Sangay National Park lies in the Andean Cordillera Oriental in central Ecuador, sharing its territory amongst Morona-Santiago, Tungurahua, Chimborazo and Cañar provinces. The official boundary is 1° 27'-2° 15'S, 78° 04'-78° 31'W, enclosing a 517,765 ha area, of which the northern 271,925 ha are Natural World Heritage Site.
The 271,925 ha area was gazetted as a wildlife reserve in 1975, this status being changed to National Park in 1979. In 1983 it was declared Natural World Heritage Side by UNESCO, to be eventually listed as a NWHS in Danger in 1992 due to the impacts of the construction of the Guamote-Macas road. In that same year 1992, Ecuatorian Ministry, presumably without being required to, almost doubled Sangay Park's area, but this extended portion is not part of the NWHS.
The topography of Sangay Park is dominated by three huge volcanoes, from N to S, Tungurahua (5,016 m), Altar (5,320 m) and Sangay (5,230 m). These three strato-volcanoes originated from Tertiary and Quaternary volcanism, about 3-4 million years ago (check). Tungurahua and Sangay are both presently very active. Tungurahua is violently erupting since August 1999. Sangay daily ejects hot rocks and tephra. The dormant volcano Altar has a collapsed caldera to the west, crowned by vast glaciers. Presumably the collapse of the hanging glaciers onto the Laguna Amarilla within the caldera was the cause of the huge alud of rock and mud along the Rio Blanco bed in October 2000, which destroyed Collanes Pampa and dammed Rio Chambo.
To the E, between 800 m and 1300 m, the Park consists of alluvial fans, whose oldest segments have been cut by deep up-to-200-meters canyons. Adjacent to the alluvial fans, both to the NE and SE, the Eastern foothills raise, a broken relatively low mountain chain between 1,000 and 2,000 meters. The NE foothills are known as Flute Mountain Range. This low zone mainly consists of Mesozoic and Tertiary volcanic and sedimentary rocks.
The High Andes zone represents the intermediate and upper parts of the Cordillera Oriental, with elevations ranging from 2,000 to more-than 5,000 meters. It is an area of extremely rugged topography with deep, steepy valleys, abundant cliffs and many rocky jagged peaks. Most of this zone is underlain by pre-Cretaceous metamorphic and plutonic rocks.
Three subzones can be distinguished here: 1) subglacial subzone from 2,000m to 3,000m, comprising intermediate levels that have not experienced past glacial activity; 2) glaciated subzone (3,000-4,500 m), characterized by glacial features such as arêtes, cirques, and U-shaped valleys with meandering rivers; 3) volcanic subzone is dominated by the presence of lava and volcanic ash deposited during the Pleistocene and later. It includes the upper cones and surrounding flanks of the three main volcanoes.
The major rivers, draining eastwards into the Amazon Basin, are the Llushin, Palora, Puela, Volcan, Upano, Namaquimi and Sangay Rivers (check maps), all characterized by dramatic variations in level. Run-off is extremely rapid, due to high rainfall and steep slopes, and erosion is substantial, although controlled by thick cloud forests. Numerous waterfalls occur, especially in the hanging valleys of the glaciated zone and along the eastern edge of the Cordillera. Several lakes are present, like the 5 km long Laguna Pintada, the Shararumi Lagoons cluster, the Atillo-Osogoche Lagoons.
Above 4,500 meters, in limited areas around the main volcanoes, rocky lithosols can be found. The ash from Sangay has recently formed young soils and is found both in vicinity, and, more extensively, to the east of the cone. A thin layer of organic soil covers the ashy base. Black Andean soils occur extensively in the eastern Paramos, between 3,000 and 4,500 meters, and comprises volcanic material. Black Andean soils are also found in the cloud forests on the upper exterior slopes of the Cordillera Oriental, along a variably N-S oriented band, particularly in areas of high rainfall. Moist reddish hydrolytic latosols cover much of the eastern region where subtropical forest expand. These are generally acid and heavily leached.
Although the park is situated in the tropics, just south of the Equator, the elevation range is such that it has a subtropical, temperate and alpine climate. Rainfall is strongly influenced by orographic effects. The eastern side of the Cordillera receives the greatest rainfall as air masses from the Amazon Basin move up over the Andes. The mean annual rainfall at Pastaza, in the immediate north-east of the park is 4827mm, whilst Macas in the south-east annually receives 2414mm. Conversely, a mean annual rainfall of only 633mm has been recorded at Penipe beyond the western boundary. Seasonal variation is more marked in the west, with only 122 days of rain recorded in Riobamba. The wettest period varies from site to site, but generally is from April to October. Temperatures remain relatively constant throughout the year, although there is considerable diurnal variation. The mean annual temperature on the east is 20° C, with a mean maximum and minimum of 25.4° C and 16.4° C, respectively. Absolute maximum and minimum temperatures recorded are 31° C and 10° C, respectively. Progressively lower temperatures are recorded at increasing altitudes and at the highest elevations, temperatures never rise above 0° C. A permanent snow line occurs at about 4,800m above sea level.
Biodiversity is assumed to reach staggering levels, though fauna and flora has never been comprehensively studied. Species distributions correspond to altitudinal zones. Preliminary species lists date back to Macey et al. (1976).
Mammals At the highest altitudes Tapirus pinchaque (mountain tapir), Felis concolor (puma), Caria sp. (guinea pig) and Dusicyon culpaeus (Andean fox) occur. Elsewhere Tremarctos ornatus (spectacle bear), Panthera onca (jaguar), Felis pardalis (ocelot), Felis wiedii (margay), Odocoileus virginianus (white-tailed) , Mazama rufina (brocket deer), Pudu mephistophiles (pudu) and Pteronura brasiliensis (giant otter) are found. Opossum Family (Marsupials) is also present.
Birds Some 400-500 species of birds may be present, although comprehensive inventories have never been compiled. Sangay Park contains two Endemic Bird Areas, the Central Andean Páramo, home to ten bird species of restricted range, and the Eastern Andes of Ecuador and Northern Peru, home to 15 restricted-range species. Emblematic species include Vultur gryphus (condor), seen particularly around the mountain area of Altar and Cubillin-Quilimas massif (the latter are not part of Sangay Park), Rupicola peruviana ecuatorialis (cock-of-the-rock), which exists in substantial populations in inaccessible upper forest areas of the eastern Andean slopes, Patagona gigas (giant hummingbird), Marganetta armata (torrent duck), Sarcoramphus papa (king vulture) and Elanoides forficatus (swallow-tailed kite). A preliminary species list is given in Macey et al. (1976).
Despite the fact that Sangay Park harbours notable populations of condors, the area is not part of the Condor Bioreserve, which extends over Cayambe-Coca Ecological Reserve, Antisana Ecological Reserve, Cotopaxi National Park, and Sumaco-Napo-Galeras National Park.
Vegetation A high diversity of vegetation types is present, depending on altitude and rainfall, ranging from paramo alpine zones to the subtropical rain forests of the Amazon Basin - the vegetation growing more luxuriant on the wetter eastern slopes. At least 3,000 species are known to be present in the Park. Some 93 families, 292 genera and 1,566 species have been identified in the Andean forests of Ecuador above 2,400m, and most of these genera are represented in Sangay (WWF and IUCN, 1997)
Alpine rain tundra has formed at the highest levels just below the snow line, being dominated by lichens and bryophytes. A subalpine rain Paramo zone occurs below this. It is characterised by three main vegetation types: Festuca tussock grassland; areas dominated by cushion plants and other low-growing species; and undisturbed areas dominated by bamboo Nuerolepsis sp.. The bottom altitudinal limit of this zone has been artificially lowerered in the west by anthropogenic burning. Montane wet forest is found in valleys to the west with pure stands of Polylepsis sp. or Gnoxys sp. associated with Buddleia incana where undisturbed. At lower elevations, there is a greater variety of small trees and shrubs, including Senecio vaccinoides, Diphostephium sp., Vaccinium spp., Miconia salicifolia, Brachyotum spp., Myrtus communis, Osteomeles spp. and Monnina crassifolia. Montane rain forest has developed on the wetter eastern slopes, and occurs below 3,750 meters. The vegetation of the upper half of this zone attains approximately five metres and is dominated by Nuerolepsis sp. and Myrtus communis associated with Monnina crassifolia, Baccharis teindalensis, Disphostephium lavandulaefolium and Gnoxys spp. Below 3,000 meters, the vegetation develops into forest up to 12 meters high, dominated by Weinmania sp. and Oreopanax sp.. Between 2,000m and 3,000m lower montane rain forest occurs on steep-sided valleys. The canopy attains 40 meters and includes Podocarpus oleofolius, Oreopanax sp., Weinmania sryadifolia (not at MBG W3T). An understory layer is formed by small trees such as Miconia sp. and a third layer by Piper ecuadorensis (not at MBG W3T), Cyathea sp. and Bocconia sp.. Ferns, epiphytes and orchids are abundant. Pure stands of Alnus jorullensis are found in disturbed areas, and towards 2,000m, Cecropia sp., Cedrela odorata (cedro), palms and Rubiaceae are present. Subtropical rain forest occurs below 2,000m where temperatures range from 18° C to 24° C and rainfall may reach 5000mm annually. Species diversity is very high and members of the Lauraceae and Moraceae family such as Ficus spp. and Chlorophora spp., palms, Cedrela odorata and wild avocado Persea sp. are present. Undergrowth species such as Selaginalla sericea (not at MBG W3T) and brightly coloured flowers of the Gesneraceae and Lobeliaceae families are common. This formation receives less rainfall in the south, forming a subtropical wet forest, although there is no clear distinction with wetter areas. Centropogon trachyanthus is endemic to this area (Macey et al. 1976).
Based on data kindly made available by the World Conservation Monitoring Center, Cambridge, UK - Reproduced with permission.