The High Input of Soil Organic Matter from Dead Tree Fine Roots into the Forest Soil

Table 2

The distribution of live and dead amounts of tree fine roots (<1 mm in diameter), live/dead ratios, and dead (%) at different depths (H = humus; M = mineral soil) at the forest sites: Forsmark-1 (Coniferous, Calluna Empetrum type), Forsmark-2 (Coniferous fern type) and Forsmark-3 (Alnus swamp herb type) and Laxemar-1 (herb-rich oak forest), Laxemar-2 (Coniferous Vaccinium myrtillus type), and Laxemar-3 (Alnus shore forest type) forest sites. The live/dead ratio is calculated from the mean amounts of live and dead tree fine roots. Estimates are given as mean values ±SD (n = 31-32).

Site	Horizon	Tree roots (g m^−2)
		Live	Dead	Live/dead ratio	Dead (%)
Forsmark-1	H 0–2.5	48 ± 42	3 ± 9	13.3	6
	H 2.5–5	64 ± 29	15 ± 22	4.2	19
	H 5–10	60 ± 63	21 ± 25	2.9	26
	H 10–15	9 ± 20	9 ± 21	0.9	50
	H 15–20	2 ± 9	2 ± 12	1.0	50
	M 0–10	71 ± 96	58 ± 63	1.2	45
	M 10–20	13 ± 59	10 ± 21	1.3	43
Forsmark-2	H 0–2.5	30 ± 35	4 ± 5	7.5	12
	H 2.5–5	4 ± 12	4 ± 11	1.1	50
	H 5–10	2 ± 6	3 ± 10	0.6	60
	M 0–10	228 ± 138	136 ± 70	1.7	37
	M 10–20	51 ± 67	73 ± 60	0.7	59
	M 20–30	2 ± 8	5 ± 15	0.4	71
Forsmark-3	H 0–2.5	56 ± 58	11 ± 11	5.1	16
	H 2.5–5	46 ± 36	23 ± 21	2.0	33
	H 5–10	55 ± 52	51 ± 40	1.1	48
	H 10–15	28 ± 35	25 ± 33	1.1	47
	H 15–20	13 ± 30	9 ± 16	1.5	41
	H 20–25	3 ± 9	6 ± 22	0.5	67
	M 0–10	29 ± 73	45 ± 55	0.6	61
	M 10–20	6 ± 11	14 ± 21	0.4	70
Laxemar-1	H 0–2.5	24 ± 28	7 ± 10	3.4	23
	H 2.5–5	34 ± 37	15 ± 16	2.3	31
	H 5–10	21 ± 28	8 ± 12	2.6	28
	M 0–10	57 ± 42	48 ± 34	1.2	46
	M 10–20	3 ± 7	9 ± 23	0.3	82
Laxemar-2	H 0–2.5	102 ± 61	18 ± 23	5.6	15
	H 2.5–5	48 ± 52	17 ± 21	3.0	26
	H 5–10	10 ± 29	11 ± 30	0.9	52
	M 0–10	132 ± 69	71 ± 48	1.8	35
	M 10–20	51 ± 49	71 ± 37	0.7	58
	M 20–30	25 ± 49	31 ± 32	0.8	38
	M 30–40	4 ± 10	26 ± 34	0.2	87
Laxemar-3	H 0–2.5	14 ± 17	47 ± 79	0.3	77
	H 2.5–5	5 ± 9	38 ± 57	0.1	88
	H 5–10	1 ± 4	7 ± 19	0.1	33
	M 0–10	17 ± 25	115 ± 104	0.1	87
	M 10–20	7 ± 16	35 ± 40	0.2	85
	M 20–30	3 ± 8	21 ± 33	0.1	84
	M 30–40	2 ± 8	10 ± 14	0.2	83