Encyclopedia on Biomes and Ecosystems
For Biomes and Ecosystems: An Encyclopedia we present baseline information on two highly endangered ecoregions of Chile. These ecoregions are characterized by extraordinary levels of endemism because Chile is a biogeographical island, bordering the sea to the West and isolated from the rest of South America by the Andes mountains to the East. Read More
- Funk, S.M., 2013. Chilean Matorral Forests, in: Howarth, R.W. (Ed.), Biomes and Ecosystems: An Encyclopedia. Salem Press, pp. 460–461.
Category: Forest Biomes.
Geographic Location: South America.
Summary: The Chilean Matorral ecosystem is rich with wildlife, much of it endemic, but human activity and low protection status present a continuing challenge.Read More
The Matorral is a narrow stretch of land in central Chile, extending south from one of the driest deserts in the world, the Atacama, to the mixed deciduous-evergreen temperate zone known as the Valdivian forests. The Matorral is about 350 miles (563 kilometers) long and 62 miles (100 kilometers) wide. Here, the summers are hot and dry and prone to drought conditions; winters are wet and mild. The mean annual temperature is 54 degrees F (12.2 degrees C). The native plant and animal communities in the Chilean Matorral biome are species-rich with a very high proportion of endemism (found only in this ecosystem), particularly among plants.
Flora and Fauna
As a plant community, Matorral refers to a zone of sclerophyll shrubs and trees (i.e., evergreen “hard-leaved” woody vegetation with small, waxy leaves that prevent water loss in the dry summer); cacti, bromeliads, and palms; and diverse understories of herbs, vines, and grasses. Most of the present scrubland was created by human activity and is a successional remnant of the native sclerophyllous forest. It now exists as a mosaic of shrubs and trees within a matrix of naturalized herbaceous plants.
This land hosts animals that are specially adapted to their unique habitat and cannot be found anywhere else on Earth—making them extremely rare and dependent upon protected areas for their survival. These include many small mammals such as the chilla, a fox-like animal; the yaca (mouse opossum); and the kodkod, the smallest wildcat in the Americas. Several lizard species are also endemic to the Chilean Matorral, as are 15 known species of birds. Among the latter are the Chilean mockingbird; three varieties of tapaculo; two species of parrots; the giant hummingbird; and some carnivorous species such as the aplomado falcon, cinereous harrier, and the short-eared owl.
The ecoregion’s core, the Central Valley, constitutes Chile’s most intensively inhabited area. It is very fertile and is the agricultural heartland with booming wine, vegetable, and fruit industries. In the more southerly parts fruit, crops, pasture, and fire-prone pine and eucalyptus plantations are widespread. Because of the high agricultural value, the Central Valley of Chile has been highly modified since the arrival of Europeans. Although
early settlers introduced fires around 14,000 years ago, it is only since Spanish colonization that fires have become frequent. The Matorral is poorly fire-adapted; human-induced fires cause major and long-lasting damage. Seeds of native sclerophyllous species do not survive even low-intensity fires. Moreover, the capacity of regeneration of these sclerophyllous species is very low—even after cessation of livestock grazing—because of the constant soil disruption and shoot consumption pressures from introduced rabbits and hares.
Logging and mining, with the ensuing roadways and pollution that are created, have contributed to habitat loss here. The increasing density of the road network goes hand-in-hand with invasions by exotic species and with deforestation, both being positively correlated with distance to primary roads. The current rate of introductions of invasive plant species is unprecedented in regional history. Intentionally and unintentionally, nonnative species have spread fast and uncontrolled, further promoted by the secondary plant and animal invaders that come with the introduction of controlled populations of livestock. The consequences can be severe. Introductions not only modify patterns of abundance and distribution of native species, they also cause local extinctions and, especially in the case of plantations of exotic trees, can significantly modify soil, microclimate and fire characteristics, thus irreversibly altering the environmental physiology of the ecosystem.
Despite its highly unique biodiversity, the Chilean Matorral is perhaps the least protected of the world’s five major Mediterranean regions. Moreover, it is the least protected region in Chile at large. The World Wildlife Fund has assessed this ecoregion’s conservation status to be Critical/Endangered. There remains a significant proportion of currently unprotected natural and semi-natural land with conservation potential, while human pressure increases continually.
More intensive and efficient protection and conservation action is urgently required; some conservation schemes on private land and neighborhood initiatives have recently emerged. In 2010, the new Altos de Cantillana Nature Sanctuary, located approximately 25 miles (40 kilometers) from Santiago, was established by the Chilean government, protecting 6,778 acres (2,743 hectares) of Matorral. Although there is relatively little protected public land in Chile, the concept of private land trusts has recently gained momentum. These small parcels are considered complementary to the National Public System of Protected Areas—Sistema Nacional de Áreas Silvestres Protegidas (SNASPE), which unifies conservation efforts within and between the country’s national parks, reserves, and monuments.
Global warming scenarios generally point to warmer and drier climate in Mediterranean biomes such as the Chilean Matorral forests. The pressure this will exert on plant and animal species to relocate will only be exacerbated by increased likelihood of fire; together these vectors point to accelerated habitat fragmentation.
- Funk, S.M., 2013. Valdivian Temperate Forests, in: Howarth, R.W. (Ed.), Biomes and Ecosystems: An Encyclopedia. Salem Press, Ipswich, MA, USA, pp. 1263–1265.
Category: Forest Biomes.
Geographic Location: South America.
Summary: A virtual continental island between the Pacific Ocean and the Andes Mountains, these forests boast high species endemism but face growing threats from human activities and climate change.Read More
Phylogenetic uniqueness, too, is high; for example, there are 32 genera of trees of which four-fifths are monotypic, meaning the genus comprises just a single species. These factors all indicate long and ancient isolation.
Geography and Climate
The wet temperate forests dominate the narrow strip between the western slopes of the Andes and the Pacific Ocean from just north of the Chilean capital Santiago, to the southern tip of the Taitao Peninsula. The forests are found in two north-south running mountain ranges as well as the intermediate valley. The peaks of the Andes are higher toward the north, up about 23,000 feet (7,000 meters), than the southern range, which peaks at 13,123 (4,000 meters). Treelines are the same, at roughly 7,874 feet (2,400 meters). Forests are replaced by montane grasslands and shrublands above the treeline in the north, but by temperate grasslands, shrublands, and savannas further south.
The Andes were extensively glaciated during the Pleistocene, although volcanic rock and deposits have since covered most of the glaciated surfaces. The coastal range, Cordillera de la Costa, is a mountain belt rising to 4,265 feet (1,300 meters), parallel to the coast and the Andes, which remained largely unglaciated. It submerges off the shore south of 42 degrees south, but forms the large Chiloé Island and the Chonos Archipelago. Between the two mountain ranges lies a low structural depression valley, which submerges into the ocean at the same point.
The depression is filled with volcanic ash, erosion and glacial deposits; this fertile valley in the northern reaches of the biome constitutes Chile’s agricultural heartland. Its climate results in a mediterranean vegetation type separating the temperate forests of the eastern and western mountain ranges. These two temperate systems join further south.
The northward flowing Pacific Ocean currents, together with the dominant moist, westerly onshore winds, produce a maritime cool climate overall, with higher humidity and precipitation in the coastal range than in the Andes, and on the western slopes than on eastern slopes. In the south, rain falls year-round, with annual precipitation exceeding 236 inches (6,000 millimeters). A shift toward a winter-rainfall regime and annual precipitation of about 39 inches (1,000 millimeters) occurs in the north. Coastal upwelling causes year-round coastal fog. Average annual temperatures vary between maxima of 55–70 degrees F (13 to 21 degrees C) and minima of 39–45 degrees F (4 to 7 degrees C) in the north and south, respectively.
Southern beeches of the genus Nothofagus are widespread; this genus is found around the southern Pacific Rim, indicating a common evolutionary history reaching back to Gondwana.
Precipitation and, to a lesser extent, disturbances and latitudinal and altitudinal temperature differences determine the distribution of vegetation types. The shade-intolerant Nothofagus species, which do not regenerate in undisturbed old-growth forests, are characteristic. They are widespread in the Andes due to periodic disturbances including volcanic eruptions and avalanches. Disturbances are less important in the coastal mountains where shade-tolerant trees are abundant.
Five main types of forest ecosystems can be distinguished: Northern deciduous forests with dominant Nothofagus species including rauli and roble mark the transition to mediterranean forests. Valdivian laurel-leaved forests are typical for the Nothofagus gap, and are dominated by broadleaf evergreen tree species including tepa, ulmo, tiaca, and tineo trees, and an understory of myrtle trees and arrayán.
Northern Patagonian forests are dominated by evergreen species including coihue (N. dombeyi). Patagonian Andean forests include the monkey-puzzle tree, a living fossil and Chile’s national tree, and the valuable and threatened alerce; high Andean scrublands with Nothofagus dominate nearer the treeline. Magellan’s beech (N. betuloides) and bogs of Sphagnum mosses typify southern evergreen forests.
Endemic bamboo species are characteristic understory species and can forms dense, pure thickets. Edible large-leaved perennial nalca and ferns are widespread. The copihue, Chile’s national flower, is a representative pioneer in disturbed areas.
Mammal endemism is relatively low here—but there are five endemic genera including the monito del monte, an arboreal marsupial. Endemism levels for both reptiles and amphibians are high, with many species restricted to very small areas. They constitute important species targeted by the Alliance of Zero Extinction scheme.
About 30 percent of the bird species here are estimated to be endemic. There is just a single species of hummingbird, (Sephanoides sephaniodes), but it is vital to the one-fifth of woody
plant genera that depend on its visits to spread pollen between their typically red, tube-like flowers.
Threats and Conservation
Before the arrival of the Spanish colonizers centuries ago, the indigenous Mapuche people cultivated only a few open areas; the forest cover remained intact. After the arrival, heavy logging, burning, land clearance and habitat degradation set in. Invasive species and, since the 1970s, the ever-increasing pine and eucalyptus plantation forests have caused significant damage. Today, few primary forests, especially in the coastal range, remain.
Chile’s economy is one of the fastest-growing in Latin America, exercising strong human pressures on remaining forest fragments through tourism, construction of highways, and forest clearing for power lines connecting the economic heartland with the hydroelectricity-producing areas in the south. There is a large network of protected areas, but—especially in the north—they concentrated at middle elevations in the Andes, leaving the coastal range under further pressure. The area with the highest biodiversity (36–41 degrees south) has the lowest percentage of protected areas.
The analysis of historic plant distributions shows substantial variations, and indicates a high sensitivity of temperature regimes. Climatic change and geographic isolation seem to have resulted in a net loss of species over time, which lends credence to current observations that this ecoregion is highly susceptible to global warming.
The Valdivian Temperate Forests ecoregion is part of a Conservation International hotspot. It constitutes—together with the Juan Fernández Islands—a World Wildlife Fund Global 200 ecoregion, and also belongs to the Top 100 Ecoregions, a list of those biomes with the highest richness-adjusted endemism of vertebrates in the world.
However, intensive logging and land conversion for forest plantations, agriculture, and economic development severely threaten this biome—in particular by fragmenting habitats and opening the door to invasions by exotic plants and vertebrates.