E. Garnier et al., SPECIFIC LEAF-AREA AND LEAF NITROGEN CONCENTRATION IN ANNUAL AND PERENNIAL GRASS SPECIES GROWING IN MEDITERRANEAN OLD-FIELDS, Oecologia, 111(4), 1997, pp. 490-498
Specific leaf area (the ratio of leaf area to leaf dry mass) and leaf
nitrogen concentration were measured on ten annual and nine perennial
grass species growing in two old-fields of southern France, under a su
b-humid Mediterranean climate. Specific leaf area (SLA) was found to b
e significantly higher in annuals than in perennials, but leaf nitroge
n concentration expressed on a dry mass basis (LNCm) was similar in bo
th life-forms; expressed on an area basis, leaf nitrogen concentration
(LNCa) was significantly higher in perennials. The correlation betwee
n SLA and LNCm was negative in annuals and positive in perennials, whi
le that between the inverse of specific leaf area (1/SLA) and LNCa was
positive in annuals and not significant in perennials. It is hypothes
ized that these contrasting patterns depend on whether the two compone
nts of SLA - leaf thickness and density - vary in opposite directions.
For nine of the species studied (six annuals and three perennials). r
elative growth rate data obtained in the laboratory under non-limiting
nutrient supply were available; positive correlations were found betw
een these values and both SLA and LNCm obtained in the field, suggesti
ng that the interspecific differences in structural and chemical chara
cteristics of leaves are maintained under a wide range of growing cond
itions.