Fine roots are the dominant source of recalcitrant plant litter in sugar maple-dominated northern hardwood forests.
New Phytol
; 208(3): 715-26, 2015 Nov.
Article
em En
| MEDLINE
| ID: mdl-26073624
ABSTRACT
Most studies of forest litter dynamics examine the biochemical characteristics and decomposition of leaf litter, but fine roots are also a large source of litter in forests. We quantified the concentrations of eight biochemical fractions and nitrogen (N) in leaf litter and fine roots at four sugar maple (Acer saccharum)-dominated hardwood forests in the north-central United States. We combined these results with litter production data to estimate ecosystem biochemical fluxes to soil. We also compared how leaf litter and fine root biochemistry responded to long-term simulated N deposition. Compared with leaf litter, fine roots contained 2.9-fold higher acid-insoluble fraction (AIF) and 2.3-fold more condensed tannins; both are relatively difficult to decompose. Comparatively, leaf litter had greater quantities of more labile components nonstructural carbohydrates, cellulose and soluble phenolics. At an ecosystem scale, fine roots contributed over two-thirds of the fluxes of AIF and condensed tannins to soil. Fine root biochemistry was also less responsive than leaf litter to long-term simulated N deposition. Fine roots were the dominant source of difficult-to-decompose plant carbon fractions entering the soil at our four study sites. Based on our synthesis of the literature, this pattern appears to be widespread in boreal and temperate forests.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Solo
/
Florestas
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Raízes de Plantas
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Folhas de Planta
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Acer
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article