Dissolved carbon and nitrogen release from deadwood of different tree species in various stages of decomposition

Figures & data

Table 1. Degrees of dead trees wood decomposition.

Degree	Criteria for evaluation
I	Texture intact, circular, natural color of wood, bark intact, branches < 3 cm, log leaning on branches
II	Texture intact, circular, natural color of wood, bark slightly damaged, no branches <3 cm, log begins to sink
III	Texture – larger hard fragments, circular, faded color of wood, fragmented bark, no branches <3 cm, almost entire log on the ground
IV	Texture – small pieces, oval shape, faded color of wood, no bark, no branches <3 cm, entire log on the ground
V	Texture soft and loose, oval shape, faded color of wood, no bark, no branches <3 cm, entire on the ground

Figure 1. Design of lysimeters: a – logs; b – polyethylene tube; c – silicone seal; d – plastic funnel with quartz sand; e – plastic hose; f – plastic bottle.

Table 2. Properties of leachate from deadwood different species in various decay classes (mean ± SD).

Decay classes	Species	Amount of leachate and throughfall	TC	IC	DOC	TN	pH	EC
III	Alder	3.8 ± 0.8	128.0^b ± 56.6	7.0^ab ± 2.7	120.9^b ± 55.8	6.7^ab ± 3.8	4.25^b ± 0.2	0.132^a ± 0.04
	Aspen	4.2 ± 1.1	188.2^ab ± 54.6	8.8^ab ± 1.4	179.4^ab ± 53.8	5.3^ab ± 1.9	6.27^a ± 0.4	0.264^a ± 0.20
	Ash	3.5 ± 0.7	239.0^ab ± 72.8	5.5^ab ± 3.3	233.6^ab ± 70.8	6.0^ab ± 1.0	5.26^ab ± 0.5	0.152^a ± 0.04
	Hornbeam	3.6 ± 0.9	168.4^ab ± 19.2	17.2^ab ± 15.5	150.6^b ± 22.2	3.7^ab ± 1.7	4.86^ab ± 0.6	0.298^a ± 0.10
	Birch	2.4 ± 0.7	457.9^a ± 48.3	17.8^a ± 2.4	440.0^a ± 46.2	13.2^a ± 9.1	5.45^ab ± 0.2	0.298^a ± 0.17
	Fir	3.9 ± 0.7	224.8^ab ± 58.7	5.2^b ± 3.0	219.6^ab ± 57.8	3.6^ab ± 1.8	4.75^b ± 0.5	0.169^a ± 0.11
	Spruce	4.0 ± 1.0	131.7^b ± 50.1	19.2^a± 7.9	112.6^b ± 46.6	2.4^b ± 0.7	4.27^b ± 0.3	0.204^a ± 0.08
IV	Alder	4.7 ± 1.1	1243.5^abc ± 303.1	13.3^a± 2.2	1230.2^abc± 301.1	26.1^abc± 5.0	4.19^b± 0.2	0.321^ab ± 0.08
	Aspen	4.8 ± 1.5	2704.4^a ± 542.0	16.2^a ± 1.4	2688.2^a ± 540.7	54.3^a ± 8.1	5.98^a ± 0.4	0.656^a ± 0.37
	Ash	3.9 ± 0.7	1707.5^ab ± 335.7	10.5^ab ± 3.5	1696.0^ab ± 332.6	33.9^ab ± 7.97	5.05^ab ± 0.2	0.339^ab ± 0.05
	Hornbeam	4.0 ± 1.1	2727.6^a ± 492.1	18.1^a ± 5.1	2709.5^a ± 487.2	51.6^ab ± 8.5	4.61^ab ± 0.2	0.654^a ± 0.18
	Birch	3.3 ± 1.0	378.8^bc ± 51.2	10.3^ab ± 1.6	368.5^bc ± 49.6	10.4^bc ± 2.9	5.33^a ± 0.2	0.222^b ± 0.07
	Fir	4.3 ± 1.2	396.2^bc ± 84.6	5.2^b ± 1.8	390.0^bc ± 82.8	7.2^c ± 1.9	4.03^b ± 0.4	0.263^ab ± 0.05
	Spruce	4.5 ± 1.4	178.8^c ± 31.1	10.4^ab ± 2.4	168.4^c ± 28.8	4.1^c ± 1.0	4.12^b ± 0.3	0.187^b ± 0.03
V	Alder	5.9 ± 0.9	2651.7^abc ± 437.7	22.3^a ± 2.1	2629.4^abc ± 438.7	55.3^ab ± 7.9	3.97^b ± 0.1	0.541^ab ± 0.31
	Aspen	7.2 ± 1.8	5475.6^a ± 874.6	22.7^a ± 0.9	5452.9^a ± 874.1	74.7^a ± 13.0	5.69^a ± 0.6	1.117^a ± 0.32
	Ash	5.3 ± 0.9	2182.5^abc ± 847.9	17.0^ab ± 14.3	2165.5^abc ± 860.0	35.5^abc ± 12.6	4.88^ab ± 0.2	0.684^ab ± 0.09
	Hornbeam	5.4 ± 1.3	4716.3^ab ± 1137.7	18.6^ab ± 5.6	4697.7^ab ± 1136.1	79.4^a ± 14.5	4.43^ab ± 0.2	1.237^a ± 0.179
	Birch	4.1 ± 1.1	294.4^c ± 82.3	5.8^ab ± 0.5	288.6^c ± 82.2	7.6^c ± 0.7	5.14^a ± 0.2	0.10^b ± 0.02
	Fir	4.9 ± 1.2	713.4^bc ± 193.3	5.8^ab ± 2.9	707.5^bc ± 200.1	15.9^abc ± 3.4	3.85^b ± 0.4	0.307^ab ± 0.06
	Spruce	4.7 ± 1.4	232.0^c ± 26.4	5.2^b ± 0.8	226.8^c ± 27.1	9.2^bc ± 2.3	3.91^b ± 0.3	0.173^b± 0.01
Throughfall		60.8 ± 14.6	83.8 ± 19.5	4.2 ± 0.4	79.6 ± 18.5	1.8 ± 1.1	4.21 ± 0.31	0.186 ± 0.045

TC: concentrations of total carbon (mg· L⁻¹); IC: inorganic carbon (mg· L⁻¹); TN: total nitrogen (mg· L⁻¹); DOC: dissolved organic carbon (mg· L⁻¹); EC: electrical conductivity (mS· cm⁻¹), amount of leachate and throughfall (mm· month⁻¹); III, IV, and V – decay classes; different lowercase alphabets in the upper index of the mean values mean significant differences between decay classes of wood different species

Figure 2. Dissolved organic carbon (DOC) concentration (mg · L⁻¹) for coniferous (C) and deciduous (D) species in different decay classes (III, IV, and V); different lowercase alphabets mean significant differences.

Figure 3. Total nitrogen (TN) concentration (mg · L⁻¹) for coniferous (C) and deciduous (D) species in different decay classes (III, IV, and V); different lowercase alphabets mean significant differences.

Table 3. Correlation between estimated parameters.

	IC	DOC	TN	pH	EC
IC		0.53*	0.55*	0.15	0.56*
DOC	0.53*		0.97*	0.16	0.91*
TN	0.55*	0.97*		0.12	0.89*
pH	0.15	0.16	0.12		0.18*
EC	0.56*	0.91*	0.89*	0.18*

*p < 0.05; IC: concentrations of inorganic carbon; TN: total nitrogen; DOC: dissolved organic carbon; EC: electrical conductivity.

Table 4. Results of multivariate analysis of variance based on the general linear model (GLM) for the dissolved organic carbon (DOC), including the species and decay classes.

	F	p Value
Decay classes	239.71	<0.001
Species	102.47	<0.001
Decay classes × species	36.55	<0.001

Significance effects (p < 0.05) are shown in bold.

Figure 4. Relationships between dissolved organic carbon (DOC, mg · L⁻¹) and electrical conductivity (EC, mS · cm⁻¹).

Figure 5. Relationships between total nitrogen concentration (TN, mg· L⁻¹) and electrical conductivity (EC, mS · cm⁻¹).

Figure 6. The projection of variables on a plane of the first and second factor of leachate from deadwood in various decay classes (III, IV, and V), IC: inorganic carbon; TN: total nitrogen; DOC: dissolved organic carbon; EC: electrical conductivity.