Table 3.

Effects of competitor identity on total biomass, growth indices, inorganic and organic N net uptake capacity, and N metabolite levels of Fagus sylvatica, Quercus robur, Pinus sylvestris, Prunus serotina, and Robinia pseudoacacia seedlings.

Biomass and growth índices						N net uptake capacity				N metabolites
										Total soluble		Total soluble
										amino acid-N		protein-N
	Total biomass	Root: shoot ratio	RGR	SLA	SRL	${\mathrm{N}\mathrm{H}}_{\mathrm{4}}^{\mathrm{+}}$	${\mathrm{N}\mathrm{O}}_{\mathrm{3}}^{\mathrm{-}}$	Gln-N	Arg-N	Leaves	Fine roots	Leaves	Fine roots
Fagus	n.s.	n.s.	Prunus <Robinia	n.s.	n.s.	n.s.	Prunus <Robinia	Prunus <Robinia	n.s.	n.s.	n.s.	n.s.	n.s.
Quercus	Prunus <Robinia	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	Prunus <Robinia (a)	n.s.	n.s.
Pinus	n.s.	n.s.	n.s.	n.s.	Robinia <Prunus	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.
Prunus	n.s.	n.s.	n.s.	Fagus <Quercus	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.	n.s.
Robinia	n.s.	n.s.	n.s.	Fagus <Quercus, Pinus	n.s.	n.s.	n.s.	Quercus <Fagus, Pinus (a)	n.s.	n.s.	Quercus, Pinus <Fagus (b)	n.s.	n.s.

Species A < species B, seedlings competing with species A had significantly lower values than seedlings competing with species B; n.s., no significant differences between competitor identities. Total biomass (g), root:shoot ratio, ratio of belowground biomass to aboveground biomass; RGR, relative growth rate (g dw g^-1 dw d^-1); SLA, specific leaf area (cm² g^-1 dw); SRL, specific root length (cm g^-1 dw); N net uptake capacity (nmol N g^-1 fw h^-1), ${\mathit{N}\mathit{H}}_{\mathit{4}}^{\mathit{+}}$, ammonium; ${\mathit{N}\mathit{O}}_{\mathit{3}}^{\mathit{-}}$, nitrate; Gln-N, glutamine; Arg-N, arginine; total soluble amino acid-N (mg amino acid-N g^-1 dw); total soluble protein-N (mg protein-N g^-1 dw). (a) Only at high soil N availability. (b) Only at low soil N availability. No letter: effect of competition regardless of soil N availability.