Patagonian grasslands

Last updated
Patagonian grasslands (NT0804)
Camino a Cerro Guido - panoramio.jpg
Natural grasslands next to the road to Cerro Castillo.
Ecoregion NT0804.png
Ecoregion territory (in purple)
Ecology
Realm Neotropical
Biome Temperate grasslands, savannas, and shrublands
Geography
Countries
Coordinates 52°49′59″S69°10′44″W / 52.833°S 69.179°W / -52.833; -69.179

The Patagonian grasslands (NT0804) is an ecoregion in the south of Argentina and Chile. The grasslands are home to diverse fauna, including several rare or endemic species of birds. There are few protected areas. The grasslands are threatened by overgrazing by sheep, which supply high-quality merino wool. Efforts are being made to develop sustainable grazing practices to avoid desertification.

Contents

Location

The Patagonian grasslands extend across eastern Tierra del Fuego in Argentina, and cover part of Santa Cruz Province just north of the Strait of Magellan up to the Gallegos River. They also include the Falkland Islands. [1] [lower-alpha 1] To the north the grasslands adjoin the Patagonian steppe ecoregion. [4] To the west they adjoin the Magellanic subpolar forests ecoregion. [2]

Physical

The ecoregion in South America is divided into a northern mainland section and southern Tierra del Fuego Island section by the Strait of Magellan. The grasslands cover terrain of low mountains, plateaus and plains. The soils are rich, with high levels of organic material. Average annual rainfall is 300 to 400 millimetres (12 to 16 in). [1] Mean temperatures in the far south of Tierra del Fuego are 5.4 °C (41.7 °F), but temperatures may fall below −20 °C (−4 °F). [5]

The ecoregion holds important wetlands including the Tero marsh and lagoons, Rio Pelque marsh, Lago Argentino, Puerto Bandera lagoons, Lake Viedma, Meseta del Tobiana lagoons and Escarchados lagoons. In the coastal region important wetlands include Río Santa Cruz, Monte León, Río Coig, Ría Gallegos, Cabo Vígenes, Bahía San Sebastián, Río Grande, Mitre Peninsula, Beagle Canal and Isla of the Estados. [1]

Ecology

The Patagonian Grasslands are in the Neotropical realm, in the temperate grasslands, savannas, and shrublands biome. [1]

Flora

The northern part of the ecoregion is covered by tundra grasslands. In the center there are high latitude Andean meadows and in the far south there are deciduous thickets. On the Falkland Islands there are swamp forests. [1]

The vegetation is mostly grass-steppe with scattered shrubs. Species include Festuca pallescens , Senecio patagonicus and Plantago maritima . Species found in saline soils near the sea include Atriplex reichei and Lepidophyllum cupressiforme . Common genera include Adesmia, Anarthrophyllum, Berberis, Chuquiraga, Lycium, Mulinum, Schinus and Verbena. The dominant species in the steppe of Tierra del Fuego is the perennial grass Festuca gracillima . Other grasses include Poa atropidiformis , Trisetum species and Hordeum comosum . The most common plant in the valley floors and plains is Hordeum comosum, interspersed with Alopecurus antarticus , Phleum conmutatus , Poa pratensis and Agrosti species. [1]

Fauna

The critically endangered hooded grebe Maca tobiano sobre vinagrilla en lago de la patagonia Argentina.jpg
The critically endangered hooded grebe

The region holds very diverse fauna. Mammals include Patagonian mara (Dolichotis patagonum), southern viscacha (Lagidium viscacia), Wolffsohn's viscacha (Lagidium wolffsohni), Patagonian weasel (Lyncodon patagonicus), Humboldt's hog-nosed skunk (Conepatus humboldtii), cougar (Puma concolor), Falkland Islands wolf (Dusicyon australis) and guanaco (Lama guanicoe). Threatened species include Patagonian mara (Dolichotis patagonum), guanaco, South American gray fox (Lycalopex griseus) and South American fur seal (Arctophoca australis). [1]

Bird include Darwin's rhea (Rhea pennata), Patagonian tinamou (Tinamotis ingoufi), black-chested buzzard-eagle (Geranoaetus melanoleucus), peregrine falcon (Falco peregrinus), band-winged nightjar (Systellura longirostris), Patagonian mockingbird (Mimus patagonicus) and Patagonian yellow finch (Sicalis lebruni). Endemic birds found north of the strait include hooded grebe (Podiceps gallardoi), Magellanic plover (Pluvianellus socialis), chocolate-vented tyrant (Neoxolmis rufiventris), white-bridled finch (Melanodera melanodera), short-billed miner (Geositta antarctica), ruddy-headed goose (Chloephaga rubidiceps) and striated caracara (Phalcoboenus australis). [1] The striated caracara (Phalcoboenus australis) and blackish cinclodes (Cinclodes antarcticus) are found in Tierra del Fuego. Endemic birds in the Falklands are the Falkland steamer duck (Tachyeres brachypterus) and Cobb's wren (Troglodytes cobbi). The Falklands are also important for seabirds such as gentoo penguin (Pygoscelis papua). [1]

Status

Grassland in the Falkland Islands Upland.jpg
Grassland in the Falkland Islands

The World Wildlife Fund gives the ecoregion a status of "Vulnerable". Few people live in the ecoregion. However, grazing livestock and introduced animals have destroyed the natural grassland, particularly tussock grass. [1] Where the sparse vegetation has been damaged the soil is exposed to erosion. [1] Overgrazing by merino sheep is turning the grassland into a desert. [6] In the past Guanacos were the only large grazing animal, and imposed little stress on the semi-arid grasslands. Commercial sheep farming, which began at the end of the 19th century, has had a drastic impact. Palatable grasses have been progressively eliminated, replaced by unpalatable woody plants. [7]

The natural tussock grass is an important resource for endemic birds. Three birds species at risk are the critically endangered hooded grebe (Podiceps gallardoi), the rare ruddy-headed goose (Chloephaga rubidiceps) and the near threatened striated caracara (Phalcoboenus australis), which has suffered from over-hunting. [1]

Conservation

The ecoregion has few protected areas. They include Dicky Private Wildlife Reserve (Refugio Privado de Vida Silvestre Dicky) and Magallanes National Reserve on the mainland, and Reserva Costa Atlántica in Tierra del Fuego. [1] The Patagonian Grasslands of Argentina Conservation Project, organized by The Nature Conservancy, is trying to develop sustainable grazing practices in partnership with scientists and landowners, but it is a challenge to find economic incentives. [6] An Argentine company has worked with The Nature Conservancy to develop protocols and measurements for sustainable grazing, which can be used in branding clothes made of Patagonian wool. The theory, which is controversial, is that if sheep are moved frequently to emulate herds of wild animals avoiding predators they may actually help regenerate the grasslands. The decisions on where and how fast to move them depend on many ecological factors, and some academics are skeptical about whether real benefits can be achieved. [8]

Notes

  1. The World Wildlife Fund (WWF) "WildFinder" application shows the grasslands as part of the Patagonian steppe. [2] This is inconsistent with the WWF's detailed description of the grasslands as a separate ecoregion. [1] However, the term "Patagonian grasslands" may be used to cover all grasslands in Patagonia, including the steppe and the more southern parts. [3] This article takes the narrow definition of the WWF NT0804 ecoregion.
  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Dellafiore.
  2. 1 2 WildFinder – WWF.
  3. Cibils 2005, p. 123.
  4. Dellafiore & (b).
  5. Cibils 2005, p. 125.
  6. 1 2 Nogues 2010.
  7. Cibils 2005, p. 121.
  8. Winninghoff 2013.

Sources

Related Research Articles

<span class="mw-page-title-main">Patagonia</span> Geographical region in South America

Patagonia is a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and glaciers in the west and deserts, tablelands, and steppes to the east. Patagonia is bounded by the Pacific Ocean on the west, the Atlantic Ocean to the east, and many bodies of water that connect them, such as the Strait of Magellan, the Beagle Channel, and the Drake Passage to the south.

<span class="mw-page-title-main">Magellanic subpolar forests</span> Ecoregion of southernmost South America

The Magellanic subpolar forests are a terrestrial ecoregion of southernmost South America, covering parts of southern Chile and Argentina, and are part of the Neotropical realm. It is a temperate broadleaf and mixed forests ecoregion, and contains the world's southernmost forests.

<span class="mw-page-title-main">Guanaco</span> Species of mammal (camelid)

The guanaco is a camelid native to South America, closely related to the llama. Guanacos are one of two wild South American camelids; the other species is the vicuña, which lives at higher elevations.

<span class="mw-page-title-main">Caracara (subfamily)</span> Subfamily of birds

Caracaras are birds of prey in the family Falconidae. They are traditionally placed in subfamily Polyborinae with the forest falcons, but are sometimes considered to constitute their own subfamily, Caracarinae, or classified as members of the true falcon subfamily, Falconinae. Caracaras are principally birds of South and Central America, just reaching the southern United States.

<span class="mw-page-title-main">Striated caracara</span> Species of bird

The striated caracara or Forster's caracara is a Near Threatened bird of prey of the family Falconidae, the falcons and caracaras. It is found in Argentina, Chile, and the Falkland Islands. In the Falklands it is known as the Johnny rook, probably named after the Johnny penguin.

<span class="mw-page-title-main">Puna grassland</span> Type of grassland in the central part of the high Andes

The puna grassland ecoregion, of the montane grasslands and shrublands biome, is found in the central Andes Mountains of South America. It is considered one of the eight Natural Regions in Peru, but extends south, across Chile, Bolivia, and western northwest Argentina. The term puna encompasses diverse ecosystems of the high Central Andes above 3200–3400 m.

<span class="mw-page-title-main">Crested caracara</span> Species of bird

The crested caracara, also known as the Mexican eagle, is a bird of prey in the family Falconidae. It is found throughout Central and South America but has been found in northern Minnesota to Tierra del Fuego. It was formerly placed in the genus Polyborus.

<span class="mw-page-title-main">Patagonian Desert</span> Largest desert in Argentina

The Patagonian Desert, also known as the Patagonian Steppe, is the largest desert in Argentina and is the 8th largest desert in the world by area, occupying 673,000 square kilometers (260,000 mi2). It is located primarily in Argentina and is bounded by the Andes, to its west, and the Atlantic Ocean to its east, in the region of Patagonia, southern Argentina. To the north the desert grades into the Cuyo Region and the Monte. The central parts of the steppe are dominated by shrubby and herbaceous plant species albeit to the west, where precipitation is higher, bushes are replaced by grasses. Topographically the deserts consist of alternating tablelands and massifs dissected by river valleys and canyons. The more western parts of the steppe host lakes of glacial origin and grades into barren mountains or cold temperate forests along valleys.

<span class="mw-page-title-main">Monte Desert</span>

The Monte Desert is a South American desert, lying entirely within Argentina and covering approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza Provinces, plus the western half of La Pampa Province and the extreme north of Río Negro Province. The desert lies southeast of the Atacama Desert in Chile and Peru, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba.

<span class="mw-page-title-main">Chimango caracara</span> Species of bird

The chimango caracara is a species of bird of prey in the family Falconidae, the falcons and caracaras. It is found in Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay, and as a vagrant on the Falkland Islands.

<span class="mw-page-title-main">White-throated caracara</span> Species of bird

The white-throated caracara or Darwin's caracara is a species of bird of prey in the family Falconidae, the falcons and caracaras. It is found in Argentina and Chile.

<span class="mw-page-title-main">Patagonian mockingbird</span> Species of bird

The Patagonian mockingbird is a species of bird in the family Mimidae. It is found in much of Argentina and locally in Chile.

<span class="mw-page-title-main">Patagonian sierra finch</span> Species of bird

The Patagonian Sierra Finch is a species of bird found in the southern regions of South America, particularly in Argentina and Chile. It belongs to the family Thraupidae, which includes tanagers and other seed-eating birds.

<span class="mw-page-title-main">Environment of Argentina</span>

The Environment of Argentina is characterised by high biodiversity.

<span class="mw-page-title-main">Southern Andean steppe</span>

The Southern Andean steppe is a montane grasslands and shrublands ecoregion occurring along the border of Chile and Argentina in the high elevations of the southern Andes mountain range.

<span class="mw-page-title-main">Tierra del Fuego National Park</span> Argentine park

Tierra del Fuego National Park is a national park on the Argentine part of the island of Tierra del Fuego, within Tierra del Fuego Province in the ecoregion of Patagonic Forest and Altos Andes, a part of the subantarctic forest. Established on 15 October 1960 under the Law 15.554 and expanded in 1966, it was the first shoreline national park to be established in Argentina.

<span class="mw-page-title-main">ParanĂ¡ flooded savanna</span>

The Paraná flooded savanna (NT0908) is an ecoregion that borders the southern Paraná River in Argentina. It has largely been converted to agriculture or occupied by urban development, but scattered patches of the original habitat remain along the river.

<span class="mw-page-title-main">Argentine Monte</span> Ecoregion in Argentina

The Argentine Monte (NT0802), or Low Monte, is an ecoregion of dry thorn scrub and grasslands in Argentina. It is one of the driest regions in the country. Human settlements are mainly near water supplies such as rivers or oases. Deforestation and over-grazing around these settlements have caused desertification.

<span class="mw-page-title-main">Patagonia National Park (Chile)</span>

Patagonia National Park is a national park in the Aysén Region of Chile. Once a private nature reserve operated as a public-access park, it was donated to the government of Chile by Tompkins Conservation in 2018.