Soil Characteristics and Lodgepole Pine (Pinus contorta var. latifolia) Performance Two Decades after Disk Trenching of Unburned and Broadcast-Burned Plots in Subboreal British Columbia
Table 1
Treatment1 effects2 on soil fine fraction bulk density (FFDb) and chemical properties of mineral soil at a depth of 0–10 cm after 10 and 20 years.
Burning effects
Position effects
Burning × position effects
Year
Unburned
Burned
value3
Control
Hinge
Trench
value
UB-C
UB-H
UB-T
B-C
B-H
B-T
value
Bulk density
FFDb (kg (m3)−1)
10
676 ± 25
704 ± 25
0.427
814 ± 26 b
308 ± 26 c
948 ± 26 a
<.0001
820 ± 36
262 ± 37
946 ± 36
808 ± 37
354 ± 37
950 ± 36
0.231
20
738 ± 67
627 ± 67
766 ± 67
Chemical properties
Total C (g kg−1)
10
60 ± 4
53 ± 4
0.286
19 ± 5 b
137 ± 5 a
13 ± 5 b
<.0001
20 ± 7
147 ± 7
13 ± 7
19 ± 7
127 ± 7
14 ± 7
0.238
20
24 ± 4
40 ± 4
20 ± 4
Total N (g kg−1)
10
1.5 ± 0.1
1.5 ± 0.1
0.793
0.8 ± 0.1 b
3.0 ± 0.1 a
0.7 ± 0.1 b
<.0001
0.8 ± 0.2
3.1 ± 0.2
0.6 ± 0.2
0.8 ± 0.2
2.9 ± 0.2
0.7 ± 0.2
0.709
20
0.9 ± 0.1
1.3 ± 0.1
0.9 ± 0.1
C/N
10
30 ± 1
29 ± 1
0.443
23 ± 1
46 ± 1
20 ± 1
<.0001
24 ± 2
47 ± 2
20 ± 2
23 ± 2
44 ± 2
20 ± 2
0.688
20
26.2 ± 1.1
30.2 ± 1.1
23.4 ± 1.1
NH4 - N (mg kg−1)
10
20.3 ± 1.1
13.8 ± 1.1
n/a
6.4 ± 1.3
39.6 ± 1.3
5.2 ± 1.3
n/a
5.3 ± 1.8 c
49.3 ± 1.8 a
6.5 ± 1.8 c
7.5 ± 1.8 c
30.0 ±1.8 b
3.9 ± 1.8 c
<0.0001
20
3.9 ± 0.8
5.1 ± 0.8
4.5 ± 0.8
NO3 - N (mg kg−1)
10
6.4 ± 1.3
6.5 ± 1.3
0.953
6.2 ± 1.2
7.2 ± 1.2
6.1 ± 1.2
0.644
5.0 ± 1.7
8.6 ± 1.7
5.7 ± 1.7
7.4 ± 1.7
5.8 ± 1.7
6.5 ± 1.7
0.165
20
0.09 ± 0.06
0.01 ± 0.06
0.12 ± 0.06
Min-N (mg kg−1)
10
64 ± 12
60 ± 12
0.753
29 ± 10 b
118 ± 10 a
39 ± 10 b
<.0001
30 ± 14
137 ± 14
25 ± 14
29 ± 14
99 ± 14
53 ± 14
0.081
20
10 ± 4
24 ± 4
9 ± 4
Avail. P (mg kg−1)
10
64 ± 12
58 ± 12
0.727
61 ± 9 ab
78 ± 9 a
45 ± 9 b
0.0003
62 ± 13
78 ± 13
52 ± 13
60 ± 13
78 ± 13
37 ± 13
0.521
20
66 ± 22
62 ± 22
63 ± 22
pH
10
4.61 ± 0.05
4.59 ± 0.05
0.822
4.59 ± 0.05 b
4.45 ± 0.05 b
4.76 ± 0.05 a
0.0006
4.58 ± 0.07
4.40 ± 0.07
4.80 ± 0.07
4.60 ± 0.07
4.50 ± 0.07
4.73 ± 0.07
0.420
20
4.74 ± 0.06
4.64 ± 0.06
4.80 ± 0.06
CEC (cmolc kg−1)
10
22.8 ± 1.4
21.1 ± 1.4
0.416
14.7 ± 1.7 b
39.7 ± 1.7 a
11.4 ±1.7 b
<.0001
15.5 ± 2.4
40.5 ± 2.4
12.3 ± 2.4
13.9 ± 2.4
38.9 ± 2.4
10.5 ± 2.4
0.999
20
5.1 ± 0.6
7.2 ± 0.6
4.7 ± 0.6
Exch. Ca (cmolc kg−1)
10
6.5 ± 1.7
8.4 ± 1.7
0.452
3.7 ± 2.1
14.8 ± 2.1
3.8 ± 2.1
0.002
3.6 ± 3.0
12.0 ± 3.0
3.9 ± 3.0
3.8 ± 3.0
17.6 ± 3.0
3.7 ± 3.0
0.568
20
1.8 ± 0.4
3.1 ± 0.4
1.6 ± 0.4
Exch. Mg (cmolc kg−1)
10
1.15 ± 0.09
1.07 ± 0.09
0.514
0.68 ± 0.10 b
2.00 ± 0.10 a
0.64 ± 0.10 b
<.0001
0.72 ± 0.14
2.08 ± 0.14
0.66 ± 0.14
0.65 ± 0.14
1.93 ± 0.14
0.63 ± 0.14
0.902
20
0.02 ± 0.01
0.09 ± 0.01
0.01 ± 0.01
Exch. K (cmolc kg−1)
10
0.43 ± 0.04
0.39 ± 0.04
0.438
0.28 ± 0.04
0.69 ± 0.04
0.26 ± 0.04
<.0001
0.27 ± 0.06
0.77 ± 0.06
0.26 ± 0.06
0.28 ± 0.06
0.61 ± 0.06
0.27 ± 0.06
0.248
20
0.13 ± 0.02
0.22 ± 0.02
0.13 ± 0.02
Base satn. (%)
10
35 ± 4
44 ± 4
0.180
32 ± 5
44 ± 5
42 ± 5
0.269
30 ± 8
36 ± 8
39 ± 8
34 ± 8
51 ± 8
46 ± 8
0.792
20
35 ± 4
44 ± 4
38 ± 4
E.C. (mS/cm)
10
0.29 ± 0.02
0.33 ± 0.02
0.078
0.26 ± 0.02 b
0.43 ± 0.02 a
0.23 ± 0.02 b
<.0001
0.28 ± 0.03
0.48 ± 0.03
0.24 ± 0.03
0.25 ± 0.03
0.38 ± 0.03
0.23 ± 0.03
0.335
20
0.15 ± 0.02
0.17 ± 0.02
0.14 ± 0.02
1 UB-C is unburned control; UB-H is unburned hinge; UB-T is unburned trench; B-C is burned control; B-H is burned hinge; B-T is burned trench. 2Values are mean ± one standard error. Letters are supplied only for variables where the Bonferroni test found significant differences between individual means within a given year. Means having the same letter do not differ significantly () within the given year according to the Bonferroni test. 3 values in bold indicate .
