The Biological Importance of La Cangreja

Quírico Jiménez M.

The national park La Cangreja in southern Puriscal County is a biological paradise of special importance as the last remnant of the species-rich forests of the region. La Cangreja has a varied topography, including the transition between very wet and pre-montane rainforests, a precipitation that exceeds 4,000 mm annually, high humidity, and poor soils. As a result, it boasts an extremely diverse flora and a high rate of endemism. Prior to 1993, approximately 800 species of flora were identified. An impressive number of species could yet be discovered, as the group of small plants such as ferns, araceas, orchids, bromelias, grasses, and vines have barely been collected, let alone studied. Undoubtedly, more than 2,000 species of plants could exist at the site. In the last few years, various new tree species have been discovered in La Cangreja, some of which are endemic to Costa Rica and found only in this Protected Zone. Plinia puriscalensis (Myrtaceae), named in honor of Puriscal County, and Ayenia mastatalensis (Sterculiaceae), named after the community of Mastatal near La Cangreja, are two such species. Both of these small trees are numerous in the Zone, but if they disappear from there, they will be lost forever. 

Various other tree species, endemic to Costa Rica as a whole, were identified for the first time in La Cangreja. Caryodapvhnopsis burgeri (Lauraceae), discovered in La Cangreja and later collected in Golfito and the Osa Peninsula, is known as the only Lauraceae in the country with opposite leaves. The genus Caryodaphnopsis, a genus of the Philippines with three species in South America and one in Central America, was first identified for Central America in La Cangreja. Unfortunately, this tree is in grave danger of extinction. Therefore, it is considered a "living fossil," as its wood has been used for years in the region.

The species Unonopsis theobromifolia (Annonaceae) is another new species endemic to La Cangreja, the Carara Biological Reserve, and the Osa Peninsula, and fortunately, this small tree is fairly common in all these locations. Ternstroemia multiovulata, of the family Theaceae, is a species of which two known locations are La Cangreja and the Osa Peninsula. The small, scarce tree Peltostigma guatemalense (Rutaceae) is another species first found in La Cangreja. Rutaceae also exists in the Cordillera Volcánica, a
mountain range in the Northwestern province of Guanacaste. La Cangreja also contains seventeen species of timber trees which are often used commercially in Costa Rica.

The following nine of these seventeen are threatened or endangered species because of the over-exploitation they have suffered: Tachigalia versicolor (plomo), Caryocar costarricense (butternut), Caryodaphnopsis burgeri (quira), Tabebuia guayacan (guayacan, corteza), Astronium graveolens (gonzalo alves), Peltogyne purpurea (purple heart), Couratari guianensis (cachimbo), Platymiscium pinnatum (Panama redwood), and Myroxylon balsamum (balsam). Many of these woods, such as purple heart, Panama redwood, and gonzalo alves are fine woods used principally in crafts and cabinetry.

Other, more common timber trees found in La Cangreja are Bombacopsis quinatum (spiny cedar) and Cordia alliodora (laurel). Both are rapid-growth species often used in Costa Rican reforestation projects. Also found are Cedrela odorata (cedar), Simarouba amara (olive), Vochysia ferruginea (botarrama), Carapa guianensis ( crabwood), Ceiba pentandra ( ceiba), Tabebuia rosea (roble sabana), Schizolobium parahybum (quamwood), Hieronyma alchorneoides (bully tree), Virola koschnyi (banak), Terminalia oblonga (sura), Terminalia
amazonia (roble coral), and Calophyllum brasiliense (Santa Maria). The majority of these species produce high-quality woods used to construct furniture, doors, frames, floors, and paneling.

 La Cangreja also possesses species widely used for their medicinal properties. Infusions of the wood of Quassia amara (big man/hombre grande) and Neurolaena lobata (gavilana) leaves are used against digestive ailments, and an infusion from Simarouba amara (olive tree bark) fights intestinal parasites, especiallyamoebas. The vine known as Bauhinia manca (monkey's ladder/escalera de mono) has been
employed against diabetes, and the Mikania guaco (guaco ) vine is being studied as an antidote for poisonous snake venom.

Unfortunately, hunting has greatly reduced the Zone's animal species. The area is too small to provide the space to sustain large  mammals, and as a result, the only large mammals observed margays, deer, tolumucos. Other animal species in the Zone are: Didelphis marsupialis (zorro pelon), Cebus capucinos (white-faced capuchin monkey), Choloepus hoffinannii (2-toed sloth), Dasypus novemcinctus (armadillo), Sylvilagus floridanus (rabbit), Sciurus variegatoides (squirrel), Canis latrans (coyote), Procyon lotor (raccoon), Agouti paca (agouti), Mustela frenata (weasel), and Nasua nasua (pizote).

Although the area includes a wide variety of bird species, some find themselves threatened or endangered as their habitat is rapidly disappearing, Such is the case for Tinamus major (gongolona or mountain hen), Procnias tricarunculata (calandria or bell bird), Pteroglosus frantzii (fiery-billed aracari), Dendroica petechia (reinita), Lopostrix cristata (esucurú), and Caroodectes antionae.
La Cangreja represents the last patch of natural, unaltered forest left in all the county of Puriscal, with vegetation similar to that of Corcovado National Park in the Osa Peninsula, but with a relatively high rate of 5-8% endemism, The site offers an excellent germoplasm bank with rare, endemic, and endangered species.

Seeds could be harvested from these species for reproduction in a nursery for timber trees that could be used in reforestation projects with native species. The potential value of this small patch of forest is impossible to calculate, given that its species, whose chemistry has not yet been studied, could possibly cure some of the worst diseases known to humankind.

Besides its own intrinsic value, La Cangreja is a place where nature still maintains its complex, evolving system, The fragile equilibrium of its ecosystem is in danger of extinction, not only in the county of Puriscal, but throughout the world. This gives it special ecological importance. If we lose the opportunity to protect it right now, we will undoubtedly lose it forever.

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