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Descripción
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| Soil CO2 efflux is an important component of the carbon cycle (C) that constitutes the largest C emission from ecosystems to the atmosphere. The CO2 emanates mainly from root and associated mycorrhizal respiration (autotrophic component), and decomposition of aboveground and root litter by microorganisms and soil fauna (heterotrophic component). Previous studies have estimated that contribution of autotrophic respiration to total soil CO2 efflux ranged 30-90%. This wide variation is partly due to the different sensitivities of both respiratory components to soil temperature, water content, resource quality, and current photosynthetic rate. Since autotrophic and heterotrophic respiration may probably show different behaviors in response to environmental variables, it is necessary to accurately estimate their relative contribution according to the characteristics of each site. Only in this way the implications of environmental changes for soil C cycling and sequestration in forest ecosystems can be assessed. This study aimed to reveal differences in the contribution of autotrophic respiration to total respiration in a broad-leaved (Quercus pyrenaica Willd) and in a coniferous forest (Pinus sylvestris L.) inside their ecotonal area in the Guadarrama National Park (Spain). We are conducting a trenching experiment since April 2014. We quantified soil CO2 efflux in trenched and untrenched plots in each forest, using the static chamber method connected to a WMA-4 IRGA. Preliminary results for the first nine months of the experiment show that soil temperature and water content control soil respiration under Pyrenean oak and Scots pine, not being statistically different. Respiration of trenched and control plots under Scots pine are not different although they show distinct responses to soil temperature. Trenched plots under Pyrenean oak emitted less than control ones. Additionally, there are seemingly seasonal changes in both components of soil respiration. | |
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Internacional
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No |
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Nombre congreso
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REMEDIA IV Workshop sobre Mitigación de gases de efecto invernadero provenientes del sector agroforestal |
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Tipo de participación
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960 |
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Lugar del congreso
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Madrid |
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Revisores
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Si |
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ISBN o ISSN
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978-84-606-6727-8 |
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DOI
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Fecha inicio congreso
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23/04/2015 |
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Fecha fin congreso
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25/04/2015 |
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Desde la página
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9 |
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Hasta la página
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9 |
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Título de las actas
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Libro de Abstracts REMEDIA IV Workshop |