Data/hora: 03/06/2024 06:49:01

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