Data/hora: 23/09/2024 03:58:27

Biblioteca(s): 	Embrapa Meio Ambiente.	
Data corrente: 	26/07/2018	
Data da última atualização: 	26/07/2018	
Autoria: 	DAVIDSON, E. A.; MARKEWITZ, D.; FIGUEIREDO, R. de O.; CAMARGO, P. B. de.	
Afiliação: 	ERIC A DAVIDSON, University of Maryland Center for Environmental Science; DANIEL MARKEWITZ, University of Georgia; RICARDO DE OLIVEIRA FIGUEIREDO, CNPMA; PLINIO BARBOSA DE CAMARGO, CENA-USP.	
Título: 	Nitrogen fixation inputs in pasture and early successional forest in the Brazilian Amazon region: evidence from a claybox mesocosm study.	
Ano de publicação: 	2018	
Fonte/Imprenta: 	Journal of Geophysical Research: Biogeosciences, v. 123, n. 2, p. 712-721, 2018.	
DOI: 	https://doi.org/10.1002/2017JG004103	
Idioma: 	Inglês	
Conteúdo: 	The role of biological nitrogen fixation (BNF) during secondary forest succession and in tropical pastures has been investigated and debated for several decades. Here we present results of a replicated experimental study in a degraded cattle pasture of eastern Amazonia using mass balance and a 15N tracer in lined soil pit mesocosms with three treatments: (1) plant-free control plots, (2) pasture grass Brachiaria brizantha, and (3) regrowth of early successional secondary forest species. Accumulation of N in grass biomass slightly exceeded estimates of net N mineralization from the plant-free control plots but was within the margin of error, so inputs of BNF may not have been needed. In contrast, the secondary forest vegetation accumulated about 3 times as much biomass N annually as the net N mineralization estimate, suggesting at least some role for BNF. Based on isotopic and mass measurements of N-fixing species, BNF was estimated to contribute at least 27 ± 3% of mean annual plant uptake in the secondary forest regrowth vegetation plots. Although BNF is probably important for recuperation of tropical secondary forests following land use change, the majority of the N taken up by both grasses and secondary forest regrowth arose from mineralization of the stocks of soil N.	
Thesagro: 	Argila; Fixação de nitrogênio; Floresta secundária; Pastagem.	
Thesaurus Nal: 	Clay; Forest succession; Nitrogen fixation; Tropical pastures.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
Registro original: 	Embrapa Meio Ambiente (CNPMA)	
Exemplares: 	CNPMA - (16150-1) - UPC - AP - DD -  -  -  - DIS