Please find in this section several possibilities for birdwatching, dolphin observation and various tours to view and learn about Algarve's natural treasures in an interpretive way under guidance of duly licensed and certified nature guides.
To get a general idea of Algarve's geology and biodiversity we can consider several ecosystems or habitats:
- Estuaries and lagoons
- Riparian corridors
- Woods and natural forests
To the west, until Ponta do Telheiro (Vila do Bispo), the cliffs comprise Palaezoic-grauvaques formations (300 million years) that, shaped by erosion over their considerable geological evolution, give rise to curious shapes. The top of the cliffs are flat, representing ancient wave cut platforms when this area was submerged below the average sea level approximately two million years ago.
On the southern coast, until Burgau, the cliffs are formed by more recent rocks (200 million years): marlstones and arenites. To the east the cliffs are carved out of carbonated rocks (biocalcarenites, with an abundance of marine fossils) of the Lower Miocene (16,5 to 24 million years), typically shaped by marine erosion over millions of years (carsificadas). Geoformations such as offshore stacks, potholes and caves are frequent.
Environmental conditions on the cliffs are extreme . The vegetation occurring on cliff faces is therefore well adapted to rocky soils and a dry and salty environment, where saline aerosols and strong ocean winds are constant. Typical of these habitats are species of the genus Limonium , as well as Mediterranean Beach Daisy, Sea Fennel and Goosefoot, which is also found in salty environments of the marshes.
The rocky faces of the cliffs, overlooking the sea and inaccessible to predators, are preferred resting, feeding and nesting places for a variety of birds. Birds found on the cliff faces are falcon (Peregrine Falcon and Kestrel) the Chough, Herring Gull and Swift. Isolated offshore stacks attract storks and cormorants. The numerous galleries and caves, typical of the carsified cliffs on the south coast are home to several species of cave roosting bats.
To the west on the Costa Vicentina we can find extraordinary fossil dune fields that extend inland from the cliff tops. These systems constitute a habitat of very high ecological and landscape value and contain plant species that are unique worldwide such as Avenula hackelli and Chaenorhinum lusitanicum. More recent and active dune fields are associated with river mouths, such as the beaches of Amoreira and Carrapateira. On the south coast and on the sandy sotavento the dune systems are dominant, with the exeption of the Meia Praia dune complex at Lagos, barlavento and with special emphasis on the sand barriers of the Ria Formosa.
Dune plants possess extraordinary adaptations that allow them to tolerate such extreme conditions that include being covered by shifting sands, strong winds, high levels of salinity and insolatrion and low levels of nutrients and water. As a consequence of the rapid changes in the conditions of this system from the beach to the interior of the dunes, the plants occur in a typical spacial sequence.
- At the high tide line pioneer species occur that are highly tolerant to salinity and uptake nutrients deposited by the tides, such as the Sea-rocket.
- The primary dunes form highly mobile chains parallel to the coastline. The dominant plant here is the Marram Grass, which maintains the dune structure with its long rhizomes. The sea daffodil and the prickly thrift are attractive plants occurring on these dunes.
- On the secondary dunes, more isolated from maritime exposure and with higher levels of humidity lo lying woody plants occur such as the aromatic curry plant.
Animal species that manage to survive in the dunes are primarily butterflies and snails, lizards, the eyed ocellated lizard and small mammals (mice and shrews). Some birds nest in the dunes such as the Little Tern, the Kentish Plover and the Common Tern.
Estuaries and Lagoons
Estuarine systems known as rias occupy a large area of the Algarve coastline. Outstanding examples are the Ria Formosa in the sotavento extending for 60 km and with 18.400 hectares of wetlands. In the barlavento region the Ria de Alvor is the wetland area of greatest importance.
The existence of sandy barriers and tidal dynamics give rise to the rias and their marshes. These ecosystems are amongst the most productive on the planet with large quantities of organic material deposited daily by the tides over the entire year. The marshes are considered the 'earth's kidneys', they retain water, filter out pollutants and recycle excess nutrients.
The dominant plants in these areas are adapted to the level of salinity in the water and in the soiland are distributed according to their tolerance and periods of submersion. Almost permanently submerged and in shallow waters is sea grass, a plant from the family of Zosteraceae. Spartina maritima also known as Cord grass, is found on the 'front-line' of the marsh, close to salt water. Progressively, in areas less subject to flooding by the tides, species of the genus Sarcocornia, Sea-rocket and Marisma-Negra can be observed. The last of these is restricted to the Algarvean coast.
The biological diversity of these systems is remarkable. The estuary functions as a refuge, feeding, growing and breeding area for many species of fish, molluscs and crustaceans thanks to the sheltered conditions and nutrient richness.
On the Algarve coast the avifauna also exploits these areas as excellent overwintering grounds, nesting grounds or as a stopover areas during migration between Europe and Africa. With over 30.000 birds, the Ria Formosa is the second most important overwintering wetland area in the country.
In the Algarve rivers and streams are small to medium sized with a temporary, torrential flow reime. They become entirely or partially dry during the summer. The dense vegetation along the river margins is fundamental for plants and animals that are restricted to to these types of habitat such as rhododendron and water lizard species, found only in the Monchique area of the Algarve. Riparian vegetation has a fundamental role in regulating river flow, abating the torrential character of the rivers and contributing to water storage during both the summer and the winter floods, resulting in a positive impact upon the water availability.
Amongst the dominant species most resistant to fluctuating water levels are Oleander and Tamarix which occur together with Brambles. The occurrence of the riparian forest galleries is rarer, restricted to more stable reaches with trees such as the Willow, Poplar, Common Ash and in the barlavento, the Alder. In some reaches introduced exotic cane species become dominant, reducing the ecological value of this habitat.
Fish fauna of note include the Allis Shad and Twaite Shad (migratory fish), or the Southern Barbel, the Guadian Nase and the Arch-mouthed Nase, the latter three species being endemic to the Iberian Peninsula, as well as the much sought after Eel and Lamprey. Another fish species of note is the Southwestern Nase, endemic to the Mira and the Arade watersheds, and the Saramugo, endemic to the Guadiana, is one of the world's most threatened fish species.
The most common bird species that depend on the riparian corridors are passeriformes, although birds of prey such as Bonelli's Eagle also occur. The otter is perhaps the most well known mamal found in the riparian corridors. The Mediterranean turtle and water snakes as well as salamanders are frequently observed inhabitants of these rivers.
Matos is the name given to shrub and scrub like vegetation and is the most abundantly occurring plant community found in the Algarve with forms shaped by the lack of water or comprising the remains of the understorey of original woods and forests. The history of deforestation (for agriculture, pasture and timber industry) together with the Cereal Campaigns of the first half of the 20th century drastically reduced the areas covered by natural scrubland and oak woodland (Quercus spp). Once turned over to the culture of cereals the soils were subject to erosion, but in the present day are now slowly regenerating and are mostly covered by low level scrub, mostly occurring in summer.
With the exception of localities such as Monchique the climatic conditions of the Algarve tend to be dry, with a long summer season with no rainfall. Whilst herbaceous plants reduce their life span to the humid season and persist in seed form during the summer, woody plants develop various adaptations in order to reduce water stress during the dry season, such as persisient, leathery, small leaves, protected by oils and varnishes. Known as aromatic plants they form a frequent part of the scrub community.
In the highland heaths on siliceous soils, the Rock Rose together with the spiny Gorse persist. On barrocal, on calcareous soils with rocky outcrops predominant plants include Rosemary, Thyme, Kermes Oak and the Dwarf Fan Palm, the only palm tree of European origin. It is possible to observe endemic plant communities with unique species in the Algarve, such as:
- The communities of the Sagres Peninsula with the Sagres Cistus (Cistus palhinhae) and South Gorse (Genista algarbiensis).
- The gorse stands of Sagres Gorse (Ulex erinaceus).
- The thyme stands of barrocal with Pólium (Teucrium lusitanicum) and Tomilho Cabeçudo (Thymus lotocephalus).
- The matos with Tojo-gatum (Stauracanthus boivinii) and Alcar-do-Algarve (Tuberaria major), between Faro and Quarteira.
The scrub community is home to medium sized furtive mammals such as the wild cat, the genet and the mongoose. The most frequently sighted mammals are probably the fox and the wild boar. As for easily identifiable birds (by song or sighting) are the Nightingale, the Bee-eater, the Hoopoe, the Blackbird and the Golden Oriole.
Woods and natural forests
The woods and natural forests, contrary to the produced scrublands, are formed by diverse species and have a complex, multistratified structure. The different species form a complex mosaic and occupy different strata: herbaceous, shrub and arboreal. This maximises ecosystem stability, supporting complex trophic pathways and greater biological diversity.
In the Mediterranean basin the natural climax forest (the most complex and stable stage of the ecosystem) comprises sclerophylic woods, mainly of species of the Quercus genus, such as the Holm Oak, the Cork Oak, the Common Oak and the Carrasco Oak.
The most common communities found in the Algarve have permanent leaves such as the Holm Oak stands (Quercus rotundifolia) and Cork Oak stands (Quercus suber), with some oak stands of Quercus faginea on more humid slopes. On the Serra de Monchique, a geological and climatic 'island', relict oak stands of Quercus canariensis can be found, although they are in risk of extinction and residual in character.
The medronhais are tall scrub stands dominated by Arbutus unedo and constitute the natural edge of these oak woodlands.
Other communities typical of the Algarve area are the Zambujeiro or wild olive woodlands (Olea europaea var. sylvestris) in the barrocal and the Juniper scrub stands (Juniperus turbinate) found on rocky siliceous soils (Monchique and Guadiana) or calcarious soils (barrocal and litoral) and also on sandy, coastal soils.
Wild and cultured pine woods on the sandy areas of the coastal strip, although used for timber production, are cosidered semi natural forests and are considered of of considerable ecological interest. The same can be said of orchards that are semi abandoned or subject to low levels of human intervention, species introduced centuries ago such as the Olive, Almond and the Carob tree.
The montados are a particular type of semi natural forest with a sparse arboreal layer and pastures in the lower layers, which has important ecological functions. Cork is the primary resource produced in the cork oak montados.
Forested areas constitute the last refuge in the Algarve for large birds of prey such as Bonelli's Eagle.
(Source: Associação Turismo do Algarve)