Cabañeros National Park

The ‘casqueras’ of loose quartzite blocks and clasts are more a result of the washing of fine materials than of the fall of clasts from the ridges (the fragmentation processes are currently at a standstill), and are located in the sectors of the slopes where the subsurface flow of water is still active and are filled in, fixed and colonised by vegetation where the aforementioned flow does not occur or ceases to act. In most of the T oledo Mountains, where the current hydrographic network has already been installed, the initial runoff of water captured in the mountainous reliefs has ceased to be diffuse on the slopes and has been concentrated in well-marked torrential headwaters, where large and active “pedrizas” can be observed, the rest being basically stabilised and accessible in the medium term to plant colonisation; but in the Chorito massif, due to its hydrographic setting in the Bullaque basin, where – as has been said – there has not been a marked incision in the network of watercourses, the loose scree coverings are more diffuse on the slopes, forming a strip at medium height, which separates the basal levels from the culminating ones (the “casqueras” are not as clear and concentrated, nor do they have the characteristic fan shape of other places, but they have greater continuity and reach a greater relative extension).

The movement of water within the rocky areas is very evident; in fact, the inhabitants of Los Montes were able to locate subsurface flows by noise, and they opened small wells by removing stones, in order to reach the water in areas as dry as the highest slopes.

The fragmentary debris of the highest screes (above 1,000 metres) has hardly been broken up and the oak trees are already growing on them. The appearance of these forests is surprising, as the trees seem to grow among the loose rock. The explanation for this is simple: the pedriza is a good thermal insulator (it is often said that “the pedrizas keep cool”) and attenuates the water deficit as there is no loss of water through direct evaporation from the ground, as there is no capillary rise due to the existence of an upper chamber of loose stone that causes discontinuity.

During the winter months, and some of the autumn and spring months, the average temperature recorded in the synclinic depressions of the raña is lower than those measured on the middle slopes and even on the peaks of the latter, as a result of the fact that, during the night, cold air accumulates in these interior foothills affected by stagnation phenomena, with thermometric levels being below those that simultaneously occur in the prominent mountainous reliefs (in a typical phenomenon of <<thermal inversion>>). During the day, persistent fog banks generated at dawn remain on these foothills, over which the high slopes and peaks of the mountainous sector of Cabañeros remain, with a higher calorific content in the air and exposed to sunlight. The reason for these characteristic condensation phenomena, in addition to the drop in air temperature at the lowest levels beyond the “dew point” (and even 0°) due to the aforementioned stagnation effect, lies in the abundance of surface water in the large ravine plains where, exceptionally, the numerous and relatively abundant watercourses, There are many waterlogged or imperfectly drained areas due to the formation of argic horizons, which are capable of maintaining the air above them with a high degree of absolute humidity (and therefore very susceptible to the formation of fog).

Thus, the wild olive tree, the paradigmatic tree of the more thermal areas of the Mediterranean, which should be present in the rañas, appears only on the summits, and in a strip from 950 m altitude, which is the height from which the summits rise above the “sea of clouds” formed by the mists.

The birch is a typical species of optimal Eurosiberian forest that expanded southwards after the recent Dryas (10,000 years ago), which led to the coexistence of Eurosiberian and Mediterranean species on the Central Plateau, giving way in the period between 4,000 and 2,000 BC to a period of no summer dry period, with a marked expansion of the species and other boreal deciduous forests of holly, hazel and alder.

The birch is characterised by its striking white bark, with dark-coloured, elongated, horizontal lenticels, a distinctive feature that has probably led to the local confusion of calling the birch ‘choyo’. The leaves are pendulous, rhomboidal and finely serrate.

The copses occur in secluded mountain streams with a permanent course and, in a single case, on a foothill in the Chorito massif, at an altitude of just over 650 metres. They constitute relict communities, in which the birch is accompanied by many species that are rare in the rest of the Park, such as holly, arraclan or biondo and various species of ferns.

The birch, a species with a markedly heliophilous character, sprouts vigorously from the stump as gaps are created in the forest when the trees fall. This is visible in the birch grove of La Ventilla.

A similar series are the Oretan laurophyllous galleries, made up of loro (Prunus lusitanica).

In some cases (Cebea stream, in the Chorito massif), holly appears in small stands – mostly on stony ground – mixed with strawberry trees, gall oaks, arraclanes, mustards and oaks, with a large development of wild vines. The birch, which is much more demanding in terms of soil moisture than holly and the rest of the species in the cortege, has probably disappeared from these areas beforehand.

The peat bogs, locally known as “trampales”, are unique spots in the sierra. Their waterlogging prevents the existence of nitrifying bacteria, resulting in a significant nitrate deficit in the soil. Despite this, peat bogs are full of life and are one of the best examples of how organisms adapt to their environment. Very close to the water, in the interstices of the peat bog, live carnivorous plants, which obtain nutrients – and especially nitrogen – by digesting the proteins of their prey.

We find the pinguicola (Pinguicola lusitanica), a terrestrial plant with a basal rosette of leaves covered with viscous glandular hairs that attract and retain insects, and the flytrap (Drosera rotundifolia). The latter has leaves with sticky hairs to which the insects adhere. The desperate movements of the prey cause the other hairs to move and the leaf to curl up and open again after digestion. Mosses such as Sphagnum, which can store large quantities of water even from the atmosphere, appear everywhere forming colonies.

On the surface of the peat bog the dominant plant is the bog heather. To survive in this inhospitable environment, it has to associate with a fungus in a symbiosis known as mycorrhiza: the fungus penetrates the roots of the young plants and takes up carbohydrates, providing in return a highly complex root system capable of capturing scarce nutrients. Other plant species associate with bacteria capable of assimilating atmospheric nitrogen. This is the case of the Brabant myrtle, which has its southern limit here.

In the lower areas of the rañas (between 620 and 750 metres above sea level), the potential vegetation is a community with holm oak as the dominant tree, originally constituting even a dense and shady forest. However, these flat areas were the ones most used by their owners and settlers, and the ones that most felt their main tool: fire.

A highly fragmented (and constantly rejuvenated) artificial landscape of rockrose and heather thickets, dotted with holm oaks, gall oaks and pyrope trees, was thus shaped. It was an optimal habitat for a fundamental species in the Mediterranean mountain food chain, the rabbit, and for its predator par excellence, the lynx. This changed radically in the 1950s, when the massive clearing of the scrubland began, resulting in the current “African” landscape of Cabañeros, consisting of grassland with scattered trees.