PROGRAM TITLE:	Tropical Forest Science Program
ACTIVITY STREAM:	Process Studies (also relevant to Observation and 
Data Management)
SCIENCE ELEMENT:	Ecological Systems and Dynamics

 SMITHSONIAN INSTITUTION
SMITHSONIAN TROPICAL RESEARCH INSTITUTE

SCIENTIFIC MERIT:  Tropical forests are an important reservoir for carbon, a 
mediator of the global hydrologic cycle, and repository for a large percentage  
of the world's biological diversity, yet the reciprocal effects of climate on 
tropical forest dynamics, and of tropical forests on global climate, are very 
poorly understood.  The objective of the Smithsonian's Tropical Forest 
Science Program (TROFOS) is a comprehensive understanding of the 
structure and dynamics of tropical forests, especially in relation to climate 
variables, through an integrated program including both observational and 
process-oriented research.  Important components of this program include (1) 
long-term monitoring of physical environmental factors, including 
temperature, rainfall, humidity, and solar radiation;  (2) the documentation 
and long-term monitoring of the biological diversity, structure, growth, and 
regeneration of tropical forests;  (3) studies of the physiology of CO2 exchange 
by tropical forest plants, especially in the canopy, where most photosynthesis 
and carbon fixation takes place;  (4) synthesis of information and testing of 
hypotheses concerning the physical and biotic factors influencing forest 
structure and regeneration;  and (5) providing information on potential 
feedbacks between global environmental change and tropical forest processes.

Major operational components of TROFOS are:  (1) The Tropical Forest 
Dynamics Program, in which all trees greater than one centimeter in 
diameter in a 50-hectare plot are mapped, measured and identified.  Plots are 
recensused at intervals of five years to examine growth rates, survivorship, 
and regeneration in relation to short and long-term climatic variations.  (2) 
The Long-term Environmental Monitoring Program, which now has 20 years 
of baseline data on the interrelationship of physical and biological 
environmental variables in Central Panama.  (3) The Tropical Plant 
Physiology Program examines plant gas exchange in relation to 
environmental factors, and includes experimental studies of the effects of 
elevated levels of atmospheric CO2.  STRI is seeking to strengthen TROFOS 
by improving data management, analysis, and information distribution 
systems, especially for the Tropical Forest Dynamics Programs.

TROFOS builds on a 68-year history of scientific research and a 20-year 
baseline of long-term environmental monitoring at STRI's Barro Colorado 
site in Panama.  The first Forest Dynamics Plot was set up in 1980 in Panama, 
and has been recensused twice.  Two plots were set up in the mid-1980's in 
Asia and have been recensused once.

STAKEHOLDERS:  TROFOS activities are closely related to the objectives of 
the established Global Change and Terrestrial Ecosystems (GCTE) project of 
the IGBP, and relevant as well to the potential Global Change and Ecological 
Complexity (GCEC) project.  Monitoring of greenhouse gases has been done in 
collaboration with DOI/U.S.G.S., and plant physiology in collaboration with 
USDA/U.S.F.S.  The Tropical Forest Dynamics Program is a collaboration 
with Harvard and Princeton Universities, the Forest Research Institute of 
Malaysia, and the Indian Institute of Science.  Within the Smithsonian, 
TROFOS is linked to the Smithsonian Environmental Research Center 
(Canopy Access and Plant Physiology Programs) and the National Air and 
Space Museum (ground truth of remote sensing data).

POLICY RELEVANCE:  The program is strongly focused on high-priority 
objectives under the Integrating Theme of Ecological Systems and Population 
Growth and Decline:  Interannual correlations established between ecosystem 
processes and climatic variables, Correlations established between current 
species and ecosystem distribution and interannual climatic variability, 
Influence of disturbance and dominant species identified;  under Predicting 
threshold responses:  Concept of threshold response quantified.  Also under 
Greenhouse Gases, Terrestrial sources/sinks:  Carbon content and CO2 fluxes 
quantified;  Plant physiological mechanisms controlling CO2 fixation defined;  
Interannual correlations established between trace gas fluxes and climatic 
variables. 

PROGRAM CONTACTS:

SI SGCR Representative:	Ted A. Maxwell
		NASM MRC 315
		Smithsonian Institution
		Washington, D.C.  20560
		202 357 1424
		FAX:  202 786 2566
		Email: tmaxwell@ceps.nasm.edu
	
Bureau Representative:	Anthony Coates
		Smithsonian Tropical Research Institute
		APO AA 34002-0948
		507 27 6022
		FAX: 507 32 6197