La Selva Biological Station

Land Acquisition History of La Selva Biological Station, Costa Rica

Leslie Holdridge established La Selva in 1953. Holdridge was an American botanist and climatologist who is known for his widely used classification system of land areas called The Holdridge Life Zones System. He originally purchased the land to use as a farm for experimenting with mixed agriculture, and was especially interested in experimenting with tree crops that could be planted without total clearing of the native forest.[5] In the beginning, La Selva was a challenge to get to; the trip required a long, treacherous dirt road followed by a 4-kilometer dugout canoe trip. In 1968 the Organization of Tropical Studies (OTS) bought the area for fifty thousand US dollars to be used as a private reserve and biological station.[5] OTS was a small, 5-year-old organization created with the goal of facilitating research and education in the tropics. Holdridge encouraged OTS to use La Selva as a research site even before it became OTS property.[5] Holdridge supported research at La Selva until his death in 1999. Since the station's beginnings in 1953, there have been immense changes: access is easy, buildings have been constructed, and the preserve has tripled in size.[5] It is now one of the most important sites for tropical research in the world. In the past few decades, however, the human population around the Station have increased rapidly due to several factors, including the expansion of banana production and government settlement projects.

La Selva Biological Station is located in the Central Conservation Area (91,000 ha) in the north-eastern lowlands of Costa Rica (10°26´ N, 83°59´ W).[3] It encompasses 1,536 ha of classic-lowland tropical rain forest. The Sarapiquí and Puerto Viejo Rivers border the Station to the north, the Peje River to the west, and the Sábalo-Esquina creeks to the east.[3] Braulio Carrillo National Park (47,000 ha) is adjacent to the southern border of the Station and is connected via a 4–6 km wide protected corridor. The closest communities to the Station are La Flamínea (at its north-eastern border) and El Tigre (7 km south-east). Each of these communities has approximately 500 residents and they were established as recently as 1985.[3] Puerto Viejo, the capital of the Cantón Sarapiquí in the province of Heredia, is the nearest major town, with approximately 1,163 residents, and is located seven kilometers north-east of La Selva.[3] La Selva Biological Station is only 2 hours by car from San José airport.

Of the total La Selva property (1,536 ha), 55% is characterized as species-rich, multilayered communities of primary forest.[5] These forests contain impressive trees, lianas, epiphytes, palms, and many other broad-leaved monocots.[2] The remaining areas of the reserve consist of abandoned pastures and plantations in various stages of succession, selectively logged secondary forest, or plots designated for experimental use. The reserve is located at the physiographic transition from the low, steep foothills of the Central Volcanic Cordillera to the vast Caribbean coastal plain in northeastern Costa Rica.[2] At the northern end of the property the elevation is about 35 meters above sea level, but it quickly gives way to steep hills that reach up to 137 meters elevation at the southwest corner.[5] The altitudinal transect connecting La Selva Biological Station to the main body of Braulio Carrillo National Park (approximately 55 km) extends from La Selva to Barva Volcano and includes tropical wet, premontane rain, lower montane rain, and montane rain forest ecosystems.[2] Located at the confluence of the Puerto Viejo and Sarapiquí Rivers, which meet at the station's northern border, the preserve is surrounded on three sides by the natural barriers created by these rivers and their tributaries.[5] The soils along the rivers are composed of Holocene and Pleistocene alluvia and consist primarily of inceptisols with occasional entisols.[2] La Selva's uplands, on the other hand, begin several hundred meters inland from the two rivers and are composed primarily of utisols.

Temperature variation is slight year round, and daily temperatures can fluctuate from 19 to 31 °C (66 to 88 °F). As the climate is tropical wet, rain is common throughout the year, and the average annual rainfall is 4 meters (13 feet).[6] The rainiest months are July, November, and December, while the least rainy season is from February to April.[2] The dry season is rarely long or severe.[5]

Tayassu tajacu in La Selva

Perched Cyanerpes lucidus

Paraponera clavata in La Selva

La Selva's biological resources are rich and largely intact which generates high biological diversity and productivity. The reserve is home to a wide range of wildlife, including large predators, rare birds, and an astonishing number of invertebrates. It is estimated that La Selva contains over 500,000 species, with more than half (about 300,000) consisting of insect species.[7]

A photograph of one of the classrooms at La Selva being used for an Ant Course taught by Dr. Brian Fisher. Dr. Fisher is a renowned entomologist with a passion for ants. He specializes in the large-scale discovery, description and naming of ants. (https://web.archive.org/web/20101114085729/http://www.calacademy.org/science/heroes/bfisher/)

There is a great amount of research conducted at La Selva Biological Station. Each year, more than 240 papers are published from studies performed there. The station has grown and expanded its facilities to include two laboratories, workspaces, an academic center, a workers’ lounge, a researchers’ lounge, a river station, an herbarium, and of course, the surrounding reserve all for research purposes. Researchers can live on site at the station for anywhere between a few days to several months. To accommodate researchers there are cabin dormitories, family housing, a laundry room, a dining hall, and even a gift shop. Most of the tropical ecology research done by scientists at La Selva is related to one of these topics: interactions among interdependent species, carbon sequestration in forests, effects of climate change on ecosystems, mechanisms of speciation, food web dynamics, and maintenance of biodiversity [12] Since there are many endangered species in tropical areas, a great amount of research is conducted on these species. Many researchers write papers analyzing data illustrating species’ decline, and often include thoughts on the conservation efforts needed to preserve them. And because humans are a major factor causing the endangerment of many of these species, mostly through habitat loss from human practices, there is extensive research done on impacts of humans in tropical forests. Research is done both on the effects of large companies conducting oil and mineral exploration, creating plantations, or cattle farming and also on local peoples who live in the forest and use its resources.

Examples of research projects conducted at La Selva:

• Army ants and their guests
• Comparison of eye size of bats
• Current and future carbon budgets for tropical rainforests
• Deforestation rates
• Root productivity in soil gradients

Due to La Selva's large area and the fact that many people are permanent residents living within the reserve, potential threats to the station and the surrounding area do exist. Wild habitats and habitat connectivity in the region are seriously threatened by deforestation and wetland loss. Solutions to habitat fragmentation and loss have been proposed by the Executive Committee that oversees the San Juan-La Selva Biological Corridor. A biological corridor would effectively bridge habitat gaps and allow species to migrate as normal [13] Another potential threat to the reserve is illegal hunting within the reserve's land. Results of an oral questionnaire given to local residents of the reserve showed that 4% admitted to hunting within the year prior to the survey while 86% denied any hunting activity. 8% of respondents did not know if anyone in their household had hunted and 2% expressed no opinion. Species reported by the respondents to have been hunted included iguana (Iguana iguana), deer (Mazama americana, Odocoileus virginianus), tinamou (Tinamidae), bobo fish (Joturus pichardi) and paca (Agouti paca). Bobo fish, paca, and tinamou were the most popular hunted species.[3]

Additionally, there have been many changes in abundance and species composition within La Selva Biological Station over the past few decades. For example, there have been significant changes to the list of bird species found within the reserve. Since 1960, most of the forest surrounding the Station has been converted to agricultural uses.[10] Although, further research is needed, evidence suggests that insectivorous birds have a significant impact on levels of herbivory, and the loss of a significant fraction of an entire guild, specifically forest understory insectivores, and then top down trophic cascades could alter arthropod and plant communities and ultimately biodiversity.[10]

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  Access within La Selva Biological Station
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  Boundaries of La Selva
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  Buildings in La Selva Biological Station
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  Digital Elevation Model(DEM) of La Selva Biological Station
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  Geology in La Selva Biological Station, Costa Rica
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  Rivers in La Selva
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  Watersheds in La Selva
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  The main path through La Selva
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  The bridge over the Puerto Viejo River in La Selva
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  Bridge in La Selva
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  A Walking Palm at La Selva
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  The habitat
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  The jungle
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  Bothriechis schlegelii
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  Cebus capucinus
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  Phrictus quinqueparitus
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  Nephila clavipes
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  Iguana iguana
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  Deimerandra emarginata
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  Agalychnis callidryas
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  Agallychnis callidryas tadpoles
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  Porthidium nasutum
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  Choloepus hoffmanni
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  Orange-horn Katydid (Copiphora sp)

• UGA Costa Rica

Wikimedia Commons has media related to Estación Biológica La Selva.

• La Selva Biological Station species list
• La Selva Protected Zone at Costa Rica National Parks
• OTS page for La Selva
• La Selva Digital Flora