Percent of builders rating a tree species as either short-lived (SL) or long-lived (LL) (and the percentage responding correctly in 1980 (n = 16) and 2008 (n = 27).
| Longevity of species (# of response in 2008) | Percent correct | |||||||
|---|---|---|---|---|---|---|---|---|
| Tree speciesz | Silvics ranky | Short | Long | Total | 1980 | 2008 | Difference | P-value |
| Aspen (S) | SL | 23 | 3 | 26 | 62.5 | 88.5 | 26.0x | 0.063 |
| Cottonwood (S) | SL | 17 | 8 | 25 | 50.0 | 68.0 | 18.0 | 0.330 |
| Jack pine (S) | SL | 23 | 3 | 26 | 50.0 | 88.5 | 38.5w | 0.011 |
| Red (Norway) pine (L) | LL | 12 | 15 | 27 | 31.3 | 55.6 | 24.3 | 0.206 |
| White pine (L) | LL | 3 | 24 | 27 | 43.8 | 88.9 | 45.1w | 0.004 |
| Red oak (L) | LL | 1 | 26 | 27 | 62.5 | 96.3 | 33.8w | 0.007 |
| Pin oak (S) | SL | 9 | 16 | 25 | 43.8 | 36.0 | −7.8 | 0.746 |
| Silver maple (S) | SL | 9 | 16 | 25 | 31.3 | 36.0 | 4.7 | 0.746 |
| Boxelder (S) | SL | 14 | 10 | 24 | 56.3 | 58.3 | 2.0 | 1.000 |
| Sugar maple (L) | LL | 4 | 23 | 27 | 31.3 | 85.2 | 53.9w | 0.001 |
| White (paper) birch (S) | SL | 24 | 2 | 26 | 68.8 | 92.3 | 23.5x | 0.085 |
| Blue spruce (L) | LL | 12 | 13 | 25 | 37.5 | 52.0 | 14.5 | 0.522 |
| Basswood (S) | SL | 19 | 6 | 25 | 37.5 | 76.0 | 38.5w | 0.022 |
| Red maple (L) | LL | 5 | 21 | 26 | 62.5 | 80.8 | 18.3 | 0.281 |
| Burr oak (L) | LL | 4 | 22 | 26 | 56.3 | 84.6 | 28.3x | 0.070 |
| Means (all species) | 48.4 | 72.5 | 24.1w | 0.0001 | ||||
↵z Boxelder (Acer negundo L.), red maple (Acer rubrum L.), silver maple (Acer saccharinum L.), sugar maple (Acer saccharum Marsh.), white (paper) birch (Betula papyrifera Marsh.), blue spruce (Picea pungens Engelm.), jack pine (Pinus banksiana Lamb.), red (Norway) pine (Pinus resinosa Aiton), white pine (Pinus strobus L.), cottonwood (Populus deltoides W. Bartram ex. Marshall), aspen (Populus tremuloides Michx.), pin oak (Quercus ellipsoidalis E.J. Hill), burr oak (Quercus macrocarpa Michx.), red oak (Quercus rubra L.), and basswood (Tilia americana L.).
↵y From USDA Forest Service Agriculture Handbook 654 (1990): SL = short lived, LL = long lived; species living <150 years classified as short lived (SL) and ≥150 years as long lived (LL).
↵x Significant at α ≤ 0.10 significance level.
↵w Significant at α ≤ 0.05 significance level.