Gringo Guide : Chile Ecology : Flora

Chile Ecology : Flora

Chile is home to a wide variety of floral species thanks to the diversity of its geography and climate, and distributions are correlated strongly to rainfall. Chilean flora has adapted to a wide variety of environmental extremes, from northern cacti deserts to central mediterranean woodlands and southern temperate rainforests of the Valdivian ecoregion, that results in a wealth of diversity and variation.

The flora in Chile is very distinctive compared to the flora of other countries. It is not so much the quantity of plant species ? it is estimated that Chile has only about 5,000 to 6,000 different species, which makes it look poor compared to some continental counterparts in tropical regions - but the adaptability, uniqueness, and usefulness of Chilean plants makes them stand out on their own.

The Chilean flora is of special note because of its geographic isolation. Chile is separated from the rest of the continental landmass by the high mountain range of the Andes along its length, very dry deserts in the north and forzen ice-fields in the south which makes migration and expansion of individuals and populations into and out-of the region extremely difficult. That means that Chile has probably the largest number, in percentage terms, of endemic plants in the continent. For example, the Alstroemeria genus, an exclusively South American plant family, has about 100 species, of which 49 grow in Chile; of these about 40 are endemic and not found anywhere else in the world in wild conditions (for comparison Argentina, Bolivia, and Peru have only one endemic species each!). There are thousands of plants which grow only in Chile, or, at best, a few areas of Argentina as well. According to one study, out of 5,082 named Chilean species, 2,561 - over 50% - are endemic.

Of particular note are the incredible diversity of cacti species, found along the Pacific coastline of northern Chile and the surrounding desert and adapted to live in these extreme weather conditions. Several genera are present here, with beautiful examples of Eulychnia, Eriosyce, Neoporteria and others. But Chile is well known by most cacti enthusiasts for one particular cacti genus, which is restricted to this country: the Copiapoas. These wonderful plants thrive mostly along the Pacific coastline of the Atacama and Antofagasta regions, and some of them are highly restricted to very few hidden valleys. [Specialist cacti tours are available, please contact us direct for information. Tours run in January and February.]

Also of note are Chile's temperate rainforests, which represent a biological 'hot-spot' of global conservation importance according to Conservation International and the World Wildlife Fund for Nature.

Some general characteristics of Chilean forests include:

1. A high productivity in some forests (more than 1,000 tons per ha of above ground biomass), and great wood quality of many tree species.
2. An unusual biodiversity and high level of endemism.
3. Conifer species that are among the longest living trees in the world.
4. Dominance of angiosperms over gymnosperms, and of broadleaved over deciduous species.

Chile's floral regions can be divided into four broad regions (but are often split into many more seperate ecological sub-regions, beyond the scope of this introduction).

High Andean plain/steppe

Found in the Andean Mountain Range, extending from Chile's northern boundary at the borders with Peru and Argentina, to the mountains of Region VII. This zone is characterized by its relative aridity and short growing season.

The four representative vegetation associations of the Atacama Puna are Fabiana bryoides - Parastrephia lepidophylla, Festuca chrysophylla - Fabiana bryoides, Pycnophyllum molle - Oxalis exigua and Baccharis incarium - Lampaya medicinalis.

The altiplano of the northernmost portion of the Chilean territory is home to the Browningia candelaris, a candelabrum-shaped cactus. Another cactus species, the Echinopsis atacamensis, grows in the pre-Andean area.

The high Andean region is also characterized by the presence of species of the genus queñoa (Polylepis tarapacana) and llareta (Azorella compacta).

Northern Deserts

Extending from the limit of Region I to Region IV.

The scrub forests of queñoa (Polylepis tarapacana), which probably covered much of the puna until the 16th century, are now only found in damper gullies, having been havested for fuel and construction by early human inhabitants.

An endemic tree of the Norte Grande is the Tamarugo (Prosopis tamarugo), growing mainly in the Pampa del Tamarugal region, some 70km east of the city of Iquique. The bushy tree apparently grows without the benefit of rainfall, and obtains water from dew - allowing the tree to grow on saline soils.

At lower levels different cacti species are found, together with a rich and highly adapted floral diversity which responds to irregular rains, occasionally creating brief 'blooming' deserts. Cacti occur in the coastal desert. Here, there is a great diversity of the genus Copiapoa, recognizable by their distinctive shapes.

San Pedro de Atcama Region

The dryness of the Salar de Atacama allows only the presence grama salada (Distichlis spicata - salt gama), cachiyuyo (Atriplex atacamensis) and other minor herbaceous species. Along the eastern margins where drainage patterns support more species, and away from the hostile saline environment of the Salar, species such as brea (Tessaria/Pluchea absinthioides), petaloxa (Franseria meyeniana), and plants of medicinal use such as rica rica (Acantholippia punensis and Acantholippia trifida) can be found.

Along drainage lines and valleys, the characteristic and well known Cola de Zorro (Cortaderia speciosa or foxtail) are common. Tree species of note in the region of the oasis of San Pedro de Atacama and the pre-cordillera valleys include algarrobo (Prosopis chilensis) and chañar (Geoffroea decorticans).

The altiplano dry steppe areas support a basic flora of pasto (grass) species, of the genera Stipa, Festuca and Deyeuxia, known collectively as paja brava. Also found are matorral scrub species such tolar (Parastrefia and Fabiana species) and té de burro (Phacelia brachyanta). Notable herbaceous species of medicinal use such as chachacoma (Senecio spp), susurco (Mulinum spp), copa (Artemisia spp), pingo-pingo (Acantholippia spp).

South of the Atacama Desert, which largely occupies Chile's 3rd region, cacti become common, first a dwarf species, and then a larger columnar form (Echinopsis chiloensis) predominates. Vegetation becomes dominated by sclerophyllous shrubs adapted to conserve water, with some Nothofagus species at higher altitudes in the coastal ranges.

Central Mediterranean (Matorral) Scrub and Sclerophyllous forest

To some degree the flora of central Chile is of a transition character between the northern and southern zones. It is much more than this, however, for it has a large number of genera and species peculiarly its own, although the region has suffered much destruction of natural habitat through agricultural and industrial development.

In most areas hot dry summers and cool, moist winters produce Mediterranean scrub ('mattoral') with low evergreen trees such as litre (Lithraea caustica), boldo (Peumus boldus), peumo (Cryptocarya alba) and lingue (Persa lingue).

Evergreen species largely predominate here as well as further south. One of the most characteristic trees of this zone is the peumo (Cryptocarya alba), whose dense evergreen foliage is everywhere conspicuous. The quillay (Quillaja saponaria) is another characteristic evergreen tree of this region.

In earlier times the Chilean palm (Jubaea chilensis) was to be found throughout this part of Chile, but it is almost completely extinct due to the destructive extraction process of its sweet sap, from which a syrup is made. Although the original distribution of Jubea chilensis was from 30°40? to 35°20?, this forest type is now restricted to some valleys and piedmonts of the Coastal Cordillera, between 32°20 and 34°30?S. Geographically, this forest type is within the area of the sclerophyllous forest type (see below), and it grows predominantly on western slopes and in humid valleys. Adult specimens can live over 400 years, and the species is the second southern-most palm in the world. Small fragments of Chilean palm can be found within two protected areas - La Campana and Las Palmas de Cocalan.

In the damper southern parts of this region we find 'Maulino' forest (between 100 and 900m), dominated by hualo (Nothofagus glauca), with ruil (Nothofagus alessandrii), pitao (Pitavia punctata) as well as queule (Gomortega keule), the only species in its genus, which is found only in the 8th Region (Biobío).

The sclerophyllous forest type extends across Chile?s entire central region and is characterized by a typical Mediterranean climate, which supports dry open canopy forests and shrub-like trees and includes several forest communities. The common characteristic of these communities is the dominance of sclerophyllous species. This forest subtypes include:

1) Espinal: corresponds to a savanna-like open forest dominated by Acacia caven, with 100 to 300 trees of this species per hectare. It is located in the piedmont of both Cordilleras, from the northern limit of the forest type to 37°S.
2) Mixed Forests: a mixture of sclerophyllous species (P. boldus, Q. saponaria, L. caustica, Cryptocaria alba, Maytenus boaria, Schinus latifolius and Kageneckia oblonga) dominates intermediate elevations in the western slopes of both Cordilleras and the eastern slopes of the Coastal Cordillera, as well as lowlands of the central depression between 37° and 38°S.

Southern Valdivian Temperate Forests

The rich Valdivian temperate rainforests extend across the southern half of Chile. Three native species of the genus Nothofagus; the roble (Nothofagus obliqua), coihue (Nothofagus dombeyi), and raulí (Nothofagus alpina), occur widely and are highly prized for their wood, especially the first, which is misleadingly known as roble, meaning 'oak'.

This eco-region covers the thin continental strip between the western slope of the Andes and the Pacific Ocean, extending between 35?S and 48?S. The snow line is about 2,400m in Central Chile (35?S), descending to 1,000m southwards in the region. The Andes rise to about 3,000m, and at higher elevations the temperate forests are replaced by high Andean vegetation. The precipitation ranges between 1,000mm in the north, to 6,000m per year in the southern most part of the eco-region. The precipitation decreases significantly on the eastern slope of the Andes, with only about 200mm falling annually. These rains are seasonal and are annually concentrated in winter. Biogeographic events, temperature and precipitation gradients, a long history of isolation and recent climatic changes have caused the development of a heterogeneous mosaic of forest types. There are five predominant types of forest systems.

1) Deciduous forest ? transition between Mediterranean type schlerophyllous forests and the wet temperate forests extending southwards. The deciduous forest zone extends from 33°S to 41°S, between Chile?s Regions V and X, and has a mild temperate climate.
2) Valdivian laurel-leaved forest, from 37°45? to 43°30?S lat, dominated by Laureliopsis phillippiana, Aextoxicon puncyatum, Eucryphic cordifolia, Caldelivia paniculata and Weinmannia trichosperma.
3) Northern Patagonian forests, from 43°20? to 47°30? S lat, dominated by perennial species such as Nothofagus dombeyi, Podocarpus rubigena and Drimys winteri.
4) Andean-Patagonian forests. These extend from 37°S to Chile?s southern tip, through the densely forested Southern Andean Mountain Range. The vegetative landscape is distinguishable by the presence of the deciduous southern beech or lenga forests (Nothofagus pumilio), the most common timberline species in the Andean Mountain Range. The presence of snow is an ecological characteristic of these forests. Patagonian Andean forests including Araucaria araucaria and Andean scrub with deciduous Nothofagus species.
5) Evergreen forests with bogs consisting of forests of Nothofagus betuloides and Sphagnum bogs. These occur in mountainous sectors on the western sides of the Patagonian mountains. They are also found on the long narrow band of outer islands that are spread across southern Chile from the island of Chiloé in Region X, all the way to the tip of Chile by Cape Horn (Region XII). Additionally there are forest communities dominated by conifers such as Fitzroya cuppresoides, Pilgemdendron urifernon and Austrocedrus chilensis.

North of Puerto Montt there is little lowland forest remaining, with higher levels dominated largely by deciduous lenga (Nothofagus pumilio) forest. A tree which flourishes in exposed areas is ñirre (Nothofagus antartica). High, dry areas are home to cyprés de la cordillera (Austrocedrus chilensis) and the Chilean pine - also know as the pehuén or araucaria (Araucaria araucana), and known in English as the 'monkey-puzzel tree'.

There used to be huge stands of the araucaria throughout southern Chile, but it is now mostly confined to protected areas in the Lakes Region. It lives for about 3,000 years, can grow to 50m in height and 3m in diameter, it also supports over 70 species of insect. Its seeds are prized by the Mapuche, as well as the choroye parakeet.

Further south is the similarly long-lived alerce (Fitzroya cupressoides), which seeds only when 200 years old and live to an estimated 4,000 years. Again this species has been heavily logged and now surivive mainly in national parks. Species associated with alerce, include the ciprés de las Guaitecas (Pilgerodendron uviferum), the Chilean cypress (Austrocedrus chilensis), lingue (Persea lingue), laurel (Laurelia sempervirens), avellano (Gevuina avellana), luma (Luma apiculata), and many others.

Canelo (Drimys winteri) is another tree of note, sacred to the Mapuche, with elongated green leaves and white flowers at their tips in Sept/Nov.

Chile's national flower is the copihue (Lapageria rosea), a creeper with a deep-pink, elongated bell shaped flower, and grows clinging to trees and larger bushes. Another species of note is the rhubarb related nalca (Gunnera chilena), with its huge umbrella-like leaves.

At lower levels, mostly south of Puerto Montt, we find evergreen forest dominated by the tall coigüe (Nothofagus dombeyi) with tepa (Laurelia philippiana), ulmo (Eucryphia cordifolia) and tineo (Weinmannia trichosperma), with a very dense understory. In the wettest areas thrives a cypress, the cyprés de las Guiatacas (Pilgerodendum uvifera).

The understory is dense and thick, Chusquea bamboos - mainly quila (Chusquea quila) to the north and the more flexible colihue (Chusquea coleou) to the south, together with tree species such as arrayán (Luma apiculata) and other shrubs, including chilco (Fuchsia magellanica) and notro (Embothrium coccineum) which attract hummingbirds with their red flowers.

In spring, flower meadows of wild gentian, daises, vetch, lupins, wood violets and orchids bloom.

Magallanic Forests
The far south Patagonian area is dominated by species-poor sub-Antarctic forests of Nothofagus species, known as Magellanic forest, and covering the western edge of southern South America, extending along the Patagonian Andes and the Chilean Fiords from 47?S to Cape Horn. The northern end of the sub-Antarctic forests is bordered by Valdivian forests, whilst the eastern limit borders with the Patagonian Steppe and grasslands. To the west is the cold Pacific Ocean.

Dominated by coigüe de Magallanes (Nothofagus betuloides, with stunted lenga (Nothofagus pumilio) and ñirre (Nothofagus antartica), and a dense undergrowth composed of a great variety of shrubs and plants, among which are Maytenus magellanica, Gaultheria mucronata, Berberis buxifolia, wild currant (Ribes magellanicum), a trailing blackberry, tree ferns, reed-like grasses and innumerable parasitic plants (including species of the genus Misodendron). Further south the forest is generally open, with a well developed herb layer and over 400 species of moss.