La Mancha

Abstract

The phytogeographic sector of La Mancha is located in central-eastern Spain and encompasses the vast plateau of La Mancha and the peripheral areas of transition to the surrounding mountain ranges. Sedimentary rocks (marls, limestone and gypsum) and base-rich soils are predominant. The climate is prevalently dry mesomediterranean with continental traits. The sector is divided in four watersheds: the Tagus and Guadiana basins drain water into the Atlantic Ocean, while the Jucar and Segura basins drain into the Mediterranean Sea. On well drained soils the main vegetation types are: (a) forests and sclerophyllous woodlands dominated by Quercus rotundifolia, Quercus coccifera, Pinus halepensis, Juniperus phoenicea and in a much lesser extent Quercus faginea or Juniperus thurifera, all of them currently very fragmented in their occurrence due to human deforestation, which has been particularly intense on the plateau; (b) a calcicole scrub often dominated by thorny or cushion like gorses, a gypsum scrub rich in gypsophytes, and yellow retama broom fields; (c) dry grasslands, including the tall steppic grasslands of Macrochloa tenacissima and in part Lygeum spartum, the short grasslands of Brachypodium retusum, the mesophilous grasslands dominated by Brachypodium phoenicoides, the heavily grazed pastures with Poa bulbosa, and the annual ephemeral pastures. Riparian ecosystems include elm, poplar, willow and tamarisk forests, in general poorly conserved, as well as some types of meadows. Instead, wetlands are abundant and varied (permanent lakes, some of them of karstic origin, fluvial floodplains, salt marshes and temporary ponds) due to the flat topography that favors the formation on endorheic basins and the large deposits of groundwater. Wetlands with fresh and subsaline water shelter large stands of reedbeds, fen-sedge beds and aquatic vegetation. Salt marshes are populated by many special communities: succulent annuals, salt scrub of woody succulents, salt steppes of Lygeum spartum and Limonium spp., saline rush meadows, aquatic halophytes, tamarisk woodlands, etc. Some comments about land use and conservation concerns are also given, highlighting the historically intense human pressure on the territory.