Ecophysiology of nitrogen use in Atlantic Forest tress, São Paulo

• Grant number: 10/52292-7
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• Duration: April 01, 2011 - September 30, 2013
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Marcos Pereira Marinho Aidar
• Grantee: Marcos Pereira Marinho Aidar
• Host Institution: Instituto de Botânica. Secretaria do Meio Ambiente (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Tropical forests play an important role in regulating climate and biogeochemical cycles on Earth. The relationship between the carbon and nitrogen are well known, and N is the limiting element in the C cycle and ecosystem productivity. Besides their relevance to climate change, N is an essential nutrient for plant growth and constituent of many essential compounds. Plants differ in their requirement and ability to utilize nitrogen sources available in the environment, which allows the organization of species into functional types. In that sense, this project aims to characterize the ecophysiology of nitrogen use of dominant tree species in Montane and Submontane Ombrophylous Dense Forest and Ombrophylous Mixed Forest in São Paulo Sate. Importantly, similar patterns of nitrogen use have been found in forests in Brazil and Australia and knowledge of native ecosystems is critical to validate the model on the ecophysiology of nitrogen use by tropical tree species. The sampling areas are located in the State Parks of Serra do Mar (Ubatuba and Caraguatatuba) and Campos do Jordão. The dominant species in the study area will be selected according to their importance in structuring vegetation based on phytosociological parameters and from them, will be analyzed the following parameters: activity of nitrate reductase in vivo, leaf nitrogen and nitrate content, leaf isotopic ratio of N and C/N ratio, collection and analysis of xylem fluid, occurrence of root symbiosis and soil availability of mineral N and amino acids. The expected results should contribute to the evaluation of the model on the use of N in the tropical forest, which in turn should contribute to better understanding of the functionality of tropical forest ecosystems and how they may respond to global climate change. (AU)