Table 1. Characteristics of stands and trees containing cavities in balsam fir (Abies balsamea), spruce (Picea sp.), and clearcut stands in the Chauvin and Martin-Valin controlled wildlife harvesting zones, Quebec, Canada, 2004–2005. The acronym “dbh” stands for diameter at breast height. “Spruce sp.” indicates snags that could be identified only with regard to genera, whereas “conifer sp.” indicates snags that could not be identified at all.
| |
| |
| Characteristics |
Balsam fir stands |
Spruce stands |
Clearcuts |
P |
| |
| No. of living trees sampled |
2532 |
2224 |
124 |
|
| No. of dead trees sampled |
1113 |
1188 |
565 |
|
| No. of cavities found |
59 |
21 |
30 |
|
| Cavity-tree density (no./ha)† |
|
|
|
|
| Total |
6.5 (± 1.1) a |
1.7 (± 0.5) b |
1.5 (± 0.3) b |
< 0.0001 |
| Excavated by woodpecker |
3.3 (± 0.7) a |
0.9 (± 0.4) b |
0.9 (± 0.4) ab |
0.003 |
| Nonexcavated |
3.2 (± 0.7) a |
0.8 (± 0.2) b |
0.7 (± 0.2) ab |
0.006 |
| Mean cavity-tree dbh (cm)† |
|
|
|
|
| Total |
30.2 (± 1.1) a |
25.7 (± 1.7) b |
30.8 (± 1.5) ab |
0.032 |
| Excavated by woodpecker |
28.3 (± 1.5) ab |
24.4 (± 2.3) a |
33.7 (± 1.9) b |
0.013 |
| Nonexcavated |
32.0 (± 1.6) |
26.6 (± 2.3) |
27.9 (± 2.2) |
0.102 |
| Mean cavity-tree height (m)† |
|
|
|
|
| Total |
5.1 (± 0.5) |
5.5 (± 0.7) |
4.9 (± 0.7) |
0.350 |
| Excavated by woodpecker |
7.1 (± 0.8) |
6.9 (± 1.2) |
6.3 (± 1.0) |
0.310 |
| Nonexcavated |
3.2 (± 0.4) |
4.4 (± 0.6) |
3.4 (± 0.7) |
0.328 |
| Distribution of canopy closure index (%)‡ |
|
|
|
0.005 |
| Clear (1) |
23.7 (-) |
35.3 |
78.6 (+) |
|
| Partially closed (2) |
47.4 |
11.8 (-) |
14.3 (-) |
|
| Closed (3) |
28.9 |
52.9 |
7.1 (-) |
|
| Distribution of decay-class (%)‡ |
|
|
|
0.08 |
| 5 |
0 |
4.3 |
11.5 |
|
| 6 |
38.1 |
21.7 |
38.5 |
|
| 7 |
42.9 |
54.3 |
19.2 |
|
| 8 |
19.0 |
19.6 |
30.8 |
|
| Distribution of cavity-tree species (%)‡ |
|
|
|
0.4221 |
| Excavated by woodpecker |
|
|
|
|
Balsam fir |
61.5 |
66.7 |
23.1 |
|
White birch (Betula papyrifera) |
0 |
11.1 |
46.2 |
|
White spruce (Picea glauca) |
0 |
0 |
0 |
|
Black spruce (Picea mariana) |
15.4 |
22.2 |
7.7 |
|
Spruce sp. |
7.7 |
0 |
23.1 |
|
Conifer sp. |
15.4 |
0 |
0 |
|
| Nonexcavated |
|
|
|
|
Balsam fir |
54.2 |
61.5 |
69.2 |
|
White birch |
12.5 |
0 |
7.7 |
|
White spruce |
8.3 |
0 |
0 |
|
Black spruce |
0 |
15.4 |
0 |
|
Spruce sp. |
4.2 |
7.7 |
15.4 |
|
Conifer sp. |
20.8 |
15.4 |
7.7 |
|
|
| |
†Standard errors are in parentheses, a nonparametric Kruskal-Wallis test was conducted, and post-hoc pairwise comparisons were determined using Mann-Whitney U tests. Different letters indicate significant differences among treatments.
‡Chi-square tests were conducted for differences among distributions, and “+” and “-” indicate values that were significantly higher or lower than expected values.
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