Smithsonian Institution Global Earth Observatories
Lilly Dickey Woods, Nashville, IN, USA Wytham Woods, UK Haliburton Forest, Canada Harvard Forest, MA, USA Smithsonian Environmental Research Center, MD, USA Smithsonian Conservation Biology Institute, VA, USA Wabikon Lake Forest, WI, USA Wind River, WA, USA Yosemite National Park, CA, USA Santa Cruz, CA, USA Oceania Panama La Planada, Colombia Yasuni, Ecuador Manaus, Brazil Luquillo, Puerto Rico Korup, Cameroon Rabi, Gabon Ituri, Democratic Republic of Congo Mpala, Kenya Ilha do Cardoso, Brazil Bukit Timah, Singapore Pasoh, Malaysia Sinharaja, Sri Lanka Mudumalai, India Khao Chong, Thailand Huai Kha Khaeng, Thailand Doi Inthanon, Thailand Mo Singto, Thailand Xishuangbanna, China Nonggang, China Dinghushan, China Donlingshan, China Changbaishan, China Tiantongshan, China Gutianshan, China Fushan, Taiwan Tiantongshan, China Nanjenshan, Taiwan Hong Kong, China Kuala Belalong, Brunei Darussalam Palanan, Philippines Danum Valley, Malaysia Lambir, Malaysia Wanang, Papua New Guinea


Barro Colorado Island's
50-hectare plot
Forest biologists from 21 countries and 75 partner institutions share the same passion to understand forest dynamics. Taking the pulse of forests at 47 long-term monitoring sites, they map, mark and measure more than 4.5 million trees from 8,500 species.

The resulting knowledge base, accumulated over 30 years, reveals the origins of biological diversity, elucidates the role of forests in the global carbon cycle and provides policy makers with new knowledge about the implications of environmental change. Scientific information from the network contributes to innovative, profitable strategies for land use, reforestation and restoration of some of the most biologically diverse places on the planet.

This research platform, coordinated by the Smithsonian Tropical Research Institute, has recently inspired a proposal for a similar system of ocean habitat comparisons. As one of the premier U.S.-led international partnerships for ecological research, this long-term and large-scale approach has led to unique endeavors that promise to enhance society’s ability to evaluate and respond to environmental change.

The first questions
Why are there more than 2,000 tree species in tiny Panama, and only 1,000 species in all of North America? Why are the vast majority of tropical tree species so rare?

In 1980 ecologists Robin Foster and Stephen Hubbell created a 50-hectare (110 acre) plot at the Smithsonian’s research station on Barro Colorado Island in Panama with the intention of obtaining a representative sample of all of the species in this lowland tropical forest.

They mapped, identified and measured every stem at least 1 centimeter (0.4 inches) in diameter. Their final tally was 299 species and 208,400 trees. Since then, censuses have been conducted every five years (seven times), resulting in a comprehensive set of statistics on birth (recruitment), growth and death of each species.

Their project steadily grew into a global network of plots coordinated by the Smithsonian’s Center for Tropical Forest Science, CTFS. By 1986, an Asian plot at Pasoh in Malaysia had been inaugurated through an association with Peter Ashton at Harvard’s Arnold Arboretum. Further plots were installed at Mudumalai in India In 1987 and in Lambir, Malaysia in 1991. By 1994, a plot in the Ituri Forest of the Democratic Republic of Congo added the African tropics to the network.

Today, there are 23 plots in Asia, nine in Latin America, eight in North America, four in Africa, three in Oceania and one in Europe. To acknowledge the Smithsonian’s role as coordinator, the plot system is known as the Smithsonian Institution Global Earth Observatory System, or SIGEO.

Each plot, typically 25 or 50 hectares, has a common structure. Data is collected according to a standard protocol to make direct comparisons between forests possible and detect patterns that would otherwise be impossible to recognize. Today the scale and intensity of the CTFS research program remain unprecedented in forest science.

Forests and The Environment Forest Dynamics Looking Forward
One of the key roles played by the SIGEO network is to define, quantify and analyze the benefits to human society that... The network provides answers to scientific questions about forests that were impossible to address at isolated sites. Federal and private funding has supported the development of this unique research platform as it has grown from a single...

The Center for Tropical Forest Science and each of its partner institutions depend on the financial and logistical support of their home institutions as well as generous donations from dozens of foundations, government agencies, corporations, and individuals.
Here we acknowledge the generous support of a few organizations that have contributed major support to the operations of the entire CTFS network:

• The Andrew W. Mellon Foundation
• F. H. Levinson Fund
• The John D. and Catherine T. MacArthur Foundation
• National Institute of Environmental Studies (Japan)
• Smithsonian Institution
• U.S. National Science Foundation
• John Swire & Sons Ltd.