Table 2.
Stand structure, density, diameter, basal area, and tree height attributes of the seven research sites where we conducted studies of SNC severity in western Oregon, 2016–2017.
| Trees per plot2 | Trees per Ha | Average DBH (cm) | Basal Area (m2/Ha) | Average Tree Height (m) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Site | Plot | Douglas-fir | Other Trees | Douglas-fir | Other Trees | Douglas-fir | Other Trees | Douglas-fir | Other Trees | Douglas-fir | Other Trees | |
| CH1 | Mature | 3 | 4 | 133 | 160 | 112.9 | 43.6 | 119.5 | 34.4 | 54.7 | 29.5 | |
| Young | 17 | 0 | 680 | 0 | 28.3 | NA3 | 42.9 | NA | 20.0 | NA | ||
| KT1 | Mature | 2 | 1 | 93 | 27 | 158.4 | 43.7 | 176.3 | 6.0 | 62.3 | 28.0 | |
| Young | 3 | 0 | 120 | 0 | 23.8 | NA | 5.4 | NA | 14.6 | NA | ||
| WC1 | Mature | 2 | 8 | 93 | 307 | 107.0 | 21.2 | 68.3 | 11.0 | 57.7 | NA | |
| Young | 9 | 1 | 360 | 40 | 10.3 | 2.9 | 3.0 | 0.0 | 6.0 | 4.0 | ||
| MM1 | Mature | 4 | 6 | 173 | 253 | 85.1 | 15.7 | 93.7 | 5.6 | 53.5 | 12.0 | |
| Young | 15 | 19 | 600 | 760 | 9.8 | 8.7 | 4.6 | 4.5 | 8.1 | 7.7 | ||
| FC1 | Mature | 4 | 10 | 173 | 400 | 78.6 | 9.4 | 83.6 | 2.2 | 66.0 | 6.4 | |
| Young | 6 | 36 | 240 | 1440 | 24.4 | 4.0 | 11.2 | 1.8 | 10.6 | 5.9 | ||
| SG1 | Mature | 2 | 5 | 67 | 213 | 156.4 | 42.6 | 133.2 | 30.8 | 54.1 | 21.4 | |
| Young | 10 | 8 | 400 | 320 | 15.5 | 14.9 | 7.5 | 5.5 | 9.4 | 8.8 | ||
| TC1 | Mature | 4 | 13 | 173 | 533 | 81.4 | 18.3 | 88.4 | 13.8 | 45.7 | 11.5 | |
| Young | 4 | 32 | 160 | 1280 | 9.7 | 8.5 | 1.2 | 7.2 | 7.8 | 7.1 | ||
The abbreviation of study sites is Cascade Head (CH), Woods Creek (WC), and Klickitat Mountain (KT), Moose Mountain (MM), Falls Creek (FC), Soapgrass Mountain (SG), and Toad Creek (TC).
For each of mature stands, we investigated three 8.9m radius plots centered with our sample tree, and averaged all 3 plots data to represent mature stand. For each of young stands, because the trees are closed to EPA weather station and the young trees grow evenly in stand, so we only investigated one 8.9m radius plot centered with EPA weather station. Dead trees and saplings were not included.
“NA” means no data or not sufficient data to present.
Three sampled trees for the mature stands are spaced at least 10m apart from each other (mostly >20m), and the three sampled trees for the young stands were located in proximity to a weather station at different orientations and were spaced at least 3 m apart from each other (mostly >5m).