Table 3.

Results from pairwise comparisons for enrichment factors ε¹⁵N, ε¹³C and nitrogen concentration (mmol g d. wt^–1) between Epipactis species and sporocarps of ECM ascomycetes, ECM basidiomycetes and SAP fungi and their autotrophic references using the Mann-Whitney U-test

Species	ε15N		ε13C		N concentration
	U	P	U	P	U	P
Epipactis helleborine (L.) Crantz	300	<0·001	265	<0·001	280	<0·001
Epipactis helleborine subsp. neerlandica (Verm.) Buttler	75	<0·001	67	0·008	66	0·011
Epipactis microphylla (Ehrh.) Sw.	75	<0·001	75	<0·001	48	0·395
Epipactis purpurata Sm.	75	<0·001	75	<0·001	75	<0·001
Epipactis distans Arv.-Touv.	75	<0·001	75	<0·001	73	<0·001
Epipactis leptochila (Godfery) Godfery	75	<0·001	75	<0·001	75	<0·001
Epipactis muelleri Godfery	75	<0·001	75	<0·001	75	<0·001
Epipactis neglecta (Kümpel) Kümpel	75	<0·001	75	<0·001	75	<0·001
Epipactis atrorubens (Hoffm.) Besser*	275	<0·001	246	<0·001	275	<0·001
Epipactis distans Arv.-Touv.*	48	0·004	47	0·002	45	0·008
Epipactis fibri Scappat. and Robatsch*	348	<0·001	344	<0·001	287·5	0·001
Epipactis gigantea Douglas ex Hook.*	93·5	0·003	14	0·017	99	<0·001
Epipactis helleborine (L.) Crantz*	1596	<0·001	1329	<0·001	1469	<0·001
Epipactis leptochila (Godfery) Godfery*	16	0·029	16	0·029	16	0·029
Epipactis palustris (L.) Crantz*	48	0·001	26	0·862	NA	NA
Sporocarps of ECM ascomycetes	6155	<0·001	6132	<0·001	5549	<0·001
Sporocarps of ECM basidiomycetes	5209	<0·001	5835	<0·001	4776	<0·001
Sporocarps of SAP fungi	2300	<0·001	2686	<0·001	2302	<0·001

^*Epipactis species for which data have been extracted from the literature.