S. Joseph Wright talks with
ScienceWatch.com and answers a few questions about
this month's Fast Moving Front in the field of
Article: Tropical forests in a changing
Journal: TREND ECOL EVOLUT, 20 (10): 553-560 OCT 2005
Smithsonian Trop Res Inst, Apartado 0843-03092, Balboa,
Smithsonian Trop Res Inst, Balboa, Panama.
Why do you think your paper is highly
The paper is a review that attempts to synthesize the impact of a wide
range of anthropogenic drivers on tropical forests. Interest in this
subject is intense because tropical forests support 60% of all species,
influence regional climates far beyond the tropics, are a key component of
the global carbon cycle, and are in transition as climates change,
atmospheric carbon dioxide concentrations increase, and the human
populations and economies of tropical countries expand. Despite their
obvious global significance, relatively few biologists study tropical
forests, and our papers are often cited accordingly.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
support 60% of all species
and are a key component of
global carbon and climate
cycles. The future of these
forests and their responses
to anthropogenic change has
tremendous social and
It would be wonderful if the article really was a synthesis of knowledge.
There is, however, a profound paucity of data from tropical forests,
particularly the long-term monitoring data required to detect indirect
anthropogenic change. For this reason, it would be more accurate to
describe the paper as an overview of recent evidence for direct
(deforestation, hunting) and indirect (global atmospheric and climate
change) anthropogenic impacts. The paper also questions how the limited
evidence for indirect impacts has been interpreted.
Would you summarize the significance of your paper
in layman’s terms?
Tropical forests are important to everyone because moisture that evaporates
from tropical forests sustains global precipitation, including, in
particular, precipitation over the American Midwest, China, and the Balkans
(See: R. Avissar and D. Werth, "Global hydroclimatological teleconnections
resulting from tropical deforestation," J. Hydrometeor
6:134–45, 2005. Tropical forests are also in transition.)
Just 200 years ago, old-growth tropical forests covered one sixth of the
Earth's surface. Within our children's lifetimes, these old-growth forests
will have been replaced by agriculture and human-disturbed forests
everywhere outside nature reserves. If this transition proceeds unchecked,
global rainfall patterns will be changed and massive numbers of species
will become extinct.
The uncertain future of tropical forests represents the greatest unknown in
global climate projections. We urgently need a mechanism to fund the
preservation of tropical forests in order to ensure our own future.
How did you become involved in this research and
were there any particular problems encountered along the way?
My colleagues, Fernando Cornejo-Valverde, Osvaldo Calderón,
Andrés Hernandéz, and I initiated an intensive study to
monitor the production of leaves, flowers, and fruit in several old-growth
forests in Panama beginning in 1985. We were motivated by basic research
questions. Global climate and atmospheric change were not major issues in
Over the past 23 years, we have identified more than 5,000,000 leaves,
flowers, fruits, and seeds to species and our ongoing study provides one of
the few long-term monitoring datasets from old-growth tropical forest that
can be used to address indirect anthropogenic impacts.
Where do you see your research leading in the
With the help of many colleagues and the Center for Tropical Forest Science, I have been able
to extend the research protocols pioneered in Panama to Puerto Rico,
Ecuador, Malaysia, Taiwan, and China. We believe these studies will
provide unprecedented insight into relationships between climate and
primary production in tropical forests. These insights might then allow
us to refine projections of climate change impacts on primary production
in tropical forests.
Do you foresee any social or political implications
for your research?
Tropical forests support 60% of all species and are a key component of
global carbon and climate cycles. The future of these forests and their
responses to anthropogenic change has tremendous social and political
S. Joseph Wright
Smithsonian Tropical Research Institute
Keywords: tropical forests, old-growth tropical
forests, replaced by agriculture, human-disturbed forests, deforestation,
hunting, tropical countries, anthropogenic drivers, regional climates,
global carbon cycle, global atmospheric, climate change, atmospheric carbon
dioxide concentrations increase, global rainfall patterns, numbers of
species will become extinct, indirect anthropogenic impacts.