Foliar Litter Decomposition: A Conceptual Model with Focus on Pine (Pinus) Litter—A Genus with Global Distribution

Table 4

Relative contribution (% of total area) of different groups of C-bonds as derived from ¹³C CP-NMR spectra of newly shed foliar litter.

Litter species	Alkyl-C	Methoxy-C	O-alkyl-C	Di-O-alkyl-C	Aromatic-C	Phenolic-C	Carbonyl-C	Lit. ref.
	0–50	50–60	60–93	93–112	112–140	140–165	165–190
Scots pine	15.8	5.28	50.9	12.5	7.32	5.82	2.39	[42]
Scots pine	16.4	5.46	51.4	12.4	6.80	5.35	2.20	[42]
Jack pine	23.4	2.2	44.8	10.5	8.6	5.9	4.6	[10]
Black pine^a	16.1	5.0	61.4	—	—	5.0	3.6	[43]
Norway spruce	17.2	6.21	44.9	11.6	9.65	7.30	3.13	[42]
Black spruce	20.5	4.4	39.4	9.9	12.4	6.7	6.7	[10]
Douglas fir	23.2	1.5	45.2	8.7	9.4	6.4	5.5	[10]
Tamarack	15.9	1.7	43.3	16.5	8.0	11.1	3.5	[10]
White birch	25.8	2.4	43.7	11.7	7.1	6.3	2.9	[10]
Silver birch	23.0	5.58	43.6	12.1	6.13	5.56	3.98	[42]
Aspen	22.8	1.5	39.4	12.2	7.3	7.5	6.6	[10]
Beech	15.7	3.2	48.7	11.9	9.6	6.0	5.0	[10]

aThe investigated intervals were somewhat different.