Delta15N of soil N and plants in a N-saturated, subtropical forest of southern China.
Rapid Commun Mass Spectrom
; 24(17): 2499-506, 2010 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-20740523
ABSTRACT
We investigated the delta(15)N profile of N (extractable NH(4)(+), NO(3)(-), and organic N (EON)) in the soil of a N-saturated subtropical forest. The order of delta(15)N in the soil was EON > NH(4)(+) > NO(3)(-). Although the delta(15)N of EON had been expected to be similar to that of bulk soil N, it was higher than that of bulk soil N by 5 per thousand. The difference in delta(15)N between bulk soil N and EON (Delta(15)N(bulk-EON)) was correlated significantly with the soil C/N ratio. This correlation implies that carbon availability, which determines the balance between N assimilation and dissimilation of soil microbes, is responsible for the high delta(15)N of EON, as in the case of soil microbial biomass delta(15)N. A thorough delta(15)N survey of available N (NH(4)(+), NO(3)(-), and EON) in the soil profiles from the organic layer to 100 cm depth revealed that the delta(15)N of the available N forms did not fully overlap with the delta(15)N of plants. This mismatch in delta(15)N between that of available N and that of plants reflects apparent isotopic fractionation during N uptake by plants, emphasizing the high N availability in this N-saturated forest.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Solo
/
Compostos de Nitrogênio
/
Folhas de Planta
/
Isótopos de Nitrogênio
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article