Misplaced Pages

#853146

26-630: The Arid Diagonal acts to isolate the temperate and subtropical forests of Chile and southern Argentina from other forests of South America. Together with the Quaternary glaciations in the Southern Andes , the diagonal has controlled the distribution of vegetation throughout Chile and Argentina . The concept of a South American Arid Diagonal was first coined by French geographer Emmanuel de Martonne in his 1935 work Problème des régions arides Sud-Américaines . However, few works dealing with

52-965: Is 6 °C (43 °F) at 55°S. On the eastern side of the mountains the temperature variations are much more severe and there is a more continental climate . Much of the soils around the Andes are derived from volcanic material. In this soils weathering has produced water-retentive allophane that can allow the vegetation to withstand drought. These soils develop chiefly from volcanic ash and wind-redeposited ash deposits that can reach several meters in height. These kind of soils have high porosity and low bulk density . Locally they are known as trumao which are Andosols . Other soil types include ñadis which are aquepts usually developed on top of glacifluvial material . While trumaos originate from recent ashes on ancient ashes brown and red-clay soils develop, these soils are not restricted to old ash parent material but do also originate from metamorphic rocks in

78-453: Is also found here. This region lies in the centre of the forest to the west of Neuquén . The dominant species here is the Chilean pine ( Araucaria araucana ). This area has been the location of much logging in the past. The understorey is scanty and consists of such shrubs as the bamboo caña coligüe ( Chusquea culeou ) and the box-leaved barberry ( Berberis buxifolia ). The fauna of

104-570: Is culturally significant because of its archaeological and historical value. The Andean Patagonian forest region is located between 37°S and 55°S latitude, and clothes both sides of the Cordillera. The forest extends for about 2,200 kilometres (1,400 mi) parallel to the Pacific coast, extending from just south of Mendoza in Argentina to the southern end of Santa Cruz Province and to

130-486: Is divided into four regions; deciduous forest, Magellan forest, Valdivia forest and Del Pehuén. Rainfall is more plentiful in the Andean area than in other parts of Patagonia and there are several lakes, reservoirs and hydro-electric projects within the forested area. There is also an increase in population in nearby urban areas and greater tourism in the forest, resulting in increasing pollution. The climate of these forests

156-584: Is governed by atmospheric, topographical and oceanic factors. The prevailing westerly winds are laden with moisture and come from the Pacific Ocean, being linked to the South Pacific subtropical anticyclone . Frontal systems move inland and precipitation is high at low altitudes in southern Patagonia, making the fiord region one of the wettest places on earth outside the tropics, with rainfall topping 7,000 mm (276 in) per year in places. To

182-513: Is influenced by humid air masses moving in from the Pacific Ocean which lose most of their moisture as they rise over the Andes . The flora is dominated by trees, usually of the genus Nothofagus . The Bosque Andino Patagónico represents one of the few relatively undisturbed temperate forests that has been little changed by man. It occupies approximately 6.5 million hectares of land. It

208-410: Is some figurative art showing humans and animals and the colour most often used is different shades of red. The style of the work makes it likely to have been performed by hunter-gatherers in the late Holocene era. South Pacific High The South Pacific High is a semi-permanent subtropical anticyclone located in the southeast Pacific Ocean . The area of high atmospheric pressure and

234-730: The Atlantic coast of Patagonia. The Arid Diagonal has existed since the Neogene . The origin of the aridity of the northern part of the diagonal is linked to two geologic events: a) the rise of the Andes — an event that led to the permanent block of both the westward flow of moisture along the tropics, and the eastward flow of moisture in Patagonia and b) the permanent intrusion of cold Antarctic waters (the Humboldt Current ) along South America's west coast. Together with

260-602: The Central Andes and the South Pacific High . To the south in the westerlies , the rain shadow that the Southern Andes cast over eastern Patagonia similarly blocks moisture. South of Mendoza (32°53' S), the driest parts of the diagonal move away from the Andes as the mountains lose height, causing some humidity to penetrate; thus, at more southern latitudes the driest parts of the diagonal lie on

286-537: The Chilean Coast Range . In the high Andes, the soils are known as lithosols and contain little organic matter. Much of the ground here may be subject to permafrost and the vegetation is scant, with mosses and lichens growing on the rocks and scree. Generally speaking soils in the northern Argentine area are arranged in the following pattern by decreasing longitude and altitude lithosols, andosols , cambisols and regosols . The last ones occur at

SECTION 10

#1732773181854

312-425: The Quaternary glaciations in the Southern Andes, the diagonal controls the distribution of the vegetation types over Chile and Argentina. Bosque Andino Patag%C3%B3nico Bosque Andino Patagónico , also known as Patagonian Andean forest , is a type of temperate to cold forest located in western Patagonia in Argentina and also in southern Chile , at the southern end of South America . The climate here

338-471: The hardy fuchsia ( Fuchsia magellanica ), reeds and ferns. Mammals present in the Valdivian forest include an arboreal marsupial , the monito del monte ( Dromiciops gliroides ), the world's smallest deer, the southern pudú ( Pudu puda ), and South America's smallest cat, the kodkod ( Leopardus guigna ). The giant snail ( Macrocyclis peruvianus ), with a shell length of 6.5 cm (2.6 in),

364-841: The large four-eyed frog ( Pleurodema bufoninum ), Pleurodema bibroni and the Darwin's frog ( Rhinoderma darwinii ), and there are also numerous lizards and the Peru slender snake ( Tachymenis peruviana ). There are many species of native fish in the lakes and rivers. Rock paintings have been found in the valley of the Rio Manso in north Patagonia, both in Argentina and in Chile. The paintings are largely abstract and mostly consist of complex patterns of straight lines, with zig-zag lines, diamonds and triangles, and sometimes concentric circles. There

390-403: The radal ( Lomatia hirsuta ), the raulí beech ( Nothofagus alpina ) and the roble beech ( Nothofagus obliqua ). Underneath these large trees there is usually a lower layer which includes such shrubs and small trees as boxleaf azara ( Azara microphylla ), Chilean wineberry ( Aristotelia chilensis ), Darwin's barberry ( Berberis darwinii , box-leaved barberry ( Berberis microphylla ) and

416-413: The south Andean deer ( Hippocamelus bisulcus ) and numerous species of rodents. There is a wide range of bird life, ranging from the black-chested buzzard-eagle ( Geranoaetus melanoleucus ) and Magellanic woodpecker ( Campephilus magellanicus ) to the Chilean swallow ( Tachycineta meyeni ) and the torrent duck ( Merganetta armata ). Amphibians are represented by the toad ( Rhinella spinulosa ),

442-608: The Andean Patagonian forest region is very varied with many endemic species. Predatory mammals include the puma ( Puma concolor ), the culpeo ( Lycalopex culpaeus ), the southern river otter ( Lontra provocax ) and the Geoffroy's cat ( Leopardus geoffroyi ). Other mammals include Humboldt's hog-nosed skunk ( Conepatus humboldtii ), the Patagonian mara ( Dolichotis patagonum ), the guanaco ( Lama guanicoe ),

468-473: The Arid Diagonal mention this foundational text. The original Arid Diagonal of de Martonne went from Antofagasta in northern Chile to the northern coast of Argentine Patagonia . However, other authors like Margarita González Loyarte (1995) later extended it to the coast of northern Peru. The northern portion of the Arid Diagonal is a result of the blocking of the trade winds by the barrier formed by

494-456: The absence of bamboo. There are also peat bogs with various species of sphagnum moss and plants such as the sundew ( Drosera uniflora ). The Valdivian forest lies in a discontinuous belt on the west of the area. The precipitation is greater here. Some parts, such as at Puerto Blest near the Rio Negro ( Argentina ), have an average rainfall of 4,000 mm (157 in) per year, and

520-419: The air is no longer moist and little rain falls at any time of year. Over a west-east distance of 80 kilometres (50 mi), precipitation can fall from 2,000 mm (79 in) per year to 200 mm (8 in). On the western side of the Andes, the cold Humboldt Current and prevailing westerly winds help to reduce temperature variations and the mean air temperature is 12 °C (54 °F) at 36°S and

546-425: The bamboo coligüe cane ( Chusquea culeou ), as well as a wide range of herbs. The southern end of the forest is characterised by a colder, dry climate and the number of species growing here are more limited. The predominant tree is the evergreen Magellan's beech ( Nothofagus betuloides ), sometimes accompanied by the canelo ( Drimys winteri ). The understorey shrubs are similar to the deciduous forest apart from

SECTION 20

#1732773181854

572-478: The boundary with the Patagonian steppe . This is the easternmost and driest part of the forest and extends from Neuquén to Tierra del Fuego . The three main species here are all deciduous, the lenga beech ( Nothofagus pumilio ), the Antarctic beech ( Nothofagus antarctica ), which is found typically in lower and damp locations, and the mountain cypress ( Austrocedrus chilensis ). Other species present are

598-480: The east of the Andes precipitation declines to nearly nil. In northern Patagonia, the seasons vary as the anticyclone oscillates northwards in summer and southwards in winter. More frontal systems cross the coast during the winter and that is the season when most precipitation occurs on the western slopes of the mountains. Some places suffer prolonged droughts in summer, and further east, on the Patagonian plateau,

624-467: The impression is of jungle. Here the most common trees are the coihue ( Nothofagus dombeyi ), the Patagonian cypress ( Fitzroya cupressoides ), the Chilean hazel ( Gevuina avellana ), the ulmo ( Eucryphia cordifolia ), the Guaitecas cypress ( Pilgerodendron uviferum ), the podocarp ( Podocarpus nubigenus ) and the female maniu ( Saxegothaea conspicua ). There is a dense understorey of bamboos,

650-561: The island portion of the province of Tierra del Fuego . It is a narrow strip of land, with a maximum width of 75 km (47 mi), dwindling to zero in places near the Chubut River and Santa Cruz Province. It is bounded to the east by the Patagonian Desert . Ecologically the forest have no equivalent in the northern hemisphere . This is indebted to distinct biota histories and environmental differences. The forest

676-478: The presence of the Humboldt Current in the underlying ocean make the west coast of Peru and northern Chile extremely arid. The Sechura and Atacama deserts , as the whole climate of Chile , are heavily influenced by this semi-permanent high-pressure area. This high-pressure system plays a major role in the El Niño–Southern Oscillation (ENSO), and it is also a major source of trade winds across

#853146