

[
] 82
Smithsonian Institution
Global Earth Observatories
Ira Rubinoff, Smithsonian Institution, Office of the Undersecretary for Science;
Eldredge Bermingham and Charles Lydeard, Smithsonian Tropical Research Institute;
Stuart J. Davies, Smithsonian Tropical Research Institute and Arnold Arboretum, Harvard University
T
he Smithsonian Tropical Research Institute (STRI) is a
US organization dedicated to advancing fundamental
scientific discovery and understanding of biological diver-
sity in the tropics and its contribution to human welfare. STRI
plays a critical role for the US Government and the Smithsonian
by maintaining world-class research facilities in Panama. Last
year more than 1,000 resident and visiting scientists accessed
diverse tropical environments, including rain forest and coral
reef ecosystems at the facility. STRI serves as official custodian
for the Barro Colorado Nature Monument (BCNM) in Panama
under the terms of the Convention on Nature Protection and
Wildlife Preservation in the Western Hemisphere, which was
ratified by the US Senate in April 1941. The BCNM is the only
mainland tropical reserve under US stewardship.
More than 25 years ago STRI established a large-scale forest
research plot on 50 hectares (approximately 120 acres) of lowland
tropical forest on Barro Colorado Island (BCI), a fully protected
tropical forest within the BCNM. Within the plot, every free-stand-
ing tree with a diameter at breast height of at least one centimetre
was tagged, measured, mapped and identified to species. Beginning
in 1980 the plot has been censused every five years, with the sixth
census completed in 2006.
Over the years, re-censuses have revealed that tropical forest
populations are incredibly dynamic and responsive to climate
change. For example, in only one census interval of five years, more
than 40 per cent of the tree species in the plot changed by more
than ten per cent in total abundance. This was apparently in
response to a severe El Niño drought that elevated death rates up
to 20 times those of non-drought years. The large-scale and stan-
dard forest census methods developed on BCI proved to be a
powerful approach to studying the dynamics of tropical forests. By
1990, scientists around the world had replicated the STRI methods,
and a global network of research plots emerged.
The network was initially named the Center for Tropical Forest
Science (CTFS), and although administered by STRI, individual
forest plots are led and managed in each country by one or more
partner institutions (see Appendix). For example, the Indian
Institute of Science manages the forest dynamics plot in Mudumalai,
India, and the National Institute of Research of the Amazônia is the
custodian of the CTFS plot in the Central Amazon. In addition,
CTFS in Asia is coordinated through a partnership with
the Arnold Arboretum of Harvard University.
CTFS coordinates research activities using standard-
ized methods on forest plots ranging from 2 – 52 hectares
that now include 20 sites in 15 tropical countries in Latin
America, Africa and Asia. The CTFS plots involve
hundreds of scientists from more than two dozen insti-
tutions. Over the past 25 years, the CTFS network has
created the first actuarial table for tropical trees around
the world, thus providing a basis for determining quan-
titatively how trees and forest ecosystems are responding
to the Earth’s changing climate. This international collab-
oration is now monitoring the growth and survival of 3.5
million trees in over 6,500 species, which constitutes over
12 per cent of all known tropical tree species. The CTFS
system has now matured to the point where there is a
tremendous and unique opportunity to expand the
programme into a truly interdisciplinary research endeav-
our that will enable the world’s scientists to investigate
key indicators of global environmental health.
STRI is now in the process of transforming its
network of tropical forest plots into the Smithsonian
Institution Global Earth Observatories (SIGEO).
Although tremendous advances in our understanding
of tropical diversity and dynamics have been gained
from 25 years of research across the network of tropi-
cal forest plots, CTFS and its system of global earth
observatories is poised to make an even larger contri-
bution through monitoring the effects of anthropogenic
increases in atmospheric CO
2
, nitrogen and general air
pollution at local, regional and global scales.
The global earth observatories will provide baseline
data to help solve real-world problems through real-
time dissemination of critical data and cutting-edge
science. It is worth noting that the network is
extremely well utilized by independent university-
associated faculty and network partners, thus SIGEO
leverages huge intellectual horsepower. Over 200
scientists have published over 1,000 scientific articles
from the CTFS data sets, attesting to the broad usabil-
ity and benefits of the network.
GEOSS C
OMPONENTS
– O
BSERVING
S
YSTEMS