Encyclopedia of biodiversity encyclopedia of biodiversity, (7 volume set) ( PDFDrive ) 1688

Ecosystems of South America Luis Anibal Solorzano Cardenas, Gordon and Betty Moore Foundation, CA, USA r 2013 Elsevier Inc All rights reserved Glossary Caatinga Collective name assigned to the semiarid ecosystem of eastern South America Some authors use this term as a general name for a type of thin Amazonian forests In this article, however, the term is reserved for the xeric caatinga region of northeastern Brazil Cerrado Name assigned by phytogeographers to the tropical savannas of the central Brazilian shield Cerrado vegetation is further divided into four categories: (1) campo limpio (i.e., clean field), (2) campo sujo (i.e., dirty field or grasslands with scattered shrubs), (3) campo cerrado (i.e., closed fields or grasslands with numerous trees and shrubs), and (4) cerradao (i.e., when the vegetation is dominated by a closed canopy of trees) Chaco Region located between the Parana´ basin, the central Brazilian shield, and the Andes The ecosystems present in the Chaco region include temperate grasslands, savannas, and arid and semiarid environments Llanos Region of tropical South America, in the east side of the Andean range of Colombia and Venezuela The llanos landscapes occupy lower elevations (2–300 m), and the landforms vary from flat to rolling terrain The dominant Outline South America contains a diversity of ecosystems from tropical, subtropical, alpine, and temperate environments (Archibold, 1995) The geology, climate, and biogeographical history of the continent have important consequences in shaping the contemporary geographic distribution of ecosystem types and their structural attributes and functioning (Beard, 1955) The stability of the old Precambrian shields and the recent orogenic evolution of the Andean range have been the principal factors that determine geomorphologic, edaphic, and continental climatic patterns that correlate with the geographic distribution of major ecosystem types The lifting Andean range causes altitudinal zoning and different environments that have significantly increased the diversity of ecosystems that occur in the continent Most of the area of South America occupies tropical latitudes, hence tropical ecosystems dominate the landscapes The main tropical ecosystems include tropical rain forest, dry forest, cloud forest, savannas, shrub lands, xeric formations, and high Andean ecosystems (Archibold, 1995) Ecosystems of the southern temperate regions include temperate grasslands, the Mediterranean Matorral, and temperate forest and deserts There are extensive wetland ecosystems across the continent occupying areas along the floodplains of major rivers, lakes, estuarine Encyclopedia of Biodiversity, Volume vegetation is savanna with areas of dry forest, gallery forest, and morichales Mangal/mangle Name assigned to the vegetation of mangrove ecosystems Pampa(s) Region of temperate South America, west of the Andes in Argentina The Pampa region contains several ecosystem types, including temperate grasslands, dry forest, and xeric shrub lands Pantanal Largest wetland of South America drained by the Paraguay River and its tributaries Paramo Ecosystem of the high Neotropical mountains, found in South America above tree line in the northern Andean mountains of Colombia, Venezuela, Ecuador, Peru, and Bolivia The dominant vegetation is similar to an alpine meadow or grassland; cacti and giant-rosette plants are conspicuous Puna Ecosystem of the high Andean mountains found above tree line from Bolivia to southern Peru The Puna comprises of four distinct ecological regions: wet, dry, thorny, and desert Puna The dominant vegetation types vary from grassland/shrub lands to desert Varzea Floodplain of the whitewater rivers of the Amazon basin areas, and seasonally flooded savannas Mangrove ecosystems occur along the tropical coastlines of both the Atlantic and Pacific oceans Physical Environment South America occupies an area of approximately 18 million square kilometers and extends from about 111 N to 561 S, and from about 351 W to 811 W The continent has been connected to Central and North America by the land bridge of the Panamanian Isthmus for approximately 3.5 million years and is bounded on the east by the Pacific Ocean, on the north by the Caribbean Sea, and on the west by the Atlantic Ocean Geology and Geomorphology The geological history of South America cannot be fully covered in this summary as it is very complex and reflects many tectonic and orogenic processes operating over millions of years However, the structural characteristics of South American ecosystems – in particular the development, properties, and geography of their soils – are significantly associated with the geophysical environment Likewise, the major landforms http://dx.doi.org/10.1016/B978-0-12-384719-5.00276-8 105