Variations in Amazon forest productivity correlated with foliar nutrients and modelled rates of photosynthetic carbon supply

• Autor(a) principal: Mercado, Lina
• Data de Publicação: 2011
• Outros Autores: Patiño, Sandra, null, Tomas, Fyllas, Nikolaos M., Weedon, Graham P., Sitch, Stephen A., Quesada, Carlos Alberto, Phillips, Oliver L., Aragao, L. E.O.C., Malhi, Yadvinder Singh, Dolman, A. Johannes, Restrepo-Coupé, Natalia, Saleska, Scott Reid, Baker, Timothy R., Almeida, Samuel Miranda, Higuchi, Niro, Lloyd, Jon
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional do INPA
• Texto Completo: https://repositorio.inpa.gov.br/handle/1/16227
• topic: Aboveground Biomass; Aboveground Production; Climate Change; Community Composition; Forestry Production; Growth Rate; Nutrient Availability; Nutrient Limitation; Photosynthesis; Soil Nutrient; Tropical Forest; Underpinning; Amazon Basin

The rate of above-ground woody biomass production, WP, in some western Amazon forests exceeds those in the east by a factor of 2 or more. Underlying causes may include climate, soil nutrient limitations and species composition. In this modelling paper, we explore the implications of allowing key nutrients such as N and P to constrain the photosynthesis of Amazon forests, and also we examine the relationship between modelled rates of photosynthesis and the observed gradients in WP. We use a model with current understanding of the underpinning biochemical processes as affected by nutrient availability to assess: (i) the degree to which observed spatial variations in foliar [N] and [P] across Amazonia affect stand-level photosynthesis; and (ii) how these variations in forest photosynthetic carbon acquisition relate to the observed geographical patterns of stem growth across the Amazon Basin. We find nutrient availability to exert a strong effect on photosynthetic carbon gain across the Basin and to be a likely important contributor to the observed gradient in WP. Phosphorus emerges as more important than nitrogen in accounting for the observed variations in productivity. Implications of these findings are discussed in the context of future tropical forests under a changing climate. © 2011 The Royal Society.