Browsing by Autor "Philip M. Fearnside"

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Bolivia’s political transition and COP30
(American Association for the Advancement of Science, 2025) Flora Magdaline Benítez Romero; Philip M. Fearnside
Carbon Content of Amazonian Commercial Tree Boles: Implications for Forest Management
(Multidisciplinary Digital Publishing Institute, 2025) Flora Magdaline Benítez Romero; Laércio Antônio Gonçalves Jacovine; Angélica de Cássia Oliveira Carneiro; Marcelo Vitor Gualberto Santos Chaves; Eronildo Braga Bezerra; Juan Pablo Sandoval Lafuente; Samuel José Silva Soares da Rocha; Maria Teresa Gomes Lopes; Philip M. Fearnside
Reliable values for carbon content in trees are essential for quantifying forest carbon stocks and estimating carbon dioxide emissions. This study analyzed the carbon content in the boles of commercial tree species in the Brazilian state of Acre, in the southwestern Amazon. Composite samples were prepared from wood wedges obtained along each individual’s commercial bole (the trunk from the point of cut to the first significant branch). Fifty-seven trees were analyzed, spanning nine families, seventeen genera, and nineteen species in the Amazon forest. The results revealed a variation in carbon content ranging from 49.08% (±3.36) to 51.81% (±0.6), with an overall mean of 50.48% (±0.42). Handroanthus serratifolius, Astronium lecointei, and Dipteryx odorata exhibited the highest carbon contents. The statistical analysis included the calculation of 95% confidence intervals for each species, indicating the precision of the carbon content estimates. ANOVA analysis showed a large effect (η2 = 0.83), indicating that 83% of carbon variability is due to species differences, highlighting the distinct carbon profiles across species. One species (Ceiba pentandra) showed a significant increase in carbon with height along the bole, while the others showed varying but non-significant trends with height. Mean carbon content differed significantly (Tukey’s post hoc test) among the 19 species studied, with the greatest difference between H. serratifolius and Ceiba pentandra. Although differences between species may seem small, in some cases, they can lead to considerable underestimations or overestimations of carbon stocks and emissions when extrapolated to large areas such as the Amazon. The mean carbon content measured in this study (50.48%) exceeds the 0.47 IPCC default value generally used in national reports to the Climate Convention and in various estimates of deforestation emissions and Amazon carbon stocks. This suggests that both emissions and stocks may have been underestimated.
Diversity and Structure of Climbing Plants in an Urban Forest Fragment
(2024) José Henrique Costa e Penha Júnior; Rosana Barbosa de Castro Lopes; Flora Magdaline Benítez Romero; Guido Hernán Vásquez Colomo; Philip M. Fearnside
Climbers are herbaceous or woody plants that germinate in the soil and remain rooted throughout their lives, needing other plants to support their development. The aim of this study was to analyze the edge effect on the climbing plant community in the forest fragment of the Federal University of Amazonas. Fifty plots were set up for sampling. The species were grouped and phytosociological parameters were calculated. A total of 613 individuals were recorded, represented by 13 families found inside and on the edges of the UFAM forest fragment. The family with the highest ecological importance value (IV) was Fabaceae. The genera Bauhinia and Derris had the highest ecological importance values, both at the edge and in the interior of the forest. The scandent climbing mode was the most important and was observed in 56 species. This study confirmed the diversity of climbing plants. Although there were more climbing plants at the edge of the forest than in the interior due to the greater luminosity, the scandent climbing habit was abundant in both environments. Climbing plants are a part of the native vegetation of the forest fragment with their richness and diversity. Among other roles, climbing plants contribute ecologically by providing food and shelter for living organisms.
EL APROVECHAMIENTO FORESTAL BOLIVIANO: CARACTERIZACIÓN DE LAS NORMATIVAS QUE REGULAN LA GESTIÓN FORESTAL
(2023) Flora Magdaline Benítez Romero; Guido Hernán Vásquez Colomo; Richard Andres Benitez Romero; Marcos Vichenzo Abasto Antezana; Ariz Humeres Alvez; Carlos Maradey Viera; Rosana Barbosa de Castro Lopes; Philip M. Fearnside
Debido a los problemas de degradación, deforestación, e incendios forestales, y la creciente pérdida de biodiversidad en la región amazónica, surge la necesidad de analizar las políticas públicas adecuadas que reconozcan las funciones y actividades deben cumplir para el aprovechamiento de los recursos naturales y sus límites y capacidades de regeneración del bosque. En ese sentido, el presente documento tiene el objetivo de caracterizar las leyes, normas y todos sus anexos que regulan el aprovechamiento de los recursos naturales en la región Amazónica boliviana. Actualmente existen normativas, que rigen desde 1996, Ley Forestal 1700 con su reglamentación, Resolución Ministerial N°248/98, y leyes que ayudan a normar el manejo de los recursos naturales, como Ley INRA 1715, Ley de Medio Ambiente 1333 y Ley Derechos de la Madre Tierra 071. La Ley Forestal 1700 da los lineamientos base de la gestión forestal del Estado boliviano; por consiguientes es fundamental la protección, conservación del medio ambiente y abastecimiento de materia prima al sistema económico y social. Asimismo, la Ley de Reforma Agraria, busca proteger, y rehabilitar cuencas hidrográficas, detener la erosión de la tierra y la degradación de los bosques. Además, la Ley de Medio Ambiente establece que “Las entidades públicas deben fomentar las actividades de investigación (flora y fauna)” e consecuentemente, los informes deben contener sugerencias, de manejo y gestión de los recursos naturales de forma sostenible, para garantizar una producción permanente, como lo explica la ley INRA 1715 y la Ley Madre Tierra 071. Asimismo, los instrumentos de gestión (Plan General de Manejo Forestal, Plan de Gestión Integral de Bosques y Tierra, Plan de Manejo Integral de Bosques y Plan de Ordenamiento Predial POP), operación (Plan Operativo de Aprovechamiento Forestal y Plan Operativo de Gestión Integral) y seguimiento (Informe Anual del Plan Operativo de Aprovechamiento Forestal e Informe Anual del Plan Operativo de Gestión Integral) son fundamentales para el aprovechamiento y conservación de los bosques. En vista de ello, los instrumentos de gestión forestal son normativas que se aplican en la etapa de aprovechamiento de los recursos forestales y su manutención de los bosques a lo largo del tiempo. Sin embargo, existe una brecha sobre la evaluación post aprovechamiento en la Amazonia boliviana, lo que dificulta a tomar acciones y elaboración de políticas públicas relacionadas a la regeneración de especies y monitoramiento de la vegetación en áreas de manejo forestal. Por lo tanto, es necesario la actualización, inclusión y elaboración de instrumentos legales pos aprovechamiento e de técnicas que regulen y mitiguen los efectos del aprovechamiento forestal en la amazonia boliviana.
Testing for criticality in ecosystem dynamics: the case of Amazonian rainforest and savanna fire
(Wiley, 2010) Salvador Pueyo; Paulo Maurı́cio Lima de Alencastro Graça; Reinaldo Imbrózio Barbosa; Ricard Cots; Eva Cardona; Philip M. Fearnside
We test for two critical phenomena in Amazonian ecosystems: self-organized criticality (SOC) and critical transitions. SOC is often presented in the complex systems literature as a general explanation for scale invariance in nature. In particular, this mechanism is claimed to underlie the macroscopic structure and dynamics of terrestrial ecosystems. These would be inextricably linked to the action of fire, which is conceived as an endogenous ecological process. We show that Amazonian savanna fires display the scale-invariant features characteristic of SOC but do not display SOC. The same is true in Amazonian rainforests subject to moderate drought. These findings prove that there are other causes of scale invariance in ecosystems. In contrast, we do find evidence of a critical transition to a megafire regime under extreme drought in rainforests; this phenomenon is likely to determine the time scale of a possible loss of Amazonian rainforest caused by climate change.