Ecophysiological role of Embothrium coccineum, a Proteaceae species bearing cluster roots, at increasing Phosphorus availability in its rhizosphere

• M Delgado ^[2] ; A Zúñiga-Feest ^[1] ; F Borie ^[2]
  1. [1] Universidad Austral de Chile

     Universidad Austral de Chile

     Valdivia, Chile

     
  2. [2] BIOREN-UFRO Center of Amelioration and Sustainability of Volcanic Soil
• Localización: Journal of soil science and plant nutrition, ISSN-e 0718-9516, ISSN 0718-9508, Vol. 15, Nº. 2, 2015, págs. 307-320
• Idioma: inglés
• Enlaces
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• Resumen

  • Native forests in southern South America are constantly subjected to natural disasters such as volcanic eruptions. Soil affected by volcanic ash contain large amounts of total P but low P availability, as this element is strongly adsorbed to soil colloids (i.e. allophane). This lack of available P is one of the main limitations to plant growth. In this context, it is necessary an in-deep study of plant species that have developed some root physiological strategies for P acquisition. An example of this is the formation of cluster roots by Proteaceae species. Recently, information has been reported that aids to our understanding of the functioning of Proteaceae species growing in volcanic soils. The aim of this review is to discuss the ecophysiological role of Proteaceae species growing in young volcanic soils, with a special emphasis on Embothrium coccineum, a pioneer species of extremely disturbed environments. In summary, we reveal here that E. coccineum has several features that make it suitable for recovering degraded soils in south-central Chile. Some of these characteristics include its ability to survive and successfully establish in poor soils due to its specialized roots adaptation and its ability to shed its leaves under stressful conditions. According to recent evidence, E. coccineum has relatively low foliar nutrient resorption leaving at least half of the nutrients in its senescent leaves; this, in turn, promotes nutrient cycling via mineralization of its leaves. Finally, we conclude that the cluster roots of E. coccineum promote P solubilization and mineralization in the rhizosphere soil allowing for increased P availability for the plant itself and potentially also for neighbouring species.