Geography of the archipelagos
Geographically, the Autonomous Community of the Balearic Islands is made up of a group of islands divided into two distinct archipelagos: Mallorca and Menorca make up the archipelago of the Gymnésies ("Greater Balearics"), while Ibiza and Formentera together form the archipelago of the Pitiüses ("Lesser Balearics"), which in Catalan means "pine-covered", in reference to the primeval pine forests that cover their territories. The four main Balearic islands - Mallorca, Menorca, Ibiza and Formentera - have a total surface area of almost 5,000 km².
Mallorca is the largest island in the community, measuring 100 km from east to west and 80 km from north to south, with a surface area of 3,640 km². It is the island with the greatest variety of landscapes, with sandy and rocky coasts, but above all two mountain ranges whose peaks climb to over 1,400 m in the Serra de Tramuntana, culminating in the aptly named Puig Major (1,445 m). Between the two sierras lies a vast depression housing the island's main, albeit modest, settlements. The rest of the area is given over to agriculture, particularly fruit growing (orange, lemon, fig, etc.). The other large island in the northern archipelago, Menorca (695 km²), is almost six times smaller than its imposing neighbor, but is still the second largest island in the autonomous community. Approximately 48 km long and 20 km at its widest, it is extremely windy and crossed by low walls that give it its charm. With its modest vegetation cover, Menorca is dominated by a similarly modest peak, Monte Toro, which rises to 357m. The island has two major urban centers, Maó to the east and Ciutadella to the west, home to two-thirds of the population. Surrounding Mallorca and Menorca are a series of smaller islands, the most important of which are Sa Dragonera and Cabrera, to the west and south of Mallorca respectively.
The second archipelago of the Autonomous Community is the Pitiüses or Pityusas, made up mainly of the islands of Ibiza and Formentera. Ibiza is the third-largest Balearic island, covering 570 km². 40 km long and 20 km wide, it is extremely mountainous, and in some places is still covered by a primeval forest of pines, the trees that gave the archipelago its name. There are rare plains, dominated by Mount Sa Talaiassa, 475 m high. Other mountain ranges, mainly composed of limestone dating from the Cretaceous period, include the 347 m-high Serra dels Mussols, the 398 m-high Serra Grossa and the 410 m-high Mala Costa. Ibiza is joined to its neighbor Formentera by a series of rocks and islets. The two islands are separated by a 3 km strait dotted with islets, classified as a nature reserve (the Strait of Es Freus). This is the second most important marine reserve in Spain, named Parc naturel de Ses Salines. It is renowned for the richness of its seabed, home to the posidonia meadows, a Unesco World Heritage site since 1999. Formentera (83 km² and 69 km of coastline) resembles Guadeloupe in shape and is known as the smallest of the Balearic islands, but it is also the flattest and driest. It is made up of two distinct parts, one very flat to the west, and the other mountainous to the east, dominated by the 192-meter Puig La Mola, the island's highest peak. The two extremities of Formentera are linked by a narrow strip of land bordered by beaches. To the south of the island, Cap de Barbaria forms an arid, semi-desert promontory dominated by a lighthouse that serves as a landmark for ships entering the Mediterranean Sea via the Strait of Gibraltar, while to the east, the La Mola plateau reveals windswept rural landscapes that end in sheer cliffs. The east coast is also indented with several points, from Punta de sa Creu in the north to Punta Roja in the south.
The Posidonia meadow: a treasure of the seabed
Posidonia oceanica is not a seaweed, but a flowering plant that adapted from a terrestrial to an oceanic environment nearly 100 million years ago. Endemic to the Mediterranean, they form what are known as Posidonia "meadows" or "seagrass beds". Considered true "ecosystem engineers", they play an essential ecological role on the Mediterranean coast. Although they cover a large part of the Mediterranean, the Posidonia meadows concentrated in the Ses Salines Nature Reserve, between Ibiza and Formentera, are among the best preserved.
The plant consists of roots buried in the sediment and upright stems, both called rhizomes. These are veritable stores of nutrients! The upright rhizomes produce scale-like leaves all year round. These leaves are a refuge for many plant and animal species, which find a natural habitat in these meadows. When they fall, the leaves produce a large mass of plant matter, which is essential to the diet of many animal species: carried by the current, they serve as food for sea urchins, crustaceans, certain fish and even sea turtles. In autumn, the plant begins to flower (though not necessarily every year, depending on water temperature), producing a sometimes very dark, olive-like fruit after about eight months of ripening, earning it the nickname "sea olive" in some parts of the Mediterranean.
An important source of oxygen. A veritable "lung of the sea", Posidonia oceanica is a major source of oxygen to the water, helping to maintain the biodiversity of its ecosystem. It is said that one square metre of Posidonia produces more oxygen than one square metre of Amazon rainforest! Posidonia also plays a purifying role, trapping fine particles of sediment in the water. Stored in what is known as the "matte", the sediment contributes to the growth of Posidonia rhizomes. Thanks to this mechanism, the plant in turn contributes to water transparency. What's more, the presence of Posidonia meadows slows down hydrodynamics, and consequently limits the presence of suspended particles in the water, favored by the various marine currents.
A protected species. Posidonia meadows have been in decline for many years. The development of construction along coastlines, the discharge of harmful chemical substances into the sea and uncontrolled fishing in sensitive areas have long favored the regression of this natural regulator of the Mediterranean seabed. Today, posidonia meadows are protected, as are the meadows off Ibiza and Formentera: the Ses Salines reserve was declared a UNESCO World Heritage Site in 1999. Today, posidonia is under particular scrutiny throughout the Mediterranean basin for its valuable ecological virtues.
