Habitats are naturally variable throughtout the region, depending on factors such as soil types, rainfall and altitude, but inevitably the greatest influence has been that of man. Over many centuries much of the region has been systematically cultivated and modified to meet human needs and to satisfy our demands, so today little remains of the original habitat, which in the main would have been a vast Mediterranean forest.
Throughout this mainly hot and seasonally dry region, woodlands are predominantly made up of evergreen tree species. By far the most important, and presently the largest unbroken areas of remaining woodlands, are the beautiful Cork Oak woodlands of Los Alcornacales, but there are also areas of Pine forest, such as el Pinar del Rey at San Roque and more fragmented areas along the coast at Tarifa.
Where woodland has been removed, derived vegetation types in part replace it, alongside habitations, increasingly large areas of cultivation, groves and orchards. Of these derived types, two, those of maquis and garrigue are particularly important as wildlife habitats
This habitat is made up of dense, evergreen small trees and shrubs, usually reaching 1-3m in height, sometimes more. It often occurs where the true forest has been previously destroyed, sometimes where just the larger trees have been removed. throughout the Mediterranean area, dense maquis is especially well developed along coasts facing west or south-west, usually reaching from sea-level up to altitudes of 600m, but it may occur at heights of up to 1000m or even higher. Maquis can recover from burning, provided the area is not subsequently cleared by man or heavily grazed. Several plants typical of maquis, such as Arbustus unedo, the Strawberry Tree and Erica arborea, the Tree Heather have remarkable powers to rejuvenate; if the top of the plants are destroyed by fire, new growth will sprout from the base of the plant.
This is a more open community of dwarf evergreen shrubs, seldom reaching more than 0.5m in height. Garrigue is very widespread throughout the Mediterranean area and is characterised by many aromatic small shrubs that are colourful in flower. It is more open than maquis, allowing a great variety of smaller herbs to associate with the shrubs, and it is richer in annuals, orchids and bulbs.
Maquis and garrigue are general terms used to characterise vegetation types; in reality there are many intermediates between the two types. Bush communities of these types, which are commonn along the coast and the hills and lower mountains are maintained by a number of elements. Grazing by livestock, especially sheep and goats, cutting of the large trees and bushes for fuel and charcoal, clearance for cultivation, (particularly for olive and citrus groves) and fires, be they natural or man-induced to clear land for grazing, all contribute to preventing large evergreen trees re-establishing and to promote the dwarf shrub communities.
Degeneration of maquis ultimately results in garrigue. At the same time, abandoned pastures, citrus or olive groves will eventually become colonised by dwarf evergreen shrubs and also revert to garrigue. This cycle of degeneration and regeneration is typical of large parts of the Mediterranean region.