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La supervivencia glacial de los árboles boreales en el norte de Escandinavia
Laura Parducci1, Tina Jørgensen, Mari Mette Tollefsrud
1Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
Science (New York, N.Y.)
|March 3, 2012
Resumen
Los coníferos sobrevivieron en Escandinavia durante la última edad de hielo, desafiando la creencia de que se recolonizaron después de que la capa de hielo se retiró. La evidencia muestra el ADN de árboles antiguos en los sedimentos del lago noruego, lo que indica la supervivencia en refugios libres de hielo.
Área de la Ciencia:
- La paleobotánica es la paleobotánica.
- Palinología Cuaternaria Palinología Cuaternaria
- Ecología Molecular Ecología Molecular
Sus antecedentes:
- La opinión predominante postula que Escandinavia estaba desprovista de árboles durante la última glaciación, con la recolonización que ocurrió hace ~ 9000 años.
- Se plantea la hipótesis de refugios libres de hielo en Escandinavia durante el último período glacial, pero carecen de evidencia botánica directa.
Objetivo del estudio:
- Investigar la presencia y supervivencia de las coníferas en Escandinavia durante la última glaciación.
- Desafiar la línea de tiempo establecida de la recolonización de bosques postglaciales en la península escandinava.
Principales métodos:
- Análisis de los raros haplotipos de ADN mitocondrial (ADNmt) del abeto.
- La datación por radiocarbono de ADN antiguo extraído de los sedimentos de los lagos y el polen.
- Identificación del ADN de cloroplasto de pino y abeto en núcleos de sedimentos.
Principales resultados:
- Descubrimiento de un único haplotipo de ADNmt del abeto escandinavo con alta frecuencia en el oeste de Noruega.
- Detección del ADN de este haplotipo de abeto en los sedimentos del lago Trøndelag que datan de hace ~ 10.300 años.
- Identificación de ADN de pino y de abeto en sedimentos del noroeste de Noruega que datan de hace aproximadamente 22.000 y 17.700 años, respectivamente, cerca del refugio de Andøya.
Conclusiones:
- Las coníferas, incluidos el pino y el abeto, sobrevivieron a la última glaciación dentro de refugios libres de hielo en Escandinavia.
- Estos hallazgos requieren una revisión de los modelos actuales con respecto a la supervivencia de los árboles y los patrones de dispersión en respuesta al cambio climático pasado.
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