| Puna grassland | |
|---|---|
 Puna grassland in the Chilean altiplano | |
 | |
| Geography | |
| Area | 586,100 km2 (226,300 sq mi) |
| Countries | |
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, [1] 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.
The puna is found above the treeline at 3200–3500 m elevation, and below the permanent snow line above 4500–5000 m elevation. It extends from central Peru in the north, across the Altiplano plateau of Peru, Chile and Bolivia, and south along the spine of the Andes into northwest Argentina.
Other sources claim that it goes on Suni (high plateaus and cliffs, some agriculture) and from 4000 m to the snow line (permafrost and alpine desert) of puna grassland (mountain tops and slopes, much colder). [1]
The puna is a diverse ecosystem that comprises varied ecoregions labeled wet/moist puna, dry puna and desert puna.
This ecoregion is a high elevation, wet, montane grassland in the southern high Andes, occurring from northern Peru to northern Bolivia. The wet puna shares its border on the west with the Sechura desert and the east with the wet Peruvian Yungas. The characteristically mountainous landscape contains high lakes, mountain valleys, snow-covered mountains, and plateaux. [2] The high elevation of the wet puna (4200 to 5000 m) causes the area to have large temperature differences between night and day. The average annual temperature is low, ranging from 5 to 7 °C; with night frost periods from March to October. Temperatures shift from characteristic summer highs in the day and drop to winter lows at night. This extreme temperature shift has caused selective adaptation to occur and many endemic plants such as the Culcitium, Perezia, and Polylepis center their diversity in the wet puna. [3] The ecoregion contains snow-capped peaks, glacial lakes, and several rivers that originate in the Cordilleras. The biggest lake in the ecoregion is Lake Titicaca, which is the highest navigable lake in the world, at an elevation of 3800 m (above sea level). The Suches and Tiwanacu rivers in Bolivia are the lakes tributaries. The areas in the north surrounding Lake Titicaca have eight wet months, and the areas in the south have one to two wet months. [2] The average precipitation in this region ranges from 400 to 2000 mm.
This ecoregion is a very dry, high elevation montane grassland of the southern high Andes. It extends into northern Chile and northwest Argentina and east into western Bolivia occurring above 3500 m between the tree and permanent snow lines. The vegetation of the dry puna consists of tropical alpine herbs with dwarf shrubs. Within the dry puna are salt flats, high plateaus, snow-covered peaks and volcanoes. [4] Dry puna is distinguished from the other types of puna by its diminished annual rainfall. The dry puna has an 8-month long dry season and receives less than 400 mm of rainfall each year. [3] The region lies at an elevation of 3500–5000 m above sea level. The dry puna is oligothermic as well. The average temperatures in this ecoregion range from 8 to 11 degrees Celsius and are lowest in the south. As a result of the elevation, varied temperatures and lack of rainfall, the Central Andean dry puna is a unique ecoregion with highly adapted flora and fauna. The southern region of the dry puna encompasses an even drier puna known as the desert puna. In the desert puna the average rainfall ranges from only 51–406 mm. The desert puna is dominated by the huge salt lakes and is known for the scattered halophytes around and in the depressions. [3] These salt lakes are home to the endemic Andean flamingo.
The World Wildlife fund defines three distinct puna sub-ecoregions:
Puna soils are composed of an organic rich layer and a stony layer. The average soil profile is 33 cm deep. [6] The puna ecosystem has a low diversity of bacteria in its soils. [7] The rhizosphere of the grasses are dominated by the Bacillas species, these organisms are composed of dormant cells that enable them to survive in the extreme climatic conditions in the puna ecosystem. The dormant bacterial community of puna grasses is similar to those found in desert soils. [7]
The puna flora is characterized by its unique assemblages of cushion and mat forming species. Many of these species, most notably the large Azorella compacta (Yareta) has been heavily harvested for fuel and medicinal use. [8] The vegetation with the puna grassland displays complex patterns of spatial variation, despite the low cover and overall density. [8] The puna belt which ranges from wet puna in the north of the Andes to dry puna to the southwestern Andes is composed mostly by poaceae (Grasses) and shrubs of the asteraceae (daisy) family. [9] Other representative grasses include species Jarava ichu ("Paja Brava"), Calamagrostis vicunarum ("Crespillo"), and Festuca dolichophylla ("Chillihua"). [6]
There are several main rock unit formations in the Puna with distinct soil conditions that can be used to identify the main flora of each area. Up to 3000 m above the desert, the arid vegetation of the mountainous steppe is characterized by columnar cacti, arid shrubs and herbs. Vegetation located between 3800 and 4000 m are sustained by brown andic soils on ash-fall deposits and includes many endemic plant species as Hersodoma arequipensis , Piplostephium tacorense and Opuntia corotilla . In the wettest area shrubby vegetation of families asteraceae, fabaceae and solanaceae dominate. [9] The puna is generally drier than the páramo montane grasslands of the northern Andes.
Native mammals include (domesticated) llama and alpaca, and their wild relatives, the vicuña and guanaco. The rare Taruca deer is shy and reserved. Also present are well-known rodent species, such as chinchilla, paca, and the montane guinea pig. Among carnivorous animals, there are puma (mountain lion), Pampas cat, the rare Andean mountain cat, Andean fox, and some Spectacled bear. Relatively few birds, such as the Darwin's rhea, Andean condor, and certain miners and yellow-finches, are found in the vast expanses of puna grasslands; however, many more birds are associated with the highland lakes and marshes that are found in the puna. The most common examples are the Andean goose, Andean flamingo, Andean avocet, giant coot, puna teal and diademed sandpiper-plover. The highland puna is a biome that encompasses relatively large reserves.
Bird populations in the puna ecosystem are surprisingly diverse for such a harsh and extreme environment. For example, the Lauca National Park includes 148 species of birds, which represents about one third of the entire Chilean bird population. Many of these species are rare and attract visitors to the area. One example of this rare avifauna is the giant flightless Darwin's rhea (Rhea pennata), which is similar to the ostrich found in the Old World, reaching up to one meter in height and 20 kg in weight. [10] The puna also includes a great variety of aquatic species particularly at Chungará Lake located in northern Chile. The puna ecosystem has a great diversity of freshwater fish. Some of these include the giant coot, the silvery grebe, the Chilean teal, and the diademed sandpiper-plover (one of the rarest shorebirds in the world). [10]
Puna grasslands are being rapidly depleted by human activity, and as a result need much attention in the conservation realm. Numerous factors can lead to the cause of this destruction, but the preservation of it depends almost entirely on to what degree humans are populating the area. Humans dramatically shape the ecosystem through the conversion of much of the land to farming grounds and grazing areas. [3] Due to the high demand for cooking and heating fuel among the residents of the area, much of the land is degraded. For example, trees of the polylepis genus used to be easily found throughout the ecosystem and now are scarce. [11]
People of this region cultivate barley, potatoes and maca. Alpacas, vicuñas, and guanacos are raised for wool, and llamas for wool and transport. Human habitation in the puna is widespread and tends to increase to the east, toward the moister areas. Native tubers and grains are cultivated over large areas of the central puna. The inhabitants of this region cultivate native tubers (potatoes and maca) along with non-native grains such as barley and native pseudocereals such as quinoa. Alpacas, vicuñas, llamas, and guanacos are raised for wool and, as a result, most of the entirety of the puna is under the effect of animal grazing. Cattle, horses, and donkeys are localized in the wet/humid puna while llama, sheep and alpaca can be raised in both the wet and drier areas of the puna. [3]
The most widespread influence on the grasslands is extensive grazing combined with the effects of fire. Grazing dries out the land, making it more susceptible to fire. Once a land has been exposed to fire, it makes it more likely to burn again, creating a feedback loop that leads to damage of the ecosystem. Fire often accompanies grazing as a management tool and is one of the main threats to the grasslands. The drier areas are being threatened with progression to desertification. [3] Despite the fact that the puna grasslands experience heavy grazing, as an ecosystem it is highly resilient. In these areas of high grazing, successional species of grass and forbs grow back thick, thereby preserving the soil which means its potential to rebound is higher. [11]
The grasslands are also influenced more locally by agriculture, mining, and waste disposal depending on the concentration of the population. There are two predominant forms of management of the puna grazing lands. The first is communal. In this form of management, the community controls the land and every member of that community grazes livestock. This generally leads to overgrazing and degradation of the land. The second style of management is cooperative. This type of management originated from a movement that took land from large landholders and turned it over to council composed of workers. Agronomists and animal scientists see over the land and make sure the grazing is sustainable. [11]
Though there are a significant number of problems in puna grasslands, mostly being attributed to overgrazing, there are measures being taken to improve the current situation. These impact measures are minimal however, since the ratio of protected areas to the rest of the ecosystem is minute. A growing population, construction of new roads, and mining activities are all acting as hindrances to the conservation of the ecosystem. [3] Luckily, awareness is being raised about the problem, and steps are being taken to help improve its preservation. Currently range management programs are being introduced in many of the neighboring universities to research new ideas that implement little technology and can help restore the ecosystem. With the right management, the puna grasslands can rebound and support the growing populations of the surrounding areas. [11] Ultimately however, it is up to the local individuals of the area to coordinate other ways they can receive income in ways that does not harm the land. [3]
Andean Continental Divide
| Westside | Eastside |
|---|---|
| Chala , dry coast | Lowland tropical rainforest or Selva baja |
| Maritime Yungas | Highland tropical rainforest or Selva alta |
| Maritime Yungas | Subtropical cloud forest or Fluvial Yungas |
| Quechua - Montane valleys | Quechua - Montane valleys |
| Tree line | Tree line - about 3,500 m |
| Suni, scrubs and agriculture | Suni, scrubs and agriculture |
The Global 200 is the list of ecoregions identified by the World Wide Fund for Nature (WWF), the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". For example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.
The Great Basin Desert is part of the Great Basin between the Sierra Nevada and the Wasatch Range. The desert is a geographical region that largely overlaps the Great Basin shrub steppe defined by the World Wildlife Fund, and the Central Basin and Range ecoregion defined by the U.S. Environmental Protection Agency and United States Geological Survey. It is a temperate desert with hot, dry summers and snowy winters. The desert spans large portions of Nevada and Utah, and extends into eastern California. The desert is one of the four biologically defined deserts in North America, in addition to the Mojave, Sonoran, and Chihuahuan Deserts.
The Altiplano, Collao or Andean Plateau, in west-central South America, is the most extensive high plateau on Earth outside Tibet. The plateau is located at the latitude of the widest part of the north–south-trending Andes. The bulk of the Altiplano lies in Bolivia, but its northern parts lie in Peru, and its southwestern fringes lie in Chile.
Páramo may refer to a variety of alpine tundra ecosystems located in the Andes Mountain Range, South America. Some ecologists describe the páramo broadly as "all high, tropical, montane vegetation above the continuous timberline". A narrower term classifies the páramo according to its regional placement in the northern Andes of South America and adjacent southern Central America. The páramo is the ecosystem of the regions above the continuous forest line, yet below the permanent snowline. It is a "Neotropical high mountain biome with a vegetation composed mainly of giant rosette plants, shrubs and grasses". According to scientists, páramos may be "evolutionary hot spots", that meaning that it's among the fastest evolving regions on Earth.
The Yungas is a bioregion of a narrow band of forest along the eastern slope of the Andes Mountains from Peru and Bolivia, and extends into Northwest Argentina at the slope of the Andes pre-cordillera. It is a transitional zone between the Andean highlands and the eastern forests. Like the surrounding areas, the Yungas belong to the Neotropical realm; the climate is rainy, humid, and warm.
When the Spanish arrived, they divided Peru into three main regions: the coastal region, that is bounded by the Pacific Ocean; the highlands, that is located on the Andean Heights, and the jungle, that is located on the Amazonian Jungle. But Javier Pulgar Vidal, a geographer who studied the biogeographic reality of the Peruvian territory for a long time, proposed the creation of eight Natural Regions. In 1941, he presented his thesis "Las Ocho Regiones Naturales del Perú" at the III General Assembly of the Pan-American Institute of Geography and History.
Lauca National Park is located in Chile's far north, in the Andean range. It encompasses an area of 1,379 km2 of altiplano and mountains, the latter consisting mainly of enormous volcanoes. Las Vicuñas National Reserve is its neighbour to the south. Both protected areas, along with Salar de Surire Natural Monument, form Lauca Biosphere Reserve. The park borders Sajama National Park in Bolivia.
The Tropical Andes is northern of the three climate-delineated parts of the Andes, the others being the Dry Andes and the Wet Andes. The Tropical Andes' area spans 1,542,644 km2 (595,618 sq mi).
The term Interandean valles refers to those valleys located in the Andes mountains.
The Central Andean dry puna (NT1001) is an ecoregion in the montane grasslands and shrublands biome, located in the Andean Altiplano in South America. It is a part of the Puna grassland.
The Eduardo Avaroa Andean Fauna National Reserve is located in Sur Lípez Province. Situated in the far southwestern region of Bolivia, it is the country's most visited protected area. It is considered the most important protected area in terms of tourist influx in the Potosí Department.
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.
The Southern Andean Yungas is a tropical and subtropical moist broadleaf forest ecoregion in the Yungas of southwestern Bolivia and northwestern Argentina.
The Central Andean puna is a montane grasslands and shrublands ecoregion in the Andes of southern Peru, Bolivia, and northern Argentina.
The Central Andean wet puna is a montane grasslands and shrublands ecoregion in the Andes of Peru and Bolivia.
The Northern Andean páramo (NT1006) is an ecoregion containing páramo vegetation above the treeline in the Andes of Colombia and Ecuador. In the past, when the climate was cooler, the treeline and the páramo units were lower and the units were connected. During the present warmer Holocene epoch the páramos have migrated uphill, shrinking and becoming isolated. They contain many rare or endangered species, some of them restricted to a narrow area of one mountain or mountain range. The ecoregion is relatively well preserved, but faces threats from over-grazing and farming.
The Cordillera Central páramo (NT1004) is an ecoregion containing páramo vegetation above the treeline in the Andes mountain range of northern Peru and southern Ecuador. Due to its isolation there are high levels of endemism. Despite many human settlements and some destruction of habitat by agriculture and mining, the ecoregion is relatively intact.
The Bolivian montane dry forests (NT0206) is an ecoregion in Bolivia on the eastern side of the Andes. It is a transitional habitat between the puna grasslands higher up to the west and the Chaco scrub to the east. The habitat is under severe stress from a growing human population.
Distichia muscoides is a species of plant in the rush family Juncaceae. It is native to the Andes of South America where it grows in upland wetland areas known as bofedales.
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