, the vegetation landscape is characterized by the dominance of intensively managed mowing meadows, in which forage gramineae such as Lolium perenne, Holcus lanatus, Anthoxanthum odoratum, etc.

These meadows are the plant formation that occupy the largest area in the region, distributed in large spaces with very few trees on their margins and with hardly any hedges separating the farms.

They are composed of a mixture of different species, among which the common oak (Quercus robur) dominates, accompanied by ash (Fraxinus excelsior), maple (Acer pseudoplatanus), birch (Betula celtiberica), linden (Tilia spp.

), chestnut (Castanea sativa) and a large number of tall shrubs such as the common hazel (Corylus avellana), the alder buckthorn (Rhamnus frangula), dogwood (Cornus sanguinea) or laurel (Laurus nobilis), interspersed with lianas and epiphytes, thickets and herbaceous plants.

Within the colline level of the region, on the rocky limestone beds, and in general on carbonate rocks, a plant formation of major interest is developed, called Cantabrian holm oak forest.

These holm oak forests, located outside their climatic optimum, need a substrate of a certain degree of aridity, so they take refuge in the limestone rocks due to their high permeability.

In the herbaceous stratum, Carex remota, C. pendula or Bromus ramosus stand out together with widely distributed plants such as nettle (Urtica dioica), which are favored by the detritus provided by the floods in these areas.

When the valleys are very steep, the surface that can occupy the riparian forest is reduced, even disappearing and being replaced by mixed oak groves, as happens in the middle stretch of the Miera in Mortesante or in the Nansa, in the town of Rozadío in Rionansa.

S. cantabrica and S. atrocinerea dominate the willow groves of the southwestern part of the region, which prefer streams that maintain a constant minimum level that is not excessively torrential.

The plantations existing in Cantabria - in no case repopulations, since it is an exotic tree - constitute the largest extensions of this species in the European continent and in many occasions they have been planted at the cost of previously destroying the real autochthonous Cantabrian forests.

On the other hand, given that these studies on the regeneration of native species are carried out by the General Directorate of Forestry and Tragsatec, which are interested parties in the pulp business, their credibility is null and void.

These forests remain in the form of isolated patches, generally at the head of valleys and on steep slopes, not very accessible to human activity, in contact with the rocks and high pastures, already at the upper limit of the montane level.

or chestnut trees (Castanea sativa) and a large number of shrubs such as holly (Ilex aquifolium), blackthorn (Prunus spinosa) or hazel (Corylus avellana).

This type of forest has suffered a strong regression as a result of its exploitation for shipbuilding[6] during the sixteenth and seventeenth centuries, and for its use as fuel in forges and in the Royal Artillery Factory of La Cavada, so its sparse and fragmented distribution may endanger the persistence and recovery of this species, symbolic par excellence for the pre-Roman peoples of the northern Iberian Peninsula.

The last surviving oak forests in Cantabria are located in the mountain range that separates the Saja and Besaya valleys, such as those of Rucieza and Guzaporos in Cieza, Montequemau and Rodil in Iguña, Monte Aá in Ruente or Viaña in Cabuérniga.

The sessile oak grove (Quercus petraea) replaces the ones found in the higher elevations, in more inland territories and isolated from the sea, of continental character, although sometimes hybridized with the previous ones and extending up to 1700 meters of altitude approximately, preferably on slopes with sunny exposure.

The shrub layer of these environments is mainly composed of heather (Erica arborea) and broom (Cytisus cantabricus), interspersed with holly (Ilex aquifolium) and hazel (Corylus avellana).

The distribution of this type of forest in Cantabria includes the interior valleys of the south and west of the region, from Liébana and Polaciones to Campoo, the upper basin of the Saja and Valderredible, where the best preserved example is found on Mount Hijedo.

Other tree species accompanying them are ash (Fraxinus excelsior) or maple (Acer campestre), while the shrub substrate is mainly composed of blackthorn (Prunus spinosa), holly (Ilex aquifolium) and broom (Cytisus cantabricus).

In Cantabria, there are only a few isolated forests in places with particular mesoclimatic conditions, as is the case of the regions of Liébana or Campoo-Los Valles, where they always appear on limestone substratum on steep slopes and sunny orientations, between 700 and 1000 meters above sea level.

The birch is accompanied by a few trees, including rowan (Sorbus aucuparia) and some isolated specimens of beech (Fagus sylvatica), the undergrowth being occupied by species characteristic of the Cantabrian high mountains such as heather (Erica arborea, Calluna vulgaris), broom (Genista spp.)

The dominant species, the cork oak (Quercus suber), is accompanied by a rich shrub substrate formed mainly by strawberry trees (Arbutus unedo), buckthorns (Rhamnus alaternus), sloes (Prunus spinosa) or hawthorns (Crataegus monogyna), as well as some brooms (Cytisus cantabricus, Genista spp.).

alpina) accompanied by other species such as the bearberry (Arctostaphylos uva-ursi) or the spurge-laurel (Daphne laureola), which takes refuge in the crags, spurs and stony ridges, in biotopes covered for a short time by snow.

In long snow-covered substrates, on more acid soils, present only on the summit of Peña Prieta, the grasslands are formed by species such as Festuca eskia, Juncus trifidus or Luzula hispanica.