Related Experiment Video
Updated: Jul 11, 2026
10:16
Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling
Published on: January 16, 2014
Tropical forests and the global carbon cycle
Science (New York, N.Y.)
|January 1, 1988
Summary
Tropical forest clearing released less carbon than previously estimated in 1980. New modeling, incorporating ecosystem recovery, suggests a smaller net carbon dioxide flux from these vital ecosystems.
Area of Science:
- Environmental Science
- Ecology
- Climate Science
Background:
- Tropical forests play a critical role in global carbon cycling.
- Accurate estimation of carbon release from land-use change is essential for understanding atmospheric CO2 levels.
- Previous estimates of carbon flux from tropical deforestation varied significantly.
Purpose of the Study:
- To quantify the net carbon dioxide flux from tropical ecosystems to the atmosphere in 1980.
- To assess the impact of land-use change, specifically forest clearing, on vegetation and soil carbon.
- To evaluate the sensitivity of carbon flux estimates to data uncertainties.
Main Methods:
- Utilized a computer model simulating land-use change impacts on vegetation and soil carbon.
- Incorporated new data on key determinants of carbon release from tropical forest clearing.
- Included ecosystem recovery processes in the modeling.
Main Results:
- The tropics were a net source of 0.4 to 1.6 x 10^15 grams of carbon in 1980.
- Decreases in soil organic matter contributed 0.1 to 0.3 x 10^15 grams.
- Burning and decay of cleared vegetation accounted for 0.3 to 1.3 x 10^15 grams of carbon release.
Conclusions:
- New estimates of biotic carbon release from the tropics are lower than many previous figures.
- The revised estimates suggest a potentially more balanced global carbon budget.
- Reduced biomass estimates, lower clearing rates, and inclusion of ecosystem recovery contributed to the lower flux values.
Related Concept Videos
01:14The Carbon Cycle
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
01:24Microbes and the Carbon Cycle
The carbon cycle is a fundamental Earth process involving the transfer of carbon among the biosphere, lithosphere, atmosphere, and hydrosphere. It plays a critical role in regulating the planet’s climate and supporting life by cycling carbon through various chemical forms and reservoirs. Carbon primarily circulates as carbon dioxide (CO₂), representing its oxidized form, while reduced forms such as methane (CH₄) and organic compounds also play essential roles.Microbial activity is central to...
01:27Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
00:54What are Biogeochemical Cycles?
The most common elements in organic molecules, carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, are only available in the ecosystem in limited amounts. Therefore, these nutrients must be recycled through both biotic and abiotic components of the ecosystem, in processes generally called biogeochemical cycles.
01:28Carbon-dioxide Fixation
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...