Mediterranean ecosystems only occupy 1,2% of land surface and, as a result of its climacteric characteristics, are geographically well delimitated (31º – 40º north and south), in 5 disjoint regions of the globe, on the western shores of the continents: California, Chile, south of Africa, southwest of Australia and Mediterranean Basin. The largest is the Mediterranean Basin, which extends from Portugal to Lebanon, along about 3800 Km from east to west, and from the south coast of Italia to Morocco and Libya, along about 1000 Km from north to south.
In Portugal, most of the Mediterranean area is located between Tagus region and the South of the country, covering the entire region of Alentejo and Algarve.
 

Mediterranean Climate
Mediterranean Habitat
Biodiversity
Main threats
Main economic activities associated to the Mediterranean Landscape in Portugal
Useful references


Mediterranean Climate
The Mediterranean Climate is characterized by irregular rainfall and thermal regimes: rain is relatively abundant in winter (short but violent episodes) and very scarce in summer, with a low annual average rainfall (~275-900mm); regarding temperature and humidity, summers are hot and dry and winters are cool and moist, although unstable, with a moderate annual temperature range.


Mediterranean Habitat
The Mediterranean Basin comprises more than half of the habitat types listed in Habitats Directive (European Directive whose main objective is to contribute to ensure biodiversity through the conservation of natural habitats and wild species of flora and fauna considered threatened in the European Union territory), of which 37 only occur in this region. This diversity of habitats derives from a number of factors, including climate, the variable geology and the complex topography of the landscape and the fact that this region has not been seriously affected by the last glacial period that hit Europe.

The Mediterranean Basin is a very diverse region, topographically and scenically, with majestic mountains, deserts, rocky coastal areas, vast sandy beaches, forests and dense shrublands, pseudo-steppes, coastal wetlands and a myriad of islands of different shapes and sizes. It is a mosaic of natural and cultural landscapes, where human civilization and wild nature coexist for millennia.
This coexistence, characterized by the exploitation of natural resources through agro-forestry-pastoral activities, combined with high temperatures in the summer, led to the successive reduction of the original vegetation cover and, consequently, to the replacement of most of the initial Mediterranean forest by woods, scrublands and shrublands (mainly sclerophyllous) at different stages of evolution, and herbaceous communities (e.g. aromatic plants, grasses).

As a result, the Mediterranean landscape is currently composed by a set of different types of biotopes: forests, cork and holm oak woodlands (montados of Quercus suber and Q. rotundifolia, respectively), woods, wetlands, scrublands and shrublands and also some more degraded and arid areas only with annual plants or bare rock.
In Portugal, the biotope which earns more emphasis is the montado – the cork oak forests correspond to an area of approximately 736,000 hectares (70% of which in the Alentejo region), being the country, in the entire world, with the biggest area of this kind of forest (about 33% of the world’s total area), despite the small size of Portugal’s territory.

Forests
The existing forests are usually dominated by several species of the genus Quercus, but as the altitude increases they are replaced by sweet chestnut (Castanea sativa) and coniferous species of the genus Abies, Pinus, Juniperus and Taxus.

Montados
The montado is a forestry-pastoral or an agro-forestry-pastoral system developed throughout millennia, resulting from the opening of natural forests through the clearance of the canopy and the artificial management of natural forests, to obtain a long-term bigger productivity in often adverse conditions (poor soils and harsh climacteric conditions). It is a specific, semi-natural, delicately balanced ecosystem, where agriculture (pastures and cultivated fields) and livestock (in extensive regime) are naturally integrated in the wide forests of cork and holm oak.
The main functional and structural changes regarding the original forest habitat were: increase of the understorey cover insolation, disappearance of forest microclimate, changes in the forest floor, understorey removal, inhibition of natural regeneration, tree pruning and replacement of the understorey by enhancing non-forest vegetation in the understorey cover (pastures, heliofilus’ scrub, cereal crops, fodder, sunflower, etc.).
In the absence of management, many montados are not ecologically sustainable systems (pastures depend on the agro-pastoral system and the arboreal component on the forestry activities).

The changes to the original forest have resulted in a type of landscape in which ecological dominance is shared by:
(i) a remnant of ancient woodlands where the genus Quercus is dominant, with large areas of holm oak and shrublands (e.g. strawberry tree Arbutus unedo, kermes oak Q. coccifera, common myrtle Myrtus communis, laurustinus Viburnum tinus, asparagus Asparagus sp.), but mostly represented by cork oak; further north, Q. pyrenaica is also present; the tree density can vary from a nearly closed canopy to nonexistent;
(ii) a perennial cespitose pasture (growing in bundles) with its origin and persistence related with ovine’s extensive pastoral (e.g. Poa bulbosa, Trifolium subterraneum subsp. oxaloides, T. subterraneum subsp. subterraneum, T. suffucatum, T. tomentosum, T. nigrescens, Herniaria glabra, Parentucellia latifolia, Bellis annua subsp. pl., B. sylvestris, Erodium botrys, Gynandriris sisyrynchium, Leontodon tuberosus, Carex divisa, Paronychia argentea, Astragalus cymbicarpus, Onobrychis humilis, Hypochaeris radicata subsp. pl., Merendera filifolia, Plantago serraria, Ranunculus bullatus, and some annual species Ornithopus sp. pl., Astragalus sp. pl., Vicia sp. pl.).

The importance of montados
The great productivity of montados is only reached thanks to the central role they play in ecological processes such as, for example, water retention and regulation of the water cycle, soil conservation and CO₂ retention due to the unique cellular structure of the cork oak (it is estimated that, totally, the Portuguese montado annually retains 4,8 million tones of this important greenhouse gas). These characteristics have led montado to become an important refuge of biodiversity and source of natural resources (for animal and human consumption), being one of the most important conservational values of the Mediterranean Ecoregion.
Montados have the capacity to mimic natural Mediterranean ecosystems, therefore being very attractive alternatives both from an ecological and economical perspective, by housing a rich biodiversity and allowing in parallel the performance of a wide range of rural activities that are economically sustainable and important for the region, providing opportunities for development in areas socially and economically unprotected (as opposed to, for example, dryland crops or irrigation systems in which all or most of the trees are removed).
Montado is, undoubtedly, one of the best examples in the Mediterranean of the equilibrium between conservation and development in benefit of people and nature.

Shrublands
In several areas, the primitive forest gave place to two secondary formations, maquis and garrigues. These two types of shrublands are composed by shrub species of different sizes and shapes. Maquis are closed shrublands (difficult to penetrate) constituted by dense shrubs, with 3,28 to 13,12 feet tall, usually on siliceous or granitic rocky substrates, being the most common species the strawberry tree, mastic (Pistacia lentiscus), oleaster (Olea europaea var. sylvestris,) myrtle, gum rock-rose (Cistus ladanifer), heather (genus Erica and Calluna), gorse (Ulex spp), Cytisus spp, carob tree (Ceratonia siliqua) and kermes oak. Contrarily, garrigues are areas of more opened shrubs, consisting of more creeping shrub species (3,28 feet tall) and sparse, such as kermes oak, rock-roses and several aromatic species (e.g. Spanish lavander Lavandula stoechas, rosemary Rosmarinus officinalis, common thyme Thymus vulgaris).
The complex structure of vegetation also houses a great diversity of colorful flowers, like tulips, daffodils (Narcissus spp), saffron (Crocus sativus) and orchids.

Agricultural areas and pastures
These areas occupy about 40% of the Mediterranean Basin, from extensive areas of cultivation, olive groves and intensive orchards of citrines to a mosaic of assorted and smaller agricultural areas. Productivity is achieved even in the driest areas of pastures – through a system of rotating crops, farmers are able to produce cereals in those poor soils, like wheat, oat, chickpeas or barley. These areas are of great importance for steppe birds, such as the Great Bustard (Otis tarda), the Little Bustard (Tetrax tetrax) or the Calandra Lark (Melanocorypha calandra), all of them species that can be found in Alentejo’s pseudo-steppes.
 

Biodiversity
The unique combination of climate, the orography irregularity of the landscape (geology and biogeography of the region), high degree of natural disturbance (e.g. natural wildfires) and the history experienced by the Mediterranean ecosystem over time (e.g. area only slightly affected by the last glacial period), resulted in its unusual internal environmental heterogeneity, richer biodiversity and larger number of species that can not be found elsewhere in the world (endemism).
All 5 Mediterranean regions are included in the global list of the eco-regions that deserve special attention for conservation, as well as in the list of the 25 world’s hotspots with most biological diversity and endemic species in danger. In fact, if we think on biodiversity hotspots, the Mediterranean ecosystem is only surpassed by tropical forests, since they hold a wide floristic diversity.
In the Mediterranean Basin alone, one of the richest places in the world in terms of plant and animal diversity, and to which Portugal belongs, there are about 25 thousand species of vascular plants (10% of the world flora), 60% of which are endemic. There are more species of plants here than in all the other biogeographic regions of Europe together.
With such a rich floristic diversity, the fauna associated to this type of ecosystem is equally very diverse and well adapted to the climatic conditions of these regions. About one third of the fauna species are endemic to the region, particularly the groups of amphibians, crabs, reptiles, freshwater fish and macroscopic marine species.

Almost half of the species of flora and fauna listed in the Habitats Directive occur in the Mediterranean Region.

Flora
In an adaptive answer to climate, the vegetation of the several Mediterranean regions developed similar adaptations (shape and functional response). From this convergent evolution resulted trees and shrubs, usually small, with evergreen, sclerophyllous and small leaves covered with a waxy film – these characteristics help to preserve humidity and prevent losses of water through evapo-transpiration. These trees and shrubs have also developed numerous adaptations to natural wildfires, which are usual in this type of landscape, such as, for example, a thick and hard coat protects the plant tissue from high temperatures, ability to regenerate after fire by bursting (rhizomes, nied by hemoptysis or basal corms) and/or capacity to seeds’ germination stimulated by the high temperatures of fire.

From the trees and shrubs that characterize the Mediterranean forest, we must highlight the holm oak, kermes oak, cork oak, oleaster, genus Rhamnus and the pine tree, cedar and cypress.
As for the typical Mediterranean plants, most of which with leaves covered with aromatic oils, it stands out the genus Rosmarinus (e.g. rosemary), Lavandula (e.g. Spanish lavender), Thymus (e.g. thyme), Halimium (rock-roses), Cistus (e.g. gum rock-rose, C. ladanifer) and several species of the Origanum genus (e.g. oregano, O. vulgare). Of these, plants from the rock-rose family, like gum rock-rose, are the ones that better resist to the conditions of severe drought and infertile soils, being therefore common in degraded areas of the Mediterranean region, offering some protection to these poor and skeletal soils.

Fauna
According to a report from the International Union for the Conservation of Nature and Natural Resources (IUCN), the Mediterranean Basin alone holds 1912 species of amphibians, birds (especially migratory birds), cartilaginous fish, endemic freshwater fish, crabs and crayfish, mammals, dragonflies and reptiles. About 19% of these species are threatened with extinction on the regional and global level (5% Critically endangered, 7% Endangered and 7% Vulnerable) and at least 16 species have disappeared forever from this region, including some species that only existed there (e.g. Israel painted frog Discoglossus nigriventer, Canary Islands Oystercatcher Haematopus meadewaldoi, Sardinian pika Prolagus sardus).

Invertebrates
The diversity of insects and other invertebrates is massive, as a direct consequence of the number of plant species that exist in the region. Many have developed associations with specific plants and are now totally dependent on their presence to survive, just like the strawberry tree butterfly (Charaxes jasius), that feeds exclusively on strawberry tree’s leaves, where it also lays its eggs, or the Portuguese dappled white (Euchloe tagis), an ecologically specialist that, to survive, depends not only on the plant species of which its caterpillars feed on (genus Iberis) but also on a specific type of habitat, rich in calcareous soils.

Amphibians and Reptiles
While the eastern Mediterranean has a big diversity of reptiles (lizards, snakes, turtles and crocodiles), due to its arid characteristics, the more humid areas of the western Mediterranean have a greater diversity of amphibians. Of the 355 species of reptiles (excluding marine turtles) from the Mediterranean, almost half only exist there and 46 are at risk of extinction. Among the most important species are the leopard snake (Elaphe situla) and the Iberian rock lizard Lacerta monticola). As for amphibians, one out of four species is at risk of extinction and two out of three are endemic (of a total of 114 species), as it is the case of the Pyrenean frog (Rana pyrenaica), which only exists in the Pyrenees and is at risk of extinction.

Birds
Among the most endangered species of the Mediterranean Basin there are also some birds like, for example, the Spanish Imperial Eagle (Aquila adalberti), Bonelli’s Eagle (Hieraaetus fasciatus), Black Vulture (Aegypius monachus), Black Stork (Ciconia nigra) and Balearic Shearwater (Puffinus mauretanicus), all observed in Portugal, being the Spanish Imperial Eagle Portugal’s rarest bird of prey, with only 4 to 9 breeding couples.
The importance of the Mediterranean to wildlife is not limited to the richness or to the uniqueness of its sedentary flora and fauna: millions of migratory birds coming from the North of Europe and Africa use wetlands and other habitats of the Mediterranean as scale or as breeding and wintering places.

Mammals
One out of six mammal species (of a total of 330 species) are threatened with extinction on the regional scale and one forth is endemic. This list includes several species which are found in Portugal, such as the Iberian lynx (Lynx pardinus), the Mediterranean monk seal (Monachus monachus), the Pyrenean desman (Galemys pyrenaicus) or the Azores noctule (Nyctalus azoreum). The Iberian lynx is still considered the most threatened feline in the world and the most threatened carnivore in Europe, with only about 200 animals living in nature.
From this group we also highlight the wild rabbit (Oryctolagus cuniculus), a key prey of the Mediterranean ecosystem, namely the Iberian Peninsula, for being a landscape modeler (influence on plant communities) and for having an essential role in the Mediterranean ecosystem’s energy flow, by being an important prey of at least 39 species of predators, some of them threatened with extinction, like the Iberian lynx, the Spanish Imperial Eagle, the Black Vulture or the Bonelli’s Eagle. Object of a severe decline in the last decades, the wild rabbit is currently classified as Nearly threatened in Portugal. For being a ‘basis’ prey in the Mediterranean ecosystem, the decline of wild rabbit’s populations have weakened the entire trophic web, threatening profound changes in the native ecosystem.

Freshwater fish
In the Mediterranean Basin, at the hydrographic basins that flow to the Mediterranean Sea and at the Atlantic’s adjacent waters, there are 253 species of endemic freshwater fish. According to IUCN, in this category, eight species already went extinct and more than half (about 58%) are threatened, including several species native to Portugal, like Iberochondrostoma lemmingii, I. almacai, Anaecypris hispanica and Barbus comizo.


Main threats
The Mediterranean landscape is an exceptional center of diversity, of species and habitats, but also one of the most threatened. The balance that exists between vegetation, soil and climate is very fragile and, therefore, susceptible to rupture, namely as a consequence of certain human activities. Among them are: destruction of vegetation as a result of agricultural, animal husbandry and forestry management malpractices; hunting and fishing overexploitation; construction of big infrastructures (e.g. dams, roads); change of natural wildfire’s regime; quarrying and mining; urbanization; pollution; introduction of exotic species (e.g. eucalyptus Eucalyptus globulus, Louisiana crayfish Procambarus clarkii); and difficulties in the discussion and implementation of conservation measures and strategies in private lands.
The intensity of these impacts is determined by social-economic factors such as population growth or depopulation of rural areas, the government control on agriculture by the grant of subsidies, or the need to create richness through forestry resources, agricultural products and tourism.
Natural environmental catastrophes (much linked to the climate of the region) also act on these factors.

The protection of the Mediterranean region requires not only actions on the field to conserve species and habitats and to aware the population, but also adequate legislation and a more sustainable exploitation of natural resources.

 
Main economic activities associated to the Mediterranean Landscape in Portugal
In Portugal, the rural activities associated to the Mediterranean landscape with a bigger importance to the region, for its economic and resources’ sustainability, are: agro-animal husbandry, forestry, pastoral and its derivatives (e.g. cork, olive oil, cheese, sausages, ham, wines, medronho brandy, honey and wax), exploitation of game (hunting), fishery, traditional activities and ecotourism.

Cork
Cork is the thick bark that covers the branches and trunk of the cork oak tree and is periodically removed for its great commercial value and market applications. The main products of this raw material are cork stoppers. However, the lower quality cork and the one resultant from the milling of by-products have a wide application: floor and wall covering, decorative items, soles and other products for shoes, applications in the automobile, military and aerospace industry, or products for the chemical and pharmaceutical industry. The cork industry is unique for its eco-efficiency and its use is of 100%, because even cork dust can be used to produce electricity.
Montados are one of the few examples of fully sustainable forestry exploitation, even economically, because of cork’s market place. Portugal is the country with the world’s biggest industrial cork production and, in some villages, cork is the main source of income, keeping these areas economically viable, thus avoiding depopulation and desertification, by keeping montados ‘alive’.

Livestock husbandry
Breeding of livestock breeds well adapted to the demanding conditions of the region and raised in an extensive regime, like Serpentina’s goats, Merina Branca’s sheep, black-pigs and cattle of the breeds Alentejana, Garvonesa and Mertolenga. Also noteworthy are some derivatives, like leather and wool, used in craft work, traditional sausages that characterize and enrich the regional gastronomy, such as black-pig’s ham, fresh cheese, among others.

Hunting
Hunting is a practice as old as human societies themselves. Besides being an important recreational activity (culturally), it also ensures species’ maintenance, either game species or not, through the recovery and maintenance of habitats that otherwise could be lost to more erosive types of land use (e.g. intensive agriculture). Hunting is a very important economic activity in the Iberian Peninsula, with an estimated annual turnover of 350 million euros only in Portugal, helping promoting rural development, creating job opportunities and moving people, luring them to more depopulated areas.
The game species more explored in the Mediterranean landscape are wild rabbit, red-partridge (Alectoris rufa), wild-boar (Sus scrofa), hare (Lepus granatensis) and red-deer (Cervus elaphus). From these, the wild rabbit is one of the most hunted and, therefore, most important game species in Portugal and Spain. However, in the last 60 years, its populations faced a severe decline (to about 5% of its original size). Still, and although wild rabbit hunting has been replaced in some areas by red-partridge or big game hunting as a response to its decline, wild rabbit hunting continues to be an important cultural and economic activity. Therefore, currently many landowners and hunting managers invest a significant effort in time and financial and material resources for this species’ recovery.

Traditional activities
Schist, clay, iron, wood, wicker, buinho, wool, leather, linen, among others, are transformed by artisans in local crafts (e.g. footwear, clothing, wicker basketry, buinho’s chairs) that keep the region’s habits and traditions alive.

Ecotourism
Ecotourism is a way of nature tourism aimed at a sustainable enjoyment of natural heritage (e.g. bird-watching), encouraging its conservation, while it searches for the creation of an environmentalist consciousness, through the interpretation of environment, promoting well being and benefiting local populations. Ecotourism also works as an important marketing vehicle to attract potential dwellers and new companies to areas often abandoned and depopulated.

In addition to these activities, there are also many natural resources that can be collected and that represent an extra source of food or income for local populations, such as medicinal plants (e.g. St john’s wort Hypericum perforatum), aromatic plants (e.g. oregano, rosemary, pennyroyal Mentha pulegium), plants used in cooking (e.g. asparagus), acorns (of great importance in the diet of livestock bred in an extensive regime), wild mushrooms or even gum rock-rose, which is used as firewood for the traditional bread ovens or for the extraction of essential oils (laudanum) for the perfumery industry.


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