The Rise of Brazil as an Agricultural Superpower and the Dilemma over the Amazon Rain Forest: A Treadmill of Production View

2009 ◽  
Author(s):  
Luiz C. Barbosa
Keyword(s):  
Rain Forest ◽  
Amazon Rain Forest ◽  
Treadmill Of Production

Satellite Based Study on Amazon Rain Forest Fires and Effect on Climate

2019 ◽  
Author(s):  
Madhura Chakraborty ◽  
Goutam Dey ◽  
Rohit Kumar Prasad Gupta
Keyword(s):  
Forest Fires ◽  
Rain Forest ◽  
Amazon Rain Forest

A New Species of Proceratophrys (Anura: Leptodactylidae) from the Amazon Rain Forest

2000 ◽  
Vol 34 (2) ◽  
pp. 173 ◽  
Author(s):  
Ariovaldo A. Giaretta ◽  
Paulo S. Bernarde ◽  
Marcelo N. de C. Kokubum
Keyword(s):  
New Species ◽  
Rain Forest ◽  
Amazon Rain Forest ◽  
A New Species

scholarly journals Coupled carbon-water exchange of the Amazon rain forest, I. Model description, parameterization and sensitivity analysis

2005 ◽  
Vol 2 (2) ◽  
pp. 333-397 ◽  
Author(s):  
E. Simon ◽  
F. X. Meixner ◽  
L. Ganzeveld ◽  
J. Kesselmeier
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area ◽  
Rain Forest ◽  
Canopy Structure ◽  
Leaf Nitrogen ◽  
Optical Parameters ◽  
Amazon Rain Forest ◽  
Leaf Level ◽  
Net Assimilation ◽  
Parameter Values

Abstract. Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the terrestrial vegetation and the lower atmosphere. Within the present study, a modified CANVEG scheme is described. A generic parameterization and characterization of biophysical properties of Amazon rain forest canopies is inferred using available field measurements of canopy structure, in-canopy profiles of horizontal wind speed and radiation, canopy albedo, soil heat flux and soil respiration, photosynthetic capacity and leaf nitrogen as well as leaf level enclosure measurements made on sunlit and shaded branches of several Amazonian tree species during the wet and dry season. The sensitivity of calculated canopy energy and CO2 fluxes to the uncertainty of individual parameter values is assessed. In the companion paper, the predicted seasonal exchange of energy, CO2, ozone and isoprene is compared to observations. A bi-modal distribution of leaf area density with a total leaf area index of 6 is inferred from several observations in Amazonia. Predicted light attenuation within the canopy agrees reasonably well with observations made at different field sites. A comparison of predicted and observed canopy albedo shows a high model sensitivity to the leaf optical parameters for near-infrared short-wave radiation (NIR). The predictions agree much better with observations when the leaf reflectance and transmission coefficients for NIR are reduced by 25–40%. Available vertical distributions of photosynthetic capacity and leaf nitrogen concentration suggest a low but significant light acclimation of the rain forest canopy that scales nearly linearly with accumulated leaf area. Evaluation of the biochemical leaf model, using the enclosure measurements, showed that recommended parameter values describing the photosynthetic light response, have to be optimized. Otherwise, predicted net assimilation is overestimated by 30–50%. Two stomatal models have been tested, which apply a well established semi-empirical relationship between stomatal conductance and net assimilation. Both models differ in the way they describe the influence of humidity on stomatal response. However, they show a very similar performance within the range of observed environmental conditions. The agreement between predicted and observed stomatal conductance rates is reasonable. In general, the leaf level data suggests seasonal physiological changes, which can be reproduced reasonably well by assuming increased stomatal conductance rates during the wet season, and decreased assimilation rates during the dry season. The sensitivity of the predicted canopy fluxes of energy and CO2 to the parameterization of canopy structure, the leaf optical parameters, and the scaling of photosynthetic parameters is relatively low (1–12%), with respect to parameter uncertainty. In contrast, modifying leaf model parameters within their uncertainty range results in much larger changes of the predicted canopy net fluxes (5–35%).

scholarly journals The role of termite CH<sub>4</sub> emissions on ecosystem scale: a case study in the Amazon rain forest

2020 ◽  
Author(s):  
Hella van Asperen ◽  
João Rafael Alves-Oliveira ◽  
Thorsten Warneke ◽  
Bruce Forsberg ◽  
Alessandro Carioca de Araujo ◽  
...  
Keyword(s):  
Rain Forest ◽  
Emission Factor ◽  
Field Studies ◽  
Ch4 Emission ◽  
Termite Mound ◽  
Flux Chamber ◽  
Termite Mounds ◽  
Ch4 Emissions ◽  
Amazon Rain Forest

Abstract. The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in-situ CH4 emission measurements of termite mounds and termite mound sub samples, performed in the Amazon rain forest. Emissions of five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser, measuring CH4 and CO2. In addition, the emission of mound sub samples was measured, after which termites were counted, so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0–34.8 nmol mound−1 s−1 for CH4 and between 1.6–13.5 μmol mound−1 s−1 for CO2. A termite emission factor of 0.32 μmol CH4 gtermite−1 h−1 was found, which is twice as high as the only other reported average value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 50–120 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystems CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local termite mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1 on average emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite density numbers, resulting in an estimate of termite emitted CH4 of ~1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this Terra Firme ecosystem.

Estimation of mortality and survival of individual trees after harvesting wood using artificial neural networks in the amazon rain forest

2018 ◽  
Vol 112 ◽  
pp. 140-147 ◽  
Author(s):  
Leonardo Pequeno Reis ◽  
Agostinho Lopes de Souza ◽  
Pamella Carolline Marques dos Reis ◽  
Lucas Mazzei ◽  
Carlos Pedro Boechat Soares ◽  
...  
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Rain Forest ◽  
Amazon Rain Forest ◽  
Artificial Neural ◽  
Individual Trees

scholarly journals Coupled carbon-water exchange of the Amazon rain forest, I. Model description, parameterization and sensitivity analysis

2005 ◽  
Vol 2 (3) ◽  
pp. 231-253 ◽  
Author(s):  
E. Simon ◽  
F. X. Meixner ◽  
L. Ganzeveld ◽  
J. Kesselmeier
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area ◽  
Rain Forest ◽  
Canopy Structure ◽  
Leaf Nitrogen ◽  
Optical Parameters ◽  
Amazon Rain Forest ◽  
Leaf Level ◽  
Net Assimilation ◽  
Parameter Values

Abstract. Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the terrestrial vegetation and the lower atmosphere. Within the present study, a modified CANVEG scheme is described. A generic parameterization and characterization of biophysical properties of Amazon rain forest canopies is inferred using available field measurements of canopy structure, in-canopy profiles of horizontal wind speed and radiation, canopy albedo, soil heat flux and soil respiration, photosynthetic capacity and leaf nitrogen as well as leaf level enclosure measurements made on sunlit and shaded branches of several Amazonian tree species during the wet and dry season. The sensitivity of calculated canopy energy and CO2 fluxes to the uncertainty of individual parameter values is assessed. In the companion paper, the predicted seasonal exchange of energy, CO2, ozone and isoprene is compared to observations. A bi-modal distribution of leaf area density with a total leaf area index of 6 is inferred from several observations in Amazonia. Predicted light attenuation within the canopy agrees reasonably well with observations made at different field sites. A comparison of predicted and observed canopy albedo shows a high model sensitivity to the leaf optical parameters for near-infrared short-wave radiation (NIR). The predictions agree much better with observations when the leaf reflectance and transmission coefficients for NIR are reduced by 25–40%. Available vertical distributions of photosynthetic capacity and leaf nitrogen concentration suggest a low but significant light acclimation of the rain forest canopy that scales nearly linearly with accumulated leaf area. Evaluation of the biochemical leaf model, using the enclosure measurements, showed that recommended parameter values describing the photosynthetic light response, have to be optimized. Otherwise, predicted net assimilation is overestimated by 30–50%. Two stomatal models have been tested, which apply a well established semi-empirical relationship between stomatal conductance and net assimilation. Both models differ in the way they describe the influence of humidity on stomatal response. However, they show a very similar performance within the range of observed environmental conditions. The agreement between predicted and observed stomatal conductance rates is reasonable. In general, the leaf level data suggests seasonal physiological changes, which can be reproduced reasonably well by assuming increased stomatal conductance rates during the wet season, and decreased assimilation rates during the dry season. The sensitivity of the predicted canopy fluxes of energy and CO2 to the parameterization of canopy structure, the leaf optical parameters, and the scaling of photosynthetic parameters is relatively low (1–12%), with respect to parameter uncertainty. In contrast, modifying leaf model parameters within their uncertainty range results in much larger changes of the predicted canopy net fluxes (5–35%).

Sign in / Sign up

Export Citation Format

Share Document