Appendix C. Test statistics for environmental variables.
TABLE C1. Test statistics for environmental variables within the young stands (N = 23). The z-value is the test statistics in GLM with poison and binomial error terms, t-value in GLM with Gaussian error term (linear model), and V denotes the test statistics in Wilcoxon signed rank test used for the pairwise comparison of variables in two plots (at 10 and 80 m from the edge) for variables with problematic distributions (See also Table 1).
Variable |
Error term |
Test |
β |
P value |
Residual |
df |
Coarse logs (>25 cm) (m) |
Poission |
z = 2.8 |
0.74 |
0.0041 |
30 |
68 |
Fine logs (<25 cm) (m) |
Poission |
z = –3.0 |
–0.78 |
0.0024 |
51 |
68 |
Coarse stumps (>25 cm) (n:o) |
Poission |
z = 1.1 |
0.011 |
0.26 |
92 |
68 |
Fine stumps (<25 cm) (n:o) |
Poission |
z = 0.67 |
0.071 |
0.51 |
98 |
68 |
Boulders (>0.5 m) (frequency 0-20) |
Binomial |
z = 2.6 |
0.21 |
0.010 |
91 |
68 |
Dry ground (frequency 0–20) |
Binomial |
z = 2.2 |
0.026 |
0.025 |
79 |
68 |
Peatmoss cover (frequency 0–20) |
Binomial |
z = –1.2 |
–0.15 |
0.23 |
128 |
68 |
Canopy cover (%) |
V = 17 |
– |
0.086 |
– |
– |
|
Shrub cover (%) |
V = 71.5 |
– |
0.53 |
– |
– |
|
Understory cover (%) |
V = 47.5 |
– |
0.92 |
– |
– |
|
Bryophyte cover (%) |
V = 87.5 |
– |
0.029 |
– |
– |
|
Basal area spruce (m2/ha-1) |
V = 116 |
– |
1.0 |
– |
– |
|
Basal area pine (m2/ha-1) |
V = 84 |
– |
0.28 |
– |
– |
|
Basal area decidous trees (m2/ha-1) |
V = 1 |
– |
0.058 |
– |
– |
|
Height of trees (m) |
Gaussian |
t = –0.32 |
–0.05 |
0.28 |
– |
67 |