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BRAULIO CARRILLO-LA SELVA REGION
Located in Heredia, San José, Cartago and Limón provinces of central Costa Rica, the c. 500 km² region includes La Selva Biological Station (15.6 km²) at the western edge of the Atlantic lowlands (55 km from the coast), and Braulio Carrillo National Park (465-475 km²). The station is c. 4 km south of Puerto Viejo de Sarapiquí - the limit of navigation from the Caribbean Sea on the Sarapiquí River, at the junction of the flat lowlands and the foothills, which ascend south-westward to Cacho Negro (2150 m) and Barva (2906 m) volcanoes.
The somewhat boot-shaped park has its largest portion in the highlands of the Central Volcanic Cordillera; 30 km to the south-west is the populous Central Valley (Meseta Central) and capital San José. The lower La Selva sector of the park, from 850 m downslope to the station in the north (at c. 135-35 m), is a narrow corridor (18 km × 4-6 km) mainly of primary rain forest lying between the Peje and Guácimo rivers. Virtually the entire watersheds of these rivers are within the park, and the upper watersheds of the Puerto Viejo and Sucio rivers are in the park highlands, which are strongly dissected, with deep valleys and many waterfalls. Barva Volcano is composed of several craters, now including the crystal-clear Barva Lake (70 m across) and Danta Lake (500 m across).
This region comprises what may be the most extensive altitudinal range (2871 m) of primary tropical forest protected in Central America (Pringle et al. 1984; Hartshorn and Peralta 1988; Pringle 1988). In the southern half of the station and farther south in the park's narrow La Selva sector, soils appear to be derived from andesites and basalt. At 2000 m some soils seem to be derived from ash, whereas at 2600 m near Barva Volcano there are considerable deposits of granular andesitic ash. With increasing elevation organic matter increases, and above 1400 m humus accumulates (Hartshorn and Peralta 1988; Pringle 1988). Landslides are common on steep slopes especially at the mid-elevations.
At La Selva station, annual rainfall averages c. 3962 mm (up to 150 mm have fallen in one day). The mean monthly air temperature is c. 25.8°C (varying annually by less than 3°C), with a diurnal range of 6°-12°C; the known daily maximum (in May) is 36.6°C, the known night-time minimum (in March) 16°C. At 1500-1800 m, the annual average precipitation could be 6000 mm; rainfall in the park may average 4500 m. Trade winds can be strong; a windstorm in June 1986 destroyed 1.5-2 km of primary forests between 1100-1300 m. The wettest months are July and December, and somewhat less rain falls in February-April (the drier season) and perhaps September (the "veranillo"). During the drier season, intervals average c. 12 days between total daily rainfalls of more than 5 mm, although in 1983 there was an interval of 30 days without such precipitation.
The region is within four Holdridge life zones and two transitional areas; c. 75% of the park-station region is in the premontane and lower montane zones. Much more is known about the vegetation of the station than the connecting corridor or the more rugged, large upland portion of the park (CCT 1975; Boza and Mendoza 1981; Janzen 1983; Boza 1988; Hartshorn and Peralta 1988; McDade et al. 1994). Perhaps 75% remains in mature forest, and most of the rest has reverted to patches of secondary growth 6-25 or more years old.
1. The area of La Selva Biological Station is within the tropical wet-forest life zone. The station encompasses a variety of terrestrial and aquatic habitats - e.g. ridge and coastal plain forests, swamps, and riparian ecotones. In the mature forests Pentaclethra macroloba predominates, a canopy tree to 30-40 m. Other abundant canopy trees include Apeiba membranacea, Brosimum lactescens, Goethalsia meiantha, Laetia procera and Pourouma bicolor subsp. scobina (P. aspera). There may be over 30 palm species, which are strikingly abundant, such as the very common subcanopy palms Welfia georgii, Socratea durissima (S. exorrhiza) and Iriartea deltoidea (I. gigantea). In the understorey Asterogyne martiana and Asplundia uncinata are conspicuous. In swamp forest the characteristic, long-lived Carapa guianensis (C. nicaraguensis) (to 45 m tall and 2 m dbh) occurs in increased abundance, along with Pterocarpus officinalis (Hartshorn 1983; Clark 1988; Hartshorn and Peralta 1988; Pringle 1988; Lieberman et al. 1990).
2. Tropical wet forest - cool transition occurs at 250-600 m, commencing where Pentaclethra macroloba abruptly loses dominance. Other characteristic trees are Euterpe macrospadix, Billia columbiana, Calophyllum brasiliense var. rekoi, Micropholis crotonoides and Vochysia ferruginea. Subcanopy and understorey palms are less frequent.
3. At 600-800 m occurs tropical premontane rain forest - perhumid transition, where in addition to the three preceding species, Alchornea latifolia (which extends from 300-2300 m) and Macrohasseltia macroterantha become characteristic. The abundant lowland palm Prestoea decurrens reaches its limit in this belt.
4. The tropical premontane rain-forest life zone occurs between 800-1450 m. Prominent in the canopy are species of Lauraceae and Sapotaceae, together with Hyeronima guatemalensis and Meliosma vernicosa. A few lowland trees reach the upper limit of this zone, e.g. Dendropanax arboreus, Dussia macroprophyllata and Pterocarpus rohrii (P. hayesii). Palms continue to decline; Prestoea longepetiolata occurs at 1000-1400 m. Tree ferns increase markedly (e.g. species of Cyathea, Cnemidaria, Dicksonia).
5. The change to the distinctive tropical lower montane rain-forest zone (1450-2500 m) occurs gradually at the frost belt (1300-1600 m), above which brownish epiphytic mosses and the clambering understorey bamboo Chusquea pohlii are conspicuous. There are few palm species; Prestoea allenii and Geonoma interrupta are abundant. Typical trees include Billia hippocastanum, Guatteria oliviformis, Hyeronima poasana, Ocotea austinii, Quercus tonduzii and Turpinia occidentalis. In both of the montane zones occur Alnus, Cornus, Magnolia, Prunus, Symplocos, Viburnum and Podocarpus.
6. In the tropical montane rain-forest zone (2500-2906 m), characteristic trees are Brunellia costaricensis, Didymopanax pittieri, Drimys winteri, Ilex vulcanicola, Quercus costaricensis and Weinmannia pinnata. The canopy is about half as high (20-23 m) as at the station.
A checklist of the vascular plants of La Selva station is being maintained (Wilbur et al. 1994); in 1986, publication of the families began toward production of a complete Flora (see Hammel 1990), which may cover 1900-2200 species. The flora is rich in epiphytes and hemi-epiphytes, which make up 25% of the species, the majority being orchids (114 spp.), aroids and ferns. Over 460 species of trees are known from the station. A 1983 preliminary inventory of the park's La Selva sector (most of the former Zona Protectora) identified c. 200 tree species; 800 might occur in the entire park-station region, which is 40% of the tree species estimated for the entire country (Janzen 1983; Pringle 1988). Included is a recently discovered family of trees (Ticodendraceae). The phytogeographic affinities of the lowland flora are mostly with Panama and northern South America. Perhaps 10% of the lowland flora is regionally endemic.
La Selva sector forests may be essential habitat for at least 75 tree species in many families, together with some species new to science; 34 of those rare trees are named in Pringle et al. (1984). Documented rare herbaceous and understorey species occurring in this corridor (some known from the station, but otherwise unknown or seldom found in Costa Rica) include Danaea carillensis, Justicia sarapiquensis, Philodendron rigidifolium, Potalia amara and Xylopia bocatorena. At least 16 other species that are rare in Costa Rica occur in the corridor but are unknown from the station. During a just 10-day reconnaissance of the corridor in 1983 (Pringle et al. 1984; Pringle 1988), at least 28 plant species new to science and 12 new to Costa Rica were discovered, including the rare fern Thelypteris valdepilosa previously known only from Colombia, and Reedrollinsia (known in southern Mexico). Some 4000-6000 plant species may occur in Braulio Carrillo National Park (Boza 1988; Clark 1990).
La Selva sector has species of economic, including genetic-resource, importance (e.g. the rare Monstera deliciosa; Vanilla pauciflora; two species of Theobroma). Some of the region's c. 56 reported palm species may be used for the vegetable palm hearts or are ornamental - e.g. Geonoma epetiolata, Chamaedorea pumila and C. amabilis. In the cool transition belt some valuable timber species are much more common than at the station - Aspidosperma megalocarpon (A. cruentum), Calophyllum brasiliense var. rekoi, Dalbergia tucurrensis, Hyeronima oblonga, Lecythis ampla and Minquartia guianensis (Hartshorn and Peralta 1988). Alnus acuminata (which reaches Mexico) is an important upland timber species not found farther north in Costa Rica (Janzen 1983).
Social and environmental values
The Braulio Carrillo National Park-La Selva region, together with other reserves that form the Central Volcanic Cordillera Biosphere Reserve, protects three sizeable watersheds of the Sarapiquí, Sucio and Chirripó rivers (MAB 1988; Pringle 1988). A panoramic major highway linking San José to Guápiles and the Caribbean port of Limón crosses through the park; it opened in 1987 (CCT 1975; Wallace 1992). The park (Boza 1988) is visited by an increasing number of tourists - over 500,000 in 1993 - including many international visitors.
The region forms a portion of two Endemic Bird Areas (EBAs A18 and A16). The relatively small highland region of Costa Rica and western Panama is home to an incredible 52 restricted-range bird species, many of which occur in the NP; c. 13 such species occur in the tropical wet forest of the Caribbean lowlands. Among the region's over 142 mammal species are 3 monkey species, 5 cat species and Baird's tapir (Tapirus bairdii) (Timm et al. 1989; Wilson 1990). The 87 known reptile species include 2 crocodilian and 56 snake species; there are 44 species of frogs (Guyer 1990). Over 4000 moth species and 500 butterfly species are estimated to be present.
La Selva Biological Station (picture) has become one of the best known neotropical sites, an investment in environmental research (summarized in McDade et al. 1994) that demonstrates the natural wealth in the region. At least 412 bird species have been reported from La Selva and nearby areas, including 75-80% of Costa Rica's land birds and 256 breeding species; c. 10% migrate from North America to winter within the complex, and c. 20% migrate altitudinally within it - probably responding to the availability of fruits and flowers (nectar) (Pringle 1988; Stiles 1988). The complex is particularly important in this respect - it is one of few protected forest areas that caters for species such as the threatened bare-necked umbrellabird (Cephalopterus glabricollis), which winters in tropical lowlands and breeds in montane rain forests.
In 1980, La Selva Biological Station and the adjacent natural lands were recommended by the U.S. National Research Council as one of just four areas in which to concentrate tropical ecosystem studies. Between 1979 and 1986 the station gained 24-hour electricity from the national grid and convenient access by paving of the highway to Puerto Viejo, completion of an all-weather road to the east bank of the Puerto Viejo River and construction of a 100-m pedestrian suspension bridge to the station property. The 1953 Finca La Selva was on a remote frontier, only accessible by canoe, after a drive of very many hours on a tortuous road from San José; in 1993, the research station became just 1¼ hours away by paved highway. Also in the 1980s, the infrastructural facilities for research, teaching and environmental education were greatly improved.
Research includes (for example) systematics, evolutionary ecology, forest dynamics (e.g. Lieberman et al. 1990) and life-history studies of timber trees, and water, soil and nutrient processes in natural, disturbed and abandoned areas. Over 80 species of timber trees have been evaluated for usefulness in reforesting degraded soils; a dozen species have been chosen for use in farm forestry in the area, which makes the conservation of their germplasm particularly significant. Discovery of charcoal in soil cores from several areas of La Selva mature ("primary") forest initiated a project which is evaluating the influence of aboriginal peoples on the region's vegetation, from c. 3000 BP onward (Clark 1988, 1990; McDade et al. 1994).
The general region was transformed from connected forest to an ecological island between 1961 and 1977 (Gámez and Ugalde 1988). The area of La Selva station was largely surrounded by forest in 1965, but cattle pasturage and family farms now border the station except to the south (Greene 1988; Wallace 1992; Kohl 1993; Butterfield 1994). The station area is 56% primary forest, 18% high-graded and secondary forest and c. 25% early successional pastures, abandoned plantations and managed areas (Clark 1990). The 18-km long La Selva sector of the park (most of the former Zona Protectora), being a corridor only 4-6 km wide, may be too narrow to maintain some natural processes as it becomes even more isolated by forest conversion outside it (Greene 1988; Hartshorn and Peralta 1988; Pringle 1988; Stiles 1988). In 1983 the corridor was 73% primary forest, 10% mainly secondary forest, 16% patches of pasture and 1% crops (Pringle 1988). Since the majority of the Zona Protectora became part of the park in 1986, illegal logging and squatters have not been continuing problems, but poaching does occur (cf. Clark 1988). In c. 1981 the park highlands (320 km²) were 84% primary forest, 5% secondary forest and 11% ranches and farms in alluvial valleys (Boza and Mendoza 1981).
Finca La Selva began in 1953 when Dr L.R. Holdridge purchased the Costa Rican homestead. The station (6.13 km²) was established in 1968 with its purchase by the Organization for Tropical Studies (OTS) (Stone 1988), and has since been expanded to 15.6 km². The highlands majority of the park (314-320 km²) was established in 1977-1978, having been prompted by the planned highway through the region (Boza and Mendoza 1981; Wallace 1992). La Selva Protection Zone (73.68 km² including the station) was declared in 1982 to create a natural corridor between the lowland station and upland park (Stone 1982). After extensive cooperation and fund-raising, the Peje sector (135 km² - the Zone, except for the station, plus a portion of the Central Volcanic Cordillera Forest Reserve) was incorporated into the park in 1986, and most private land within that 3-6 km wide Zone had been purchased by 1989 (Pringle 1988). In 1990 an additional narrow strip of 20 km² along the western border of the narrow La Selva sector was declared parkland; by October 1993, its purchase was c. 60% complete. Funds were raised by OTS, The Nature Conservancy (U.S.A.) and the World Wildlife Fund - U.S. working with Costa Rica's Fundación de Parques Nacionales, which maintains an integral function in assisting programmes of land purchase, protection and environmental education. Also, four private reserves totalling 14.22 km² are situated near the park-station complex (Butterfield 1994).
The government in 1987 through the National Parks Service began to integrate park management and community outreach in nine regional Conservation Areas (ACs), merging key protected areas and adjacent areas into units within a National System of Conservation Areas (SINAC). The Central Volcanic Cordillera AC (Map 27) combines the Braulio Carrillo-La Selva region (picture) with Volcán Poás National Park (56 km²), Volcán Irazú NP (23 km²) and the bordering Central Volcanic Cordillera Forest Reserve (910 km²) (Brandon and Umaña 1991). The entire complex (c. 1464 km²) has been recognized by UNESCO as the Central Volcanic Cordillera Biosphere Reserve (MAB 1988; Butterfield 1994). FUNDECOR, a regional non-governmental organization with a mandate to foster conservation and buffer-zone management of the BR, was established in 1989 with U.S. Agency for International Development financing, including an endowment.
The Organization for Tropical Studies facilitates education, research, and wise use of natural resources through a consortium of over 50 universities and institutions from U.S.A., Puerto Rico, Honduras and Costa Rica (Stone 1988; Clark 1990; Schnell 1993, pers. comm.). Efforts at La Selva Biological Station in research for ecodevelopment and in environmental education are expanding (Clark 1988, 1990; Kohl 1993; McDade et al. 1994). Investment in agency, institutional and human resources is increasing in Costa Rica and becoming well recognized as essential - so that protection and management of the park region may be lasting, with help from a carefully tailored institutional framework and its endowment, as pressures intensify with population growth (Clark 1988, 1990; Gámez and Ugalde 1988; Gómez 1988; Hartshorn and Peralta 1988; Stone 1988; Wallace 1992).
Map 27. Braulio Carrillo-La Selva Region, Costa Rica (CPD Site MA16)
Boza, M.A. (1988). Parques nacionales Costa Rica national parks. Editorial Heliconia and Fundación Neotrópica, San José. 271 pp.
Boza, M.A. and Mendoza, R. (1981). The national parks of Costa Rica. Incafo, Madrid. 310 pp.
Brandon, K. and Umaña, A. (1991). Rooting for Costa Rica's megaparks. Américas 43(3): 20-31.
Butterfield, R.P. (1994). The regional context: land colonization and conservation in Sarapiquí. In McDade, L.A., Bawa, K.S., Hespenheide, H.A. and Hartshorn, G.S. (eds), La Selva. University of Chicago Press, Chicago. Pp. 299-306.
CCT (1975). Estudio sobre bases ecológicas y legales para establecer medidas de protección y control a los bosques y aguas de la zona de influencia de la carretera San José-Guápiles. Centro Científico Tropical (CCT), San José.
Clark, D.B. (1988). The search for solutions: research and education at the La Selva station and their relation to ecodevelopment. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests: diversity and conservation. California Academy of Sciences and American Association for Advancement of Science (AAAS) Pacific Division, San Francisco. Pp. 209-224.
Clark, D.B. (1990). La Selva Biological Station: a blueprint for stimulating tropical research. In Gentry, A.H. (ed.), Four neotropical rainforests. Yale University Press, New Haven. Pp. 9-27.
Gámez, R. and Ugalde, A. (1988). Costa Rica's national park system and the preservation of biological diversity: linking conservation with socio-economic development. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 131-142.
Gómez, L.D. (1988). The conservation of biological diversity: the case of Costa Rica in the year 2000. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 125-129.
Greene, H.W. (1988). Species richness in tropical predators. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 259-280.
Guyer, C. (1990). The herpetofauna of La Selva, Costa Rica. In Gentry, A.H. (ed.), Four neotropical rainforests. Yale University Press, New Haven. Pp. 371-385.
Hammel, B.E. (1990). The distribution of diversity among families, genera, and habit types in the La Selva flora. In Gentry, A.H. (ed.), Four neotropical rainforests. Yale University Press, New Haven. Pp. 75-84.
Hartshorn, G.S. (1983). Plants: introduction. Site descriptions: La Selva. In Janzen, D.H. (ed.), Costa Rican natural history. University Chicago Press, Chicago. Pp. 136-140.
Hartshorn, G. and Peralta, R. (1988). Preliminary description of primary forests along the La Selva-Volcán Barva altitudinal transect, Costa Rica. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 281-295.
Janzen, D.H. (ed.) (1983). Costa Rican natural history. University Chicago Press, Chicago. 816 pp.
Kohl, J. (1993). No reserve is an island. Wildlife Conserv. 96(5): 74-75, 82.
Lieberman, D., Hartshorn, G.S., Lieberman, M. and Peralta, R. (1990). Forest dynamics at La Selva Biological Station, Costa Rica, 1969-1985. In Gentry, A.H. (ed.), Four neotropical rainforests. Yale University Press, New Haven. Pp. 509-521.
MAB (Man and the Biosphere Programme) (1988). La Selva Biological Station designated as part of a Central Volcanic Cordillera Biosphere Reserve in Costa Rica. MAB Bull. 12(1): 6.
McDade, L.A., Bawa, K.S., Hespenheide, H.A. and Hartshorn, G.S. (eds) (1994). La Selva: ecology and natural history of a neotropical rainforest. University Chicago Press, Chicago. 486 pp.
Pringle, C.M. (1988). History of conservation efforts and initial exploration of the lower extension of Parque Nacional Braulio Carrillo, Costa Rica. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 131-142.
Pringle, C.M., Chacón, I., Grayum, M.H., Greene, H.W., Hartshorn, G.S., Schatz, G.E., Stiles, F.G., Gómez, C. and Rodríguez, M. (1984). Natural history observations and ecological evaluation of the La Selva Protection Zone, Costa Rica. Brenesia 22: 189-206.
Stiles, F.G. (1988). Altitudinal movements of birds on the Caribbean slope of Costa Rica: implications for conservation. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 243-258.
Stone, D.E. (1982). Conversion of Zona Protectora "La Selva" into an extension of Braulio Carrillo National Park, Costa Rica. Proposal to WWF-US (15 Oct.). Organization for Tropical Studies. 5 pp. + 3 appendices.
Stone, D.E. (1988). The Organization for Tropical Studies (OTS): a success story in graduate training and research. In Almeda, F. and Pringle, C.M. (eds), Tropical rainforests. Calif. Acad. Sci. and AAAS Pacific Division, San Francisco. Pp. 143-187.
Timm, R.M., Wilson, D.E., Clauson, B.L., LaVal, R.K. and Vaughan, C.S. (1989). Mammals of the La Selva-Braulio Carrillo complex, Costa Rica. North Amer. Fauna 75. 162 pp.
Wallace, D.R. (1992). The quetzal and the macaw: the story of Costa Rica's national parks. Sierra Club Books, San Francisco, Calif. 222 pp.
Wilbur, R.L. and collaborators (1994). Vascular plants: an interim checklist. In McDade, L.A., Bawa, K.S., Hespenheide, H.A. and Hartshorn, G.S. (eds), La Selva. University Chicago Press, Chicago. Pp. 350-378.
Wilson, D.E. (1990). Mammals of La Selva, Costa Rica. In Gentry, A.H. (ed.), Four neotropical rainforests. Yale University Press, New Haven. Pp. 273-286.
This Data Sheet was written by Olga Herrera-MacBryde (Smithsonian Institution, SI/MAB
Program, S. Dillon Ripley Center, Suite 3123, Washington, DC 20560-0705, U.S.A.).
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