Chile’s Natural Regions: 15 Unique Ecological Zones

Natural Regions of Chile

Various classifications of the natural regions have realized the special territory of Chile. One of the most accepted and used is that of Di Castri (1968), who, based on a set of criteria, which included aspects of the physical and biological environment, provides a total of fifteen ecological regions that respond to different features within the ordered climate trends: desert, tropical, Mediterranean, oceanic, continental, and polar.

These regions are:

Easter Island must be treated to a warm oceanic regime, not represented on the mainland. The archipelago of Juan Fernandez has partnerships with a humid Mediterranean climate regime equivalent to central-southern China, and Antarctica should be included in a system of polar and subpolar.

A. Desert Area Trend

The desert region of Chile is characterized as an area with an almost complete absence of rainfall.

1. Landlocked Desert Region

A period of dryness throughout the year, no cold weather, more marked biological activity in winter (in the southern part of this region), relative humidity above 75%, and highly variable rainfall on average ranging from 0 to 15 mm characterize this region. The vegetation physiognomy is mainly that of a semi-desert, with cacti and winter annuals of activity, seated on red soils with saline desert folds, much more developed than in the interior.

2. Inland Desert Region

This region is arid yet twelve months, with a relative humidity that hovers around 50% and a low average rainfall (between 0 and 10 mm per year). The vegetation is almost completely missing in most of this area, except in some valleys and in places where it is concentrated more moisture in soils with relatively shallow water tables are located mesquite savannas (Prosopis mesquite).

B. Tropical Trend Zone

The tropical areas of influence in Chile are limited to regions of high and Pre-Andean band against the internal deserts; bioclimatic differentiation summer rains are continuing in the first. The other condition of the tropical climate, temperatures are rather high, is almost zero by the effect of altitude.

1. Marginal Tropical Region

This region is characterized by summer rains and high biological activity in January and February. The rainfall reaches values between 50 and 100 mm per year. Outside the red desert soils, brown soils are well developed. The vegetation physiognomy is that of a semi-desert with chamaephytes higrófilos gender and shrubs Baccharis Tessaria and along small streams, dense grasses and shrubs of the genus Cortaderia.

2. Tropical Andean Region

In this arid area is reduced to 7-10 months, showing vegetative activity between January and February. From 9-10 months average temperatures are below 10 ° C. Rainfall moves between 100 to 200 mm per year, on average, may in some areas of puna reach 300 to 400 mm. Soils are mainly lithosols, regosols and gray desert soils.

There are tolar plant formations, which are shrub steppes, usually on the stone floor. The vegetation is discontinuous, but sometimes quite dense. True is the Andean steppe grassland, where there is a dominance of grasses (Stipa and Festuca), these formations are the most dense and continuous. The llaretal consists mostly woody and evergreen species (Laretia and Azorella), representing the only fuel in the area, use has dramatically reduced the amount of existing vegetation.

C. Mediterranean Area Trend

The Mediterranean climate can be characterized primarily by the presence of rain during winter and variable periods of drought in summer. This area, which is one of the most extensive in Canada, is degraded to the northern desert and southward trend in the oceanic region. It is an area that shows large interannual variations in rainfall amounts (Fuentes et al. 1988).

It is possible to distinguish six regions within the Mediterranean trend in Chile.

1. Mediterranean Region Perarid

The characteristics of the arid show a clear gradient from the coast inland (eleven months in the arid interior and nine, respectively, on the coast and part pre-Andean). The average relative humidity is 25% and rainfall of 25 mm. The soils are red desert, sometimes profound, and along the coast or reddish-brown soils are more developed compared to the interior. The dominant vegetation is semi-desert, with cacti that increase their density to the south. In the coastal valleys are cacti and along the rivers there are chañares.

2. Arid Mediterranean Region

This region is characterized by the features more clearly Mediterranean, and the marked decrease of the influence desert. There is no cold period, three or four months in winter subhumid. The dry period of 8-9 months is reduced to dry. Limiting climate, rather than aridity, is conditioned by the variation from year to year rainfall, with rain alternating dry years. Soils in this region belong to the brown limestone. The area of highland Talinay (where there are relict forests of fog), brown forest soils are typical.

The vegetation physiognomy is heterogeneous, there are semi-deserts, or even absolute desert caused by overgrazing of goats to hygrophilous temperate forests, due to the fog, in the Coastal Range, clearing native vegetation has been transformed into bushes grazing excessive and crop growth can only seasonal herbaceous associations. Inside is dense thorn scrub, but most of this area is just an impoverished steppe. A particular aspect is the existence of hygrophilous temperate forests, as Fray Jorge and Talinay (See: Fray Jorge National Park). It has been ascertained that uptake into the cloud forest of Fray Jorge is equivalent to about 1,000 mm per year, which is similar to the precipitation that falls to the south (36-37 ° S), where forest vegetation persists hygrophilous tempered.

3. Semiarid and Subhumid Mediterranean Regions

The rainfall of this zone is between 330 and 700 mm per year. The soils are described as brown limestone, except in the Andes foothills, where there are brown forest soils.

In relation to vegetation, there are shrub steppes in the coastal terraces, sparse sclerophyll forests in the Cordillera de la Costa, savanna with Acacia caven (Hawthorn) in the central depression (an area located between the Andes and the Cordillera de la Costa), open sclerophyll forest and thorn scrub in the Pre-Andean zone. In the coastal range forests hygrophilous there, where fog or shallow groundwater permit, such as palm trees and small groups of Nothofagus obliqua (oaks).

The differences among the semiarid and subhumid occur in the sense of a growing extension of forest formations and a decrease of cacti to the south. Extreme differences in vegetation and wildlife as the exposure of the slopes are typical in this region. In the southern territories of these regions are often observed fairly dense forest, and north, and even semi-desert thorn scrub with Puya and Trichocereus (Echinopsis currently appointed). Since the Acacia caven savanna, sclerophyllous forests are successive formations hygrophilous mixed with cinnamon and oak, and pure deciduous Nothofagus forests.

4. Humid Mediterranean Region

This region is characterized by a more prolonged wet period, with a consequent reduction of drought. The rainfall is from 1,000 to 1,300 mm in the north and south, respectively.

Soils mostly belong to the group that the transition is defined as brown to reddish-brown laterite. There are also volcanic soils, which are succeeded by brown forest soils. Referring to the plant physiognomy, there are differences in vegetation with that of the central region and vegetation belts of both sides of ridges, oriented to the north.

In the northern part of the central plain there is a final penetration of Acacia caven (thorny), but near the Laja River, is a forest-park, which increases its density along the rivers. The forests are mixed: there are Mediterranean-type species like peumos (Cryptocarya alba), quillayes (Quillaja saponaria), mixed with typical species Valdivia (Nothofagus, Drimys, cinnamon), which increases towards the south. In the Andean region are coniferous forests. The southern part of the region (Malleco River area) is where the highest percentage of eroded due to deforestation, cultivation of wheat without rotation and other reasons. The appearance of the area has been modified by numerous plantations of Pinus radiata (Monterey pine).

5. Mediterranean Region Perhumid

Annual rainfall in this region reaches 1,400 mm and in some months the average temperature has values below 10 ° C. There are some areas (near the cities of Osorno and Rio Bueno, latitude 40-41 ° S) in which under conditions of greater environmental dryness due to Coastal range that is high and produces a shadow effect of rainwater into the interior. That makes them different from the general conditions prevailing in this region.

The floors are the type trumaos and brown forest. On the one domain plant physiognomy Valdivian forest and along the coast are forests transition to the region before. In height Nahuelbuta mountain range, and the Andes, are forests of monkey puzzle (Araucaria araucana) with coigüe, and, above, Andean steppes.

D. Oceanic Trend Area

This area includes the entire southern mainland Chile, from the southern edge of the Mediterranean to Patagonia, Tierra del Fuego, Navarino Island, and Cape Horn. In this area there is a gradual increase toward the south, the cold, persistent winds, and as to soils, the difficulty of drainage, with the exception of some Patagonian steppes. The height of the Andean chain has declined steadily to the south of parallel 41 ° S.

1. Oceanic Region with Mediterranean Influence

It begins south of Temuco (approximately latitude 39 ° S), ending just south of the island of Chiloe. Rainfall decreases sharply in summer, with three to four months subhumid, and some dry conditions. The average rainfall reaches values between 2,000 and 2,500 mm annually. In relation to soils, there are three main formations: reddish-brown laterite to the coast, trumaos (soils derived from volcanic ash) in the central and pre-Andean podzol in much of the Andes and the western part of Chiloe.

The vegetation here is more homogeneous than in previous zones. Domain Valdivian forest, although it takes several names:

• a. – Selva valdiviana coastal hygrophilous and mesothermal more exposed to flooding, with dense clusters of Chusquea (isopropyl), mosses, and ferns.
• b. – Selva valdiviana Andean Microtherms, with a smaller herbaceous.
• c. – Forest of Chiloe, where it dominates the coigüe, partnerships with cinnamon, and formations of oak and laurel, less dense in the central depression. At higher altitudes are coniferous forests, and larch woods.

2. Cold-temperate Oceanic Region

It includes most of the Andes, in the Aysen region (approx. 44-45 ° S). There are two main regions: the archipelago and the mainland. Rainfall (average 2500 to 3000 mm per year in some areas up to 7,000 mm) are well distributed throughout the year but are sometimes excessive, and there are problems with runoff. In some locations the decrease in summer rainfall. The soils are of a brown podzolic and peat lands are in areas wetter drainage difficulties.

The vegetation is still Valdivian forest type. There are conifer and cypress Guaitecas. In most of the archipelago’s forest is replaced by marshy areas, a dense ericaceous vegetation, sedges, rushes, grasses, and ferns. Some species of coigüe cinnamon and states are reduced to shrub. This is a transition region between Valdivia and Magellanic forests.

3. Subantarctic Ocean Region

Represented mainly by Magallanes, corresponds to the so-called Magellanic tundra. As for the climatic, polar influences are expressed in very low temperatures. There are strong winds and persistent rain and an excess of poor drainage. For eight to twelve months the average temperature is below 12 ° C, of these, three or four down to 5 ° C. The average annual rainfall reaches to 3,550 mm. The peat soils are podzols and are found in forest areas. The predominant vegetation is the marshy tundra plants in thickets. There are rushes and sedges. In better-drained areas are shrub and forest formations, practically the same as in the Magellanic forest.

4. Oceanic Trans-Andean Region

The main condition of this region is the gradual decrease of rainfall towards the east, as the influences of the west coast are reduced. The aridity reappears in this region, increasing the temperature in summer. The duration of the drought is variable semiarid in three months to Punta Arenas and Chile Chico. The cold period is also variable: five to ten months as average temperatures below 10 ° C and of these three to five months with average temperatures below 5 ° C.

It is the only area in Chile, except for the Andean region, where the average minimum is close to 0 ° C. The strong winds increase the effect of cold and aridity. The climate is defined on a set of several trends: oceanic influences from the west, continental influences weaker east and south polar influences. The values show annual rainfall between 1,220 mm and 1,900 mm. To the east, the average temperature, maximum and average, increase minimum temperatures, rainfall and relative humidity decreases. Higher temperatures, rainfall and humidity are lowest for the town of Chile Chico, on the shores of Lake General Carrera. In the steppe zone the annual rainfall is less than 500 mm.

The north face plant sample (Aysen region) the presence of transition forests, jungle-like valdiviana. Further south, there Magellanic forest. The rapidly degraded forest to the Patagonian steppe, which is the most extensive training in this region. This resembles the grassland steppe

E. Continental trend Area

There is no area in the country a distinctly continental, due to the narrowness of the territory between the sea and the Andean chain. However, continental influences are clear in some areas of the country: central territories east of the Cordillera de la Costa in southern trans-Andean areas, particularly in the Andes.

1. Andean Region

This region includes the territories of the Chilean Andes for areas between the edge of the eternal snow line and trees. The climatic characteristics of this region show that compared to the Mediterranean region is high Andean localities, which show the typical concentration of rainfall in winter, others have irregularly distributed rains during the year, and even top two in winter and summer. Finally, towards the north of this region, there is a large concentration of rain in the summer, by the penetration of tropical trends.

The show features plant grass steppes and tundra, there are similarities to the high tropical region and the Patagonian steppes and grass in grassland (Stipa, Festuca) are the coironales, as well as small bushes and Adesmia Fabiana. The most common trees Andean steppes are conifers.

Source:

“Ecological Regions of Chile”
Reference: Hajek ER 1991. Environment in Chile. “The environmental situation in Latin America.” CIEDLA. Buenos Aires: pp. 237-294.
Compilation: Professor Online

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