Table 5.

Correlation between prunasin concentration in roots and structural, and physiological parameters of Prunus serotina seedlings growing in 10 % low light (LL), 25 % medium light (ML), or 100 % high light (HL) of full natural sun light and in one of two competition treatment: P (three P. serotina seedlings) or Q + P + L (three Quercus petraea + six P. serotina + mulching with P. leaves). All data from three sampling dates (June, August, and September) were pooled. Chl tot – total chlorophyll content in leaf, N – nitrogen content in leaf, F _v/F _m – maximum quantum yield of PSII photochemistry, R _d. – dark respiration, A _max – maximum net CO₂ assimilation rate, E – transpiration rate, WUE – water use efficiency, PNUE – photosynthetic nitrogen use efficiency. r – Pearson’s coefficient of correlation, ^*0.01 ≤ P < 0.05, ^**0.001 ≤ P < 0.01, ^*** P < 0.001, in bold – r statistically significant (N = 17)

Structural and physiological parameters	Pearson’s coefficient of correlation
	LL	ML	HL
Chl tot (mg m−2)	−0.389	−0.253	−0.429
N (mg g−1)	0.314	0.187	0.196
N (g m−2)	0.530 *	−0.229	0.215
Fv/Fm	−0.609 *	0.170	0.355
Rd (μmol m−2 s−1)	−0.098	−0.169	−0.322
Rd (nmol g−1 s−1)	0.131	−0.426	−0.370
Amax (μmol m−2 s−1)	−0.416	0.706 **	0.338
Amax (nmol g−1 s−1)	−0.299	0.575 *	0.104
E (mmol m−2 s−1)	−0.510 *	0.541 *	0.491
WUE (μmol mmol−1)	0.510 *	−0.241	−0.680 **
PNUE (μmol mmol−1)	−0.378	0.591 *	0.380