Canopy and understory nitrogen addition increase the xylem tracheid size of dominant broadleaf species in a subtropical forest of China.
Sci Total Environ
; 642: 733-741, 2018 Nov 15.
Article
em En
| MEDLINE
| ID: mdl-29920460
ABSTRACT
Tree xylem anatomy is associated with carbon accumulation and wood quality. Increasing nitrogen (N) deposition can cause a significant effect on xylem anatomy, but related information is limited for subtropical broadleaf tree species. A 3-year field N addition experiment, with different N addition approaches (canopy and understory) and addition rates (0, 25, and 50â¯kgâ¯Nâ¯ha-1â¯yr-1), was performed beginning in 2013 in a subtropical forest of China. N addition effects on xylem tracheid (wall and lumen) size, vessel, and growth of dominant broadleaf species (Schima superba Gardn. et Champ. and Castanopsis chinensis (Sprengel) Hance) were investigated. The results showed that The effect of N addition on tracheid size was dependent on the tree species and addition approaches. Canopy N addition did not affect the tracheid size of C. chinensis, while both addition approaches increased the tracheid size of S. superba. The vessel size of both species was not affected by N addition. There was no difference in radial growth or other growth-related variables between the control and N-treated trees. These findings indicated that short-term N addition could significantly affect xylem anatomy, but might not influence tree growth. Meanwhile, understory N addition may pose challenges for mechanistic understanding and forest dynamics projection.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Florestas
/
Monitoramento Ambiental
/
Xilema
/
Nitrogênio
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article