SANGAY NATIONAL PARK
This Park in the central Andes is the largest area of unaltered wild land in the country’s eastern Cordilleras. It has outstanding natural beauty, two snow-capped active volcanoes and a range of ecosystems from the tropical rainforests of the Amazon basin to mountain glaciers. Its isolation has protected a great diversity of wildlife including indigenous species such as the mountain tapir and Andean condor.
Threats to the Site: The Park was inscribed as endangered between 1992 and 2005 because of poaching, illegal grazing, encroachment and road building. Measures have now been taken to strengthen protection of the Park.
Sangay National Park
NATURAL WORLD HERITAGE SITE
1983: Inscribed on the World Heritage List under Natural Criteria vii, viii, ix and x.
1992-2005: Listed as a World Heritage site in Danger from poaching, roadbuilding and overgrazing .
STATEMENT OF OUTSTANDING UNIVERSAL VALUE [pending]
IUCN MANAGEMENT CATEGORY
II National Park
Amazonian / Yungas (8.05.01 / 8.35.12)
In central Ecuador 160 km south of Quito on the eastern side of the Cordillera Oriental range of the Andes. The town of Riobamba lies 20 km west and Macas 15 km southeast: 1° 27' to 2° 15'S, 78° 04' to 78° 31'W.
DATES AND HISTORY OF ESTABLISHMENT
1975: Originally gazetted as a National Wildlife Reserve (271,925 ha) under Interministry Agreement 190;
1979: Status changed to National Park under Interministry Agreement 322;
1992: The Park was almost doubled by a 245,840 ha extension to the south under Official Register 929; this is not part of the World Heritage site;
1992-2005: The site listed as endangered due to the impacts of road construction, also the heavy poaching of wildlife, illegal livestock grazing and encroachment along the Park's perimeter.
State, in Morono Santiago, Chimborazo and Tungurahua provinces. In the National Park extension, outside the World Heritage site, there are private properties. Administered by the Ministry of the Environment (M. de A., in litt., 2003), but formerly by the Sub-Secretariat of Forestry and Renewable Natural Resources (INEFAN).
World Heritage Site: 271,925 ha. Sangay National Park including southern extension: 517,765 ha.
800m to 5,319m (Altar).
The Park comprises three geomorphic zones: the volcanic High Andes, the eastern foothills and alluvial fans. The highlands, of pre-Cretaceous metamorphic and plutonic rocks, rise from 2,000-5,000m and are dominated by three stratovolcanoes: Tungurahua (5,023m) and Altar (5,319m) in the northwest and Sangay (5,230m) in the west centre of the park. All three are still active: Sangay regularly ejects hot rocks and tephra and since 1934 has been one of the world’s most continuously active volcanoes. Tungurahua violently erupted between 1916 and 1925, and has frequently erupted since 2002, disastrously, in 2006, and again in 2010. Altar has an eroded and glaciated caldera to the west, and was thought extinct until a single eruption in 2000. The eastern foothills in the north-east and south-east are low irregular mountains between 1,000m and 2,000m in height formed of outcrops of sedimentary rocks. Large east-sloping alluvial fans dominate the east side of the Park between approximately 800m and 1,300m. Younger segments of these fans are only slightly dissected, but older parts are cut into by canyons up to 200m deep (Schuerholz et al., 1980).
The High Andes zone and its volcanoes in Ecuador result from the subduction of the Nazca plate under the South American plate. It lies in the intermediate and upper Cordillera Oriental, an area of rugged topography with deep steep-sided valleys, abundant cliffs and many rocky jagged peaks. There are three subzones: subglacial, from 2,000m to 3,000m which is unglaciated; a glaciated subzone between 3,000m and 5,300m, with arêtes, cirques, and U-shaped valleys with meandering rivers, and a volcanic subzone dominated by lava and volcanic ash deposited during more recent times on the cones and flanks of the three volcanoes (Schuerholz et al., 1980).
The major rivers drain east to the Amazon Basin. From north to south these are the Llushin and its tributary Shicoyocu; Palora and its tributaries: Collones, Santa Ana, Sangay and Namoqim; and Upano and its tributaries: Volcan and Sangan. They fall with rapid and dramatic variations in level. Run-off is extremely rapid due to high rainfall and steep slopes, and erosion is substantial, although controlled by thick forest vegetation. There are numerous waterfalls, especially in the hanging valleys of the glaciated zone and along the eastern edge of the Cordillera, and many lakes, including Laguna Pintada near Altar which is 5 km long (Schuerholz et al., 1980).
Above 4,500m rocky lithosols are found in limited areas around the principal volcanoes. A thin layer of organic matter covers recent ash falls around and to the east of Sangay volcano. In the east between 3,000m and 4,500m are extensive black Andean soils of the Páramo (montane grassland) formed from volcanic base material. Black Andean soils of the cloud forest are found on the middle slopes of the Andes, in a variable north-south oriented band, particularly in areas of high rainfall and cloud cover. Moist reddish hydrolytic latosols cover much of the low eastern subtropical forest region. These are generally acid and heavily leached (Macey et al., 1976).
The Park is just south of the Equator, but being high, has a subtropical and temperate climate. Rainfall is strongly orographic. The eastern slopes of the Cordillera receive the most rainfall as moist warm air from the Amazon basin moves up over the Andes, creating a cloud forest belt. The mean annual rainfall at Pastaza, just to the northeast, is 4827mm; at Macas to the southeast, 2414mm. But the western boundary is in the rain shadow of the Western Cordillera and Penipe just beyond it has a mean annual rainfall of only 633mm. Seasonal variation is more marked to the west, with only 122 days of rain recorded in Riobamba. The wettest periods vary from site to site, generally occurring from November to February and April to October. Annual temperatures are relatively constant, although there is considerable diurnal variation. The mean annual temperature in the east is 20°C with a mean maximum and minimum of 25.4°C and 16.4°C and absolute recorded maximum and minimum of 31°C and 10°C. At the highest elevations, temperatures never rise above zero. A permanent snow line occurs at about 4,800m (Schuerholz et al., 1980).
Natural vegetation in very good condition covers 84.52% of Sangay. The Park has a high percentage of páramo, montane grassland, which has the greatest hydrological and soil carbon sequestration potential in Ecuador (IUCN, 2003). The Park lies within a WWF/IUCN Centre of Plant Diversity: at least 3,000 plant species are known to occur 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 & IUCN, 1997). The vegetation has three main zones: alpine and subalpine in the high páramo, montane cloud and wet forests, and subtropical and wet rain forests in the upper Amazon basin. (Nine life zones are detailed in the management plan.) It is principally influenced by altitude and rainfall, with the most luxuriant vegetation growing on the wetter eastern slopes.
Alpine rain tundra has formed between 4,500m and the snow line, dominated by lichens and bryophytes. A subalpine rain-páramo zone occurs between 3,400 and 4,000m, with three main vegetation types: Festuca tussock grassland; areas of cushion plants and other low-growing species, and undisturbed stands of bamboo Nuerolepsis sp. The edge of this zone has been lowered in the west by set fires. Below 3,750m montane rainforest grows on the wetter eastern slopes. The vegetation of the upper half of this zone grows about five metres high and is dominated by Polylepis tomentella, Buddleia incana, Miconia salicifolia and Myrtus communis associated with Monnina crassifolia, Baccharis teindalensis, Disphostephium lavandulaefolium and Gnoxys spp. Montane wet forest is found in the western valleys with pure stands of Polylepis 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.
Between 2,000m and 3,000m lower montane rainforest occurs on steep-sided valleys. Forests on its upper slopes are up to 12m high, dominated by Weinmania sp.and Oreopanax sp. Lower down, the canopy grows to 40m and includes Podocarpus oleofolius, red cedar Cedrela odorata (VU), Oreopanax sp., Weinmania sryadifolia and Alnus jorullensis, found in pure stands in disturbed areas. The understorey layer is formed of small trees such as Miconia sp. and a third layer of Piper ecuadorensis, Cyathea sp. and Bocconia sp. Ferns, epiphytes and orchids are abundant and towards 2,000m, Cecropia sp.,cedro Cedrela odorata, palms and Rubiaceae are present. Subtropical rainforest occurs below 2,000m, where temperatures range between 18°C and 24°C and rainfall may reach 5000mm annually. Species diversity is very high and members of the Lauraceae and Moraceae such as Ficus spp. and Chlorophora spp., palms, Cedrela odorata and wild avocado Persea sp.occur. Undergrowth species such as Selaginalla sericea and brightly coloured flowers of the Gesneraceae and Lobeliaceae are common. This formation receives less rainfall in the south, forming a subtropical wet forest, although there is no clear distinction with wetter areas. Species include Cordia alliodora, Necandra sp., Ocotea sp., Cedrela rosei, Inga sp. and Ochroma lagopus. Centropogon trachyanthus is endemic to this area. Macey et al. (1976) give partial species lists for the various formations.
The fauna is not well-studied, although it is known to be species rich. Species distributions correspond with vegetation zones and there is distinct altitudinal zonation. At the highest altitudes the Brazilian guinea pig Cavia aperea and Ecuadorian small-eared shrew Cryptotis montivaga, Andean fox Pseudalopex culpaeus, mountain tapir Tapirus pinchaque (EN)*and pumaPuma concoloroccur. Elsewhere in lower forests, spectacled bearTremarctos ornatus(VU)*, giant otter Pteronura brasiliensis (EN), jaguar Panthera onca, ocelot Leopardus pardalis, margay L. wiedii, lowland tapir Tapirus terrestris (VU), white-tailed deer Odocoileus virginianus clavium, brocket deer Mazama rufina and northern pudu deer Pudu mephistophiles, (VU) are found. A partial species list is given in Macey et al. (1976)
The Park lies within one of the world’s Endemic Bird Areas (Stattersfield et al., 1998). Some 400-500 bird species may be present, although comprehensive inventories have not yet been compiled. The 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. Among these are listed the spot-winged parrotlet Touit stictopterus (VU), redfaced parrot Hapalopsittaca pyrrhops (VU), golden-plumed parakeet Leptosittaca branickii (VU), little woodstar Chaetocercus bombus (VU), coppery-chested jacamar Galbula pastazae (VU) and masked mountain tanager Buthraupis wetmorei (VU) (Wege & Long, 1995); also reported are grey-breasted mountain-toucan Andigena hypoglauca, turquoise jay Cyanolyca turcosa, red-hooded tanager Piranga rubriceps, the purple-throated sunangel Heliangelus viola, giant humming bird Patagona gigas and Napo sabrewing hummingbird Campylopterus villaviscensio (IUCN, 2003). Other notable other species include the near-threatened Andean condor Vultur gryphus, seen particularly around the mountain area of Altar, Cubillin and Quilimas, cock of the rock Rupicola peruviana ecuatorialis, in substantial populations in inaccessible upper forest areas of the eastern Andean slopes, torrent duck Merganetta armata, king vulture Sarcoramphus papa and American swallow-tailed kite Elanoides forficatus. A preliminary species list is given in Macey et al. (1976).
Sangay National Park is one of the world’s most complex series of ecological habitats, and so far has been little altered. It lies within a C.I.-designated Conservation Hotspot, is a WWF Global 200 Freshwater Eco-region, a WWF/IUCN Centre of Plant Diversity and lies in one of the world’s Endemic Bird Areas. It received the highest resource analysis rating of any park in Ecuador. Its natural regions, terrestrial and aquatic ecosystems, physiographic formations, geology, history and other unique characteristics make it the most outstanding protected area in mainland Ecuador (FAO, 1976). It is an important protector of many watersheds, and has archaeological interest of unknown extent (WWF and IUCN, 1997).
Prior to 1534, the area was inhabited by some 30,000 Indian Huamboyas, and Indian legends are still told about the volcanoes. In the following century, the Spanish prospected for gold, began to settle the country and put down a rebellion: 19th century explorers found no inhabitants in the area. Colonisation of the eastern side started in the early 20th century (M.de A. in litt., 2003).
LOCAL HUMAN POPULATION
Much of the Park area has been inaccessible and uninhabited. The resident Indian groups are the Quichuas- Puruháes in the northwest and centre, the Quichuas-Cañaris in the south and southwest and Shuar in the south and southeast. The Quichua populations practice a subsistence economy based upon access to and use of local resources. 17 archaeological sites and potential monuments (e.g. corrals) have been located. There is a need for more detailed archaeological fieldwork in the Park and around (IUCN, 2003). However, lands to both east and west have been populated for several years now, with a number of cooperative farms close to the eastern boundary which may edge closer (Macey et al., 1976). In 1987, there were approximately 400 people living at Atilio to the southwest, 70% of whom were permanent residents (J. Thorsell, pers. comm., 1989). The area to the south added to the Park in 1992 had a resident population of about 1,000, adding to planning and management problems. There is also a noticeable increase in the presence of vaqueros and hunters in the western areas of Culebrillas and Plazapamba (INEFAN, pers. comm., 1995). The Alao area in the west is peopled by the indigenous Peruhá Amerindians (P. Catelan, 1996).
VISITORS AND VISITOR FACILITIES
The areas attracting tourists include 327 lakes and three volcanoes, though since the recent eruptions of Tungurahua, only 300-400 visit the Park annually, down from approximately 3,000 a year in 1991, since most visitors tended to stay in the Tungurahua area - which had been starting to show signs of wear (M. de A., in litt., 2003). Mountaineering on the major peaks of Tungurahua, Altar, Cubillin, Quilimas and Sangay is one of the Park's major attractions. Facilities include accommodation, hot springs, and trails (INEFAN, in litt., 1995). A tourist information centre has been built in Macas (IUCN-SUR, 1993). Since 1989 the Peruhá Association of Indigenous Guides of the Volcanoes Altar and Sanguay (ASGUIAS) has operated from San Antonio de Alao and Guargualla, the easiest access to Sangay being from the Alao valley. This indigenous organisation has been awarded professional status by the Ecuadorian Government. It offers a guide service, a dormitory and tourist shop and promotes sustainable tourism. Difficult access has tended to limit public knowledge about the Park which could be promoted more widely (P. Catelan, 1996).
SCIENTIFIC RESEARCH AND FACILITIES
A study of management alternatives by Macey et al. in 1976 examined natural, social, cultural and historic resources in the area, and reviewed alternatives such as agriculture, forestry, economic potential of minerals and management as a wildland area. The results directly led to the establishment of Sangay National Park. The 1980 management plan (Schuerholz et al., 1980) analysed biophysical, socio-economic, cultural and biological-ecological aspects of the Park to provide the foundation and justification for the different management programmes (Salazar & Huber, 1982). Research into the mountain tapir was undertaken in 1991-2, and among other subjects monitoring of the spectacled bear by the Fundacion Natura Ecosciencia is ongoing, but relatively little is known about the Park's natural resources which offer good opportunities for research (M.de A., in litt., 2003).
The management plan by Schuerholz et al. in 1980 was to be implemented over five years from 1982. Its main objectives were to protect the site's integrity through zoning, to apply appropriate management to each zone, and to define zone boundaries and launch a program of education and awareness. The main primitive and scientific zones where no human activities are permitted comprise 90% of the area. Other zones are for ecological recuperation, extensive and intensive recreational use, and administrative use. The location and activities allowed and prohibited in these zones are detailed in Macey et al. (1976). However, these zones were drawn up without community input or checking in the field. Inventories are also lacking of the Park’s biological and archaeological resources. Studies are lacking of the social-economic conditions of the local communities and stakeholder interests. And clarity over land tenure and budgetary allocations is lacking (IUCN, 2003a). A new management Plan was approved in 2005 (UNESCO, 2005).
Until recently the difficulty of access made the Park relatively easy to protect and it was under the management of the Sub-Secretariat of Forestry and Renewable Natural Resources (INEFAN). Between 1990 and 1995, with financial aid from Fundacion Natura Ecuador and technical help from the US Peace Corps, numerous facilities were built, including a tourist information centre at Macas; guard posts at Atilio and San Juan (Alao) in the west, Palora, Macas, San Isidro, Pablo Sexto, VI Cooperativa, Sinai and 9 de Octubre in the east, and Rio Negro and Candelaria in the north; shelters at El Placer hot springs and at the base of Sangay volcano. 3 of the Amazon outposts were closed in 2005 and 4 were open once a week.Trails at Pondoa (Tungurahua) and Alao (El Placer) were modified, and signs were added to trails and at Park entrances. Management equipment includes four jeeps, 11 motorcycles and six horses (INEFAN, in litt., 1995). Due to decentralisation of the Ecuadorean public sector, the Park management is headed by two managers whose offices are located at Riobamba and Macas (M.de A., in litt., 2003). The Association of Indigenous Guides of the Volcanoes Altar and Sanguay, the indigenous co-operatative, uses proceeds from tourism to finance projects to benefit their community. A new management plan is prepared, and WWF with the Ecuadorian conservation organisation Fundacion Natura, have implemented a five year conservation project funded by the Dutch government to deal with some of the issues faced by the Park such as assisting the State Party to avoid conflicts over land use and wildlife, and developing sustainable activities among the local people (UNESCO, 1999, 2004).
One of UNDP’s 2004 Equator prizes for the country went to the indigenous and campesino communities comprising the Asociación de Trabajadores Autónomos San Rafael-Tres Cruces-Yurac Rumi (ASARATY) which has, since 1999, been managing 8,000 ha of montane grassland (páramos) to counter the degradation of habitat adjacent to the Park. It has developed a participatory planning process to raise Alpacas sustainably and market products from Alpaca wool; also to increase food security, and develop income-generating ecotourism (UNDP, 2004). The Amarzaga Project of the Fundación Wanduk Yachai, aided by the Tropical Rainforest Coalition (TRC) has bought 125 ha of primary premontane rainforest in the Llushin valley just east of the Park boundary to ensure its protection. The Wanduk family which manages the Foundation from the town of Puyo nearby have also been given permission to manage 50,000 ha of rainforest within the Park itself (TRC, 2004).
The Park is most open to invasion on the east and south-east, and up the Alao valley in the west to hunters from Riobamba. Most of the subtropical lowland forest on the eastern boundary has been converted into cattle pasture and agricultural land. Overgrazing of the fragile páramo by cattle and sheep has occurred in the western areas of Filo de Plazapamba and Culebrillas Chico, resulting in extensive soil erosion and compaction. In 1987, fires burned approximately 300 ha in Naranjal Chico and 1,000 ha in Atilio destroying native vegetation (J. Thorsell, pers. comm., 1989) but the area has since recovered (M.de A., in litt., 2003).
Native animals do not yet seem to have been adversely effected by fire or introduced livestock, except in the Alao area northwest of Sangay volcano where urban poachers take mountain tapirs and deer, and the range of mountain tapir may be affected by increasing numbers of cattle. A 1996 report mentions the introduction of non-native species of trout into Rio Culebrillas, which may subsequently colonise Rio Namaquim, one of the Sangay rivers, and the upper Rio Palora (P. Catelan, in litt., 1996). Subsistence poaching occurs in the areas around Filo de Plazapamba and Altar. There has been sporadic confrontation between the residents of Atilio and Park guards, the last in 1995 (INEFAN, in litt., 1995). Both spontaneous and organised colonisation of the lower slopes of the Andes around the edge of the Park is destroying the vegetation, contributing to erosion and could threaten important watersheds. Poaching by Shuar Indians who lost most of their land to colonists migrating from the Sierras, still occurs. There are incursions into the forests along the western and southern boundaries of the Park and into the Llushin River area in the north (J. Thorsell, pers. comm., 1989).
In 1992, the site was placed on the list of World Heritage in Danger mainly because of the construction of a road by the Ministry of Public Works across the south end of the Park from Guamote in the high Andes to Macas on the plain to the southeast which divides the World Heritage site from the southern half of the Park outside it. Although the site is only crossed by the road for 8km, it was severely affected by the construction impacts: pollution of the Upana River and nearby lakes, use of dynamite, destruction of biological corridors, microclimate changes and indirect effects: new settlements, cattle ranching, poaching and logging (Wunder, 1995). However, since completion, the roadsides have begun to re-forest. This area has since been excluded from the World Heritage site. The construction also worried local people about their rights to land. The IUCN team and Park staff met opposition at the time but relations with the local people are now good (M.de A., in litt., 2003) and according to INEFAN, colonisation in the Guamboya valley and along Rio Palora and small scale mining activities have been stopped (UNESCO, 1998). There is also a potential threat of artisanal gold mining in the Llushin Grande and Huamboya areas. Effective management has been greatly hindered because of a lack of staff and too low a budget (INEFAN, in litt., 1995). Encroachment by hunters, farmers and herdsmen and unresolved conflicts over land tenure are still common. But by 2001, a UNF-funded pilot project to test the effectiveness of monitoring and management tools developed by IUCN and WCPA led to the removal of the site from the danger list (UNESCO, 2002).
Two park managers, at the Macas and Riobamba centres, three biologist/sub-superintendents, four technicians and 12 guard parks. In 1994 the Park staff was reduced by 30% because of government budgetary cuts (M.de A., in litt., 2003). Staff are still too few and ineffective to monitor the site and enforce regulations.
A budget of 120,000,000 sucres (US\$55,000) was proposed for 1995, US\$1.6 million was pledged by the government of the Netherlands, to be implemented by Fundacion Natura, the WWF, and the Nature Conservancy to help protect the Park (UNESCO, 1999). In 2002 a UNF/IUCN/UNESCO pilot study Enhancing Our Heritage was started to improve conservation and monitoring of the area. But central government funding has been severely cut back in recent years (UNESCO, 2005).
The Director, INEFAN, Junto al Ministerio de Agricultura y Ganaderia, Av. Eloy Alfonso y Amazonas, Quito, Ecuador.
The Director, INEFAN, Junto al Ministerio de Agricultura y Ganaderia, Riobamba, Ecuador.
The principal source for the above information was the original nomination for World Heritage status.
Anon. (1985). Project 1541: Sangay National Park. World Wildlife Fund Yearbook 1984/85. WWF, Gland, Switzerland. Pp. 350-351.
Catelan, P. (1996). Sangay’s Walkers: Puruhá. Draft report to WCMC.
FAO (1976). Informe Final Sobre una Propuesta Estrategia Preliminar Para la Conservacion de Areas Silvestres Sobresalientes del Ecuador. Based on the work of A.D.Putney, Working Document No.17 UNDP/FAO ECU/71/527. Ministerio de Agricultura y Ganaderia, Quito. 47 pp.
Ham, S. (1986). Review and Recommendations for Interpretive Planning, Programming and Training in Ecuador’s National Parks and Equivalent Areas. Idaho Forest, Wildlife and Range Experiment Station. Publication No. 309. University of Idaho. 9 pp.
IUCN-SUR (1993) Conservation status of Sangay National Park. IUCN-SUR, Quito.
IUCN (2003a). Report on the State of Conservation of Natural and Mixed Sites Inscribed on the World Heritage List. Gland, Switzerland
--------- (2003b). Review of Initial Assessment: Sangay National Park, Ecuador. Enhancing Our Heritage pilot study.
Macey, A., Armstrong, G., Gallo, N. & Hall, M. (1976). Sangay: a Study of Management Alternatives. World Wildlife Fund. UNDP/FAO ECU/71/527. Quito, Ecuador. 94 pp.
Salazar, A. & Huber, R. (1982). Ecuador's active conservation program. Parks 6 (4): 7-10.
Schuerholz, G., Pancar, A. & Huber, R. (1980). Plan de Manejo del Parque Nacional. World Wildlife Fund / FAO. Quito, Ecuador.
Stattersfield, A. et al. (1998). Endemic Bird Areas of the World: Priorities for their Conservation. BirdLife International, Cambridge, U.K.
UNESCO World Heritage Committee (1998). Report on the 21st Session of the Committee, Paris.
---------- (1999). Report on the 22nd Session of the Committee, Paris.
---------- (2002). Report on the 25th Session of the Committee. Paris.
---------- (2004). Report on the 28th Session of the Committee. Paris.
---------- (2005). Report on the 29th Session of the Committee. Paris.
Wege, D. & Long, A. (eds) (1995). Key Areas for Threatened Birds in the Neotropics. BirdLife International, Cambridge, U.K. BLI Conservation Series No.5.
Wunder, S. (1995). Conservation Status of Sangay National Park with Special Emphasis on the Guamote-Macas Road. Report to the UNESCO World Heritage Committee. 27 pp.
WWF & IUCN (1997). Centres of Plant Diversity. A Guide and Strategy for their Conservation. Vol.3: The Americas. IUCN Publications Unit, Cambridge, UK.
December 1982. Updated 5-1989, 9-1989, 7-1995, 7-1997, 4-2002, 10-2006, 11-2010, May 2011.