Costa Rican Ecosystems

The University of Chicago Press

Costa Rica's Ecosystems: Setting the Stage

Maarten Kappelle

We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.

— Edward O. Wilson, Professor Emeritus, Harvard University

No other area of equal size anywhere in America possesses so rich and varied flora, and none in North America is at all comparable in these respects. It is improbable that in any part of the Earth there can be found an equal area of greater botanical interest. ... In few countries of the world, I believe, would it be possible to travel so much and find only pleasant and ever varied scenes, and be received everywhere with simple and sincere hospitality.

— Paul C. Standley, in Flora of Costa Rica, October 12, 1937

Ecosystem Discovery, Exploitation, Conservation, and Sustainability

Some twenty years after Christopher Columbus visited in 1502 the coast of today's Puerto Limón on his fourth and final voyage to the New World, the Spanish conquistador Gil González D'Ávila, while on a royal expedition sailing from Panama to Nicaragua, named the country Costa Rica, or Rich Coast. He did so because of the golden objects that were used by pre-Columbian indigenous tribes for body decoration and rank distinction, including necklaces, nose plugs, ear plugs, bracelets, and bells (Quilter and Hoopes 2003). However, ultimately it was not the golden treasures that justified the name of Costa Rica, but rather its biological richess: its huge variety of life, piled up in a small corner of the world (Gómez and Savage 1983). Ever since foreign naturalists like Anders Sandoe Ørsted, William More Gabb, Karl Sapper, Karl Hoffmann, Alexander von Frantzius, Karl Wercklé, and Henri François Pittier visited the country and were astonished by its rich flora and fauna, Costa Rica and its ecosystems have been considered by specialists and laymen a true Valhalla of biotic diversity in all its senses (Pittier 1908, Gómez and Savage 1983, Hartshorn 1983, Gómez 1986).

However, over the past 150 years Costa Rica's lush ecosystems have become more and more threatened, pricipally as a result of land conversion for cattle ranching, coffee growing, and large-scale banana production (Hall 1985). Particularly since World War II when the interest in precious hardwoods increased and construction of highways flourished (Merker et al. 1943), accelerated deforestation became the prime driver of biodiversity loss in the country (Sader and Joyce 1988). During the past few decades forest conversion together with other stress factors — such as climate change, overfishing, the introduction of aggressive invasive alien species, the construction of large infrastructure features such as roads and dams, sedimentation, environmental pollution, urban sprawl, and coastal encroachment — have begun to put ever-increasing pressures on the fragile cornucopia of Costa Rica's ecological systems, impoverishing and reshaping them in already fragmented landscapes and seascapes.

While during the second half of the twentieth century Costa Rica lost almost half of its forest cover, since the early 1970s to date (2015) the country has been able to save millions of hectares in 169 protected areas, ranging from absolute reserves and national parks to forest reserves and protective zones (Gámez and Ugalde 1988, Boza 1992, Wallace 1992, SINAC 2009, Obando 2011). Together, Costa Rica's protected areas cover 26.2% of the country's territory today. The development of the national park system initially occurred simultaneously with massive deforestation in unprotected areas, a phenomenon now known as the "Grand Contradiction" (Evans 1999).

The first wildlife area that received formal protection was created in 1945. It concerned the montane oak forest zone just south of Cartago, along both sides of the Inter-American Highway (Kappelle 1996). From 1969 to the late 1970s this and other early protected areas, including the Reserva Natural Absoluta Cabo Blanco and the Volcán Turrialba and Volcán Irazú national parks, were formally administered by the Departamento de Parques Nacionales. Then in 1977, protected area management passed on to the Servicio de Parques Nacionales (SPN), which was formally created as a specialized unit under direction of the Ministerio de Agricultura y Ganadería (MAG). Key protected areas like the now famous Cahuita, Chirripó, Corcovado, Santa Rosa, and Tortuguero national parks were created during that decade, as the environmental movement became stronger and focused hard on safeguarding the country's last remaining wild places (Gámez and Ugalde 1988, Wallace 1992, Boza 1993).

At the end of the next decade, in 1988, SPN was incorporated into the new Ministerio de Recursos Naturales, Energía y Minas (MIRENEM). Then, in 1995, new responsibilities were added while MIRENEM was restructured. It became the Ministerio del Ambiente y Energía (MINAE). In that same year, SPN was merged with both the Dirección General Forestal (DGF) and the Dirección General de Vida Silvestre (DGVS) into the innovative Sistema Nacional de Áreas de Conservación (SINAC), a subdivision of the young MINAE (Evans 1999). During the second administration of President Oscar Arias Sánchez (2006 to 2010) the telecommunications sector was added to MINAE, to become the Ministerio del Ambiente, Energía y Telecomunicaciones (MINAET). In 2013 MINAET became again MINAE, as the telecommunication department was moved to another ministry. As of 2014, MINAE is also referred to as the Ministerio del Ambiente, Energía, Aguas y Mares, recognizing the growing importance of the freshwater and marine resources for the country.

SINAC was foremost created to serve as a facilitating mechanism necessary to administer all protected areas in an integrated manner at regional level (SINAC 2009). In total, eleven Áreas de Conservación (ACs) were established as part of SINAC, covering the full territory of the country. Costa Rica's 1998 biodiversity law (Ley de Biodiversidad) legally formalized and strengthened this organizational structure and its holistic, decentralized, and inclusive approach.

Thanks to extraordinary efforts in the past, Costa Rica has now been able to devote nearly a third of its territory to the conservation into perpetuity of its rich biological diversity, spread over eleven conservation areas (for a more detailed historical account, see Wallace 1992, García 1997, Evans 1999, and Gámez 2003). Therefore, today Costa Rica serves as a successful model of biodiversity research and conservation. It is a country in which many innovative ideas were first conceptualized, tested, and implemented (Fournier 1991, Wallace 1992, Evans 1999). These ideas range from all-taxa biodiversity inventories (ATBI) (Janzen and Gámez 1997) and biological prospecting meant to discover wild species with medicinal properties (Tamayo et al. 2004) to avant-garde bar-coding of plant and insect specimens in ex situ collections (Gámez 1999); from an out-of-the-box means of linking debt reduction with environmental protection measures through Debt-for-Nature Swaps proposed by Tom Lovejoy in 1984 (Thapa 1998) to revolutionary Payments for Environmental Services (PES; Pagiola 2008, and see Arriagada et al. 2012); and from ecosystem-based sustainable tourism models (Aylward et al. 1996) to leadership in climate change discussions (Castro et al. 2000), mostly recently about Reduced Emissions from Deforestation and forest Degradation (REDD and REDD+; Karousakis 2007). Hence, since the early 1970s Costa Rica has been at the forefront in developing and implementing new and bold ideas to study and safeguard its extraordinary biodiversity.

Over the coming decades, such novel approaches will allow the country to catalyze its human sustainable development model based on twenty-first-century principles of a truly green economy. In this context it is important to mention that Costa Rica has announced its intention to become the first carbon dioxide–neutral country in 2030. Another very hopeful sign is the fact that Costa Rica has recently recorded a change from having a net loss of forests to having a net gain in forest area (UNEP/GRID-Arendal 2009): while in 1991, 29 percent (ca 14,000 km2) of Costa Rica's land cover qualified as closed forest (Sánchez-Azofeifa et al. 2006), by 2010 thanks to forest-related interventions up to 51 percent of its land area could be classified again as closed forest (UNEP/GRID-Arendal 2009, Stone 2011) — a unique success story at global level!

History of Costa Rica's Biogeography

To understand the diversity and complexity of Costa Rica's ecosystems today, it is essential to get a grasp of their biogeographic history. When did these ecosystems actually originate and how did they develop over time? As Coates and Obando (1996) discussed in their treatment of the geologic evolution of the Central American Isthmus, its formation has indeed been a complex and extended process that stretched over the last 15 million years and had huge consequences to ocean circulation, global climatic patterns, biogeography, ecology, and the evolution of both terrestrial and marine organisms in the region (also, see Jones and Hasson 1985, and Stehli and Webb 1985). Today the rise of the isthmus is considered to be the culmination of an extended geologic history involving the growth and migration of the Central American volcanic arc, at the junction of the Pacific and Caribbean Plates, and its collision with South America (Coates and Obando 1996).

The formation and closure of the Central American land bridge about 2.7 million years (Ma) triggered the migration of plants and animals from North America (the Nearctic region) into South America (the Neotropical region) and vice versa, contributing to today's extraordinary isthmian biodiversity at all levels, from genes to landscapes (Rich and Rich 1983, Stehli and Webb 1985, Webb 2006). Recently, some authors concluded that the Central American closure took place some ten million years earlier (Montes et al. 2015). As a result land mammal faunas from North and South America mingled on a continental scale, including North American ungulates that found their way to South America (tapirs, deer, horses, pumas, canids, bears, and a number of rodents), while glyptodonts — more heavily armored relatives of modern armadillos — and giant anteaters (Myrmecophaga spp.), among others, migrated along the inverse route, from South to North America (Rich and Rich 1983, Webb 2006). Some families of northern land mammals diversified at moderate rates (Procyonidae, Felidae, Tayassuidae, and Camelidae), while others such as Canidae, Mustelidae, Cervidae, and especially Muridae, evolved explosively (Webb 2006). Today this hemispherical process of species migration is known as the Great American Biotic Interchange (GABI), which in fact was first observed by the nineteenth-century English naturalist Alfred Russell Wallace (1876).

At the same time, the Pliocene closure of the isthmus separated the Pacific and Atlantic Oceans that had been connected since the Mesozoic by an interoceanic seaway through the Central American volcanic island arc. As a result, two marine floras and faunas became disconnected, allowing evolution to take place among the now-separated Atlantic and Pacific species populations (Cronin and Dowsett 1996). On top of that, the occurrence of past glaciations on the highest mountains (Kappelle and Horn, chapter 15 of this volume), differences in seasonal patterns of rainfall superimposed on discontinuous mountain chains, temperature gradients changing over short altitudinal ranges (Herrera, chapter 2 of this volume), and the development of rich mineral soils on rugged terrain and lowland plains (Alvarado and Mata, chapter 4 of this volume), led to even higher levels of biotic diversity and ecosystem complexity (Burger 1980, Stehli and Webb 1985, Gómez 1986, Kappelle et al. 1992, Alvarado and Cárdenes, chapter 3 of this volume).

Costa Rican Biodiversity at the Species Level

Over the past three decades, biodiversity inventories in Costa Rica and the world have increased and improved considerably, allowing us to make relatively good estimates of current species diversity (Groombridge 1992, Obando 2002). A recent review of Costa Rican species data shows that out of about 2 million species that have been discovered on Earth, around 95,000 are found in Costa Rica (Obando 2011). That is about 5% of all species officially known to exist on our planet.

Similarly, it is expected that around half a million species thrive in Costa Rica, including all the species unknown until date. That is about 3.6% of the 14 million species that have been estimated to live on Earth (Obando 2002, 2011). Thus, it is believed that so far only 19% of all species living in Costa Rica have been formally discovered and scientifically described. This small percentage underlines the need to continue to invest in species inventories and — in the case of species new to science — prepare and publish formal species descriptions. However, the lack of trained taxonomists and curators needed to conduct the correct identification of biological specimens — a problem known as the Taxonomic Impediment and first observed by the International Union of Biological Sciences (IUBS) and its DIVERSITAS Programme — withholds the country from quickly raising the number of formally known native species, while limiting its ability to conserve, use, and share the benefits of its biological diversity in a socially just manner.

Today, Costa Rica is home to at least 125 species of viruses, 213 Monera (among others, bacteria), 2,300 fungi (with ca. 700 Ascomycota and 1,300 Basidiomycota), 564 algae (including 205 microalgae), 11,467 plants including some 2,000 tree species, 670 Protozoa, 88 nematodes, 66,000 insects (including 16,000 Lepidoptera or butterflies), 1,550 mollusks, 916 fish (781 marine species and 135 freshwater fish), 189 amphibians, 234 reptiles, 854 birds, and 237 mammals of which 107 are bats and 20 are marine mammals (Herrera and Obando 2009). These data reveal that 75% of the 87,000 species known from Costa Rica actually are insects. It also demonstrates that almost 10% of all bird species in the world are indeed found in Costa Rica.