Produção Nacional
Nitrogen Balance of a Floodplain Forest of the Amazon River: The Role of Nitrogen Fixation
2010; Springer Nature; Linguagem: Inglês
10.1007/978-90-481-8725-6_14
ISSN2196-971X
AutoresJürgen Kern, Heidi Kreibich, Matthias Koschorreck, Assad Darwich,
Tópico(s)Environmental and biological studies
ResumoThe high biomass production in the várzea depends on a high supply of nitrogen, one of the most important macronutrients. There are three main paths for nitrogen to reach the floodplain. Nitrogen derives firstly from the water of the Amazon River when it inundates the floodplain during rising water, secondly from atmospheric deposition, and thirdly from biological N2 fixation (Kern and Darwich 1997). Atmospheric N2 is fixed in various ecotopes, primarily on high elevational ranges of the floodplain. At an elevational range of 22–25 m a.s.l. the forest under study is located on a ridge on Marchantaria Island. It is influenced by the water level of the Camaleão Lake, leading to an average inundation period between 4.7 and 7.6 months per year. In this most advanced successional stage of phytocoenoses, pathways of nitrogen input and output were studied next to Lake Camaleão on Marchantaria Island (Kreibich et al. 2006). This island is not affected hydrochemically by non-inundated upland (terra firme). Interpretation of the results are therefore restricted to exclusive white-water habitats of the central Amazon floodplain.
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