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Alteración generalizada de las comunidades arbóreas en los bosques amazónicos intactos
William F Laurance1, Alexandre A Oliveira, Susan G Laurance
1Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panamá. laurancew@tivoli.si.edu
Nature
|March 12, 2004
Resumen
Los bosques amazónicos muestran cambios significativos y no aleatorios en la dinámica y composición de los árboles durante 20 años. Los árboles de crecimiento más rápido están aumentando, mientras que los de crecimiento más lento están disminuyendo, lo que potencialmente afecta el almacenamiento de carbono.
Área de la Ciencia:
- Ecología Ecología Ecología.
- Ciencias Forestales Ciencias Forestales Ciencias Forestales
- Biología del cambio climático Biología del cambio climático
Sus antecedentes:
- Las selvas tropicales amazónicas albergan una excepcional riqueza de especies de árboles.
- Comprender la dinámica de los bosques es crucial para la conservación y el modelado climático.
Objetivo del estudio:
- Investigar los cambios en la dinámica y composición de los árboles en los bosques amazónicos centrales no perturbados durante dos décadas.
- Identificar los patrones de cambio y los posibles impulsores, como el aumento del CO2 atmosférico.
Principales métodos:
- Análisis de datos de 18 parcelas permanentes durante 20 años.
- El monitoreo de la mortalidad de los árboles, el reclutamiento, el crecimiento, la densidad de población y el área basal.
- Comparación con un estudio independiente de ocho años en bosques cercanos.
Principales resultados:
- Se observaron aumentos significativos en la mortalidad de los árboles, el reclutamiento y las tasas de crecimiento.
- 27 de los 115 géneros de árboles abundantes mostraron cambios significativos en la densidad o área basal, 14 veces más de lo esperado por casualidad.
- Las generaciones de árboles de crecimiento más rápido (canopy / emergente) aumentaron en dominio, mientras que las generaciones de crecimiento más lento (subcanopy) disminuyeron. No se observó ningún aumento en los árboles pioneros.
Conclusiones:
- La composición del bosque amazónico está experimentando cambios rápidos y no aleatorios.
- Estos cambios pueden estar relacionados con el aumento de las concentraciones de CO2 atmosférico y otras alteraciones ambientales a gran escala.
- Los cambios observados tienen implicaciones potenciales para el almacenamiento de carbono en los bosques, la dinámica y la biodiversidad.
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