Data/hora: 23/09/2024 15:57:44

Biblioteca(s): 	Embrapa Mandioca e Fruticultura.	
Data corrente: 	24/12/2016	
Data da última atualização: 	24/12/2016	
Autoria: 	FREITAS, A. D. S. de; SAMPAIO, E. V. de S. B.; RAMOS, A. P. de S.; BARBOSA, M. R. de V.; LYRA, R. P.; ARAÚJO, E. L.	
Afiliação: 	ANA DOLORES SANTIAGO DE FREITAS; EVERARDO VALADARES DE SÁ BARRETTO SAMPAIO; ANDRESA PRISCILA DE SOUZA RAMOS, CNPMF; MARIA REGINA DE VASCONCELLOS BARBOSA; ROSÂNGELA PEREIRA LYRA; ELCIDA LIMA ARAÚJO.	
Título: 	Nitrogen isotopic patterns in tropical forests along a rainfall gradient in Northeast Brazil.	
Ano de publicação: 	2015	
Fonte/Imprenta: 	Plant Soil, v. 391, p.109?122, 2015.	
ISSN: 	1573-5036	
Idioma: 	Inglês	
Conteúdo: 	Background and aims The interpretation of ecosystem nitrogen isotopic patterns is subject to controversies since there are few surveys of signals along climate gradients within the same region. We determined the effects of a rainfall gradient, under high temperatures, on the soil and plant &#948;15N signals in Northeast Brazil. Methods Nitrogen, carbon and &#948;15N signals were determined from coastal perennial to subhumid and semiarid deciduous forests to savanna ? deciduous forest transition. Results Soil C and N concentrations were linearly related and both related quadratically with mean annual rainfall while &#948;15N concentrations decreased with higher rainfall (16 to 4?). Plant &#948;15N was 1?3? lower than soil &#948;15N (&#916;&#948;15N) in all areas. Only in the deciduous forests, leaves of target species had significantly lower 15 N signals than those of non-fixing species, allowing estimation of fixation. Conclusions In the perennial forests the low signals indicated that the 15 N natural abundance method was not suitable to estimate fixation, while in the savanna ? deciduous forest transition, high signals indicated that the legume species were not fixing. The smaller &#916;&#948;15N than those reported in cooler areas and the absence of rainfall effect indicates that, when high, temperature overrides the rainfall effect.	
Thesagro: 	Nitrogênio.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Mandioca e Fruticultura (CNPMF)	
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