Barro Colorado Island is located in the man-made Gatun Lake

Gatun Lake

Gatun Lake is a large artificial lake situated in the Republic of Panama; it forms a major part of the Panama Canal, carrying ships for of their transit across the Isthmus of Panama....

 in the middle of the Panama Canal

Panama Canal

The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

. The island

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

 was formed when the waters of the Chagres River

Chagres River

The Chagres River is a river in central Panama. The central part of the river is dammed by the Gatun Dam and forms Gatun Lake, an artificial lake that constitutes part of the Panama Canal. Upstream lies the Madden Dam, creating the Alajuala Lake that is also part of the Canal water system...

 were dammed to form the lake. When the waters rose, they covered a significant part of the existing rainforest

Rainforest

Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...

, and the hilltops remained as islands in the middle of the lake. It has an area of 15.6 km² (6 sq mi).

The island was set aside as a nature reserve on April 17, 1923 by the U.S. Government. Initially administered by the Panama Canal Company under the direction of James Zetek, since 1946 Barro Colorado Island has been administered by the Smithsonian

Smithsonian Institution

The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...

, together with five adjacent peninsulas, as the Barro Colorado Nature Monument (BCNM). The BCNM has an area of 54 km². It is among the most-studied areas of tropical forest in the world. The Smithsonian Tropical Research Institute

Smithsonian Tropical Research Institute

The Smithsonian Tropical Research Institute in Panama, the only bureau of the Smithsonian Institution based outside of the United States, is dedicated to understanding biological diversity. What began in 1923 as small field station on Barro Colorado Island in the Panama Canal Zone has developed...

 (STRI) has a permanent research center on the island, dedicated to studying rainforest

Rainforest

Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...

 ecosystems. Because the Island's diverse ecosystem has been very little altered by humans, Barro Colorado has been studied for over eighty years within a great variety of biological disciplines. Only the larger fauna disappeared from Barro Colorado after the lake was flooded in 1914. Many scientific studies have been conducted to document the changes in the species composition of the island.

Hundreds of scientists conduct research projects on Barro Colorado Island every year.

In 1978, Thomas Croat published his Flora of Barro Colorado Island documenting the plant species on the island. In 1999, Egbert Leigh, who first visited the island in 1966, and now spends half his week there, published Tropical Forest Ecology : A View from Barro Colorado Island. In 2002 The Tapir's Morning Bath by Elizabeth Royte

Elizabeth Royte

Elizabeth Royte is an American science/nature writer. She is best known for her books Garbage Land , The Tapir's Morning Bath: Solving the Mysteries of the Tropical Rain Forest , and Bottlemania: How Water Went on Sale and Why We Bought It Elizabeth Royte is an American science/nature writer. She...

 was published, chronicling the lives and work of scientists working on the island.

Forest dynamics plot

In 1980, a 50-ha forest dynamics

Forest dynamics

Forest dynamics describes the underlying physical and biological forces that shape and change a forest. That is, the continuous state of change that alters the composition and structure of a forest....

 plot was established on BCI by researchers from STRI and Princeton University

Princeton University

Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....

. The first census was conducted in 1982 and recorded every free-standing tree and shrub in the plot of more than 1-cm dbh

Diameter at breast height

Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....

, totalling approximately 240,000 stems of 303 different species. It has been recensused every 5 years since 1985, allowing scientists to study the normal dynamics of the forest, as well as extreme events, such as El Niño. Another 50 ha plot was later established in the Pasoh forest reserve

Pasoh Forest Reserve

The Pasoh Forest Reserve, a nature reserve located about 8 km from Simpang Pertang, Malaysia and around 70 km southeast of Kuala Lumpur, has a total area of 2450 hectares, with a core area of 600ha surrounded by a buffer zone. Palm oil plantations surround on three sides of the reserve...

, Malaysia in 1987, allowing the dynamics of two tropical forests to be compared.