DecAID Repository - List of Stand Structural Conditions

DecAID uses three generalized structural conditions (QMD = quadratic mean diameter):

Here are the equivalents in terms of the 26 SHP structural conditions listed by O'Neil et al. (2001) (as variously listed above under the wildlife generalized structural conditions), although the inventory data do not provide information on number of canopy layers:

SHP Forest Structural Conditions	DecAID Structural Condition Class
1 Grass/Forb Open	Open canopy
2 Grass/Forb Closed	Open canopy
3 Shrub/seedling Open	Open canopy
4 Shrub/seedling Closed	Open canopy
5 Sapling/Pole Open	Open canopy
6 Sapling/Pole Moderate	Open canopy
7 Sapling/Pole Closed	Open canopy
8 Small tree single story open	Small/medium trees
9 Small tree single story moderate	Small/medium trees
10 Small tree single story closed	Small/medium trees
11 Small tree multi-story open	Small/medium trees
12 Small tree multi-story moderate	Small/medium trees
13 Small tree multi-story closed	Small/medium trees
14 Large tree single story open	Larger trees
15 Large tree single story moderate	Larger trees
16 Large tree single story closed	Larger trees
17 Medium tree multi-story open	Small/medium trees
18 Medium tree multi-story moderate	Small/medium trees
19 Medium tree multi-story closed	Small/medium trees
20 Large tree single story open	Larger trees
21 Large tree single story moderate	Larger trees
22 Large tree single story closed	Larger trees
23 Large tree multi-story open	Larger trees
24 Large tree multi-story moderate	Larger trees
25 Large tree multi-story closed	Larger trees
26 Giant tree multi-story	Larger trees

Source for SHP Forest Structural Conditions:
O'Neil, T. A., K. A. Bettinger, M. Vander Heyden, B. G. Marcot, C. Barrett, T. K. Mellen, W. M. Vander Haegen, D. H. Johnson, P. J. Doran, L. Wunder, and K. M. Boula. 2001. Structural conditions and habitat elements of Oregon and Washington. Pp. 115-139 in: D. H. Johnson and T. A. O'Neil, eds. Wildlife-habitat relationships in Oregon and Washington. Oregon State University Press, Corvallis OR.

Here is a more detailed crosswalk of the three DecAID generalized structural conditions with the original set of SHP structural condition classes (O'Neil et al. 2001, cited above):

The postfire structural condition can include the following specific structural stages (from the Oregon-Washington Species-Habitat Project, O'Neil et al. 2001, cited above):

1) Grass/Forb - Open
Grass/Forb dominated with <70% coverage by grasses and forbs. Shrubs and small seedlings may be present, but do not dominate stand, (seedlings < 10% canopy cover), and there can be remnant trees (trees remaining from the previous stand) that can provide <10% canopy cover.

2) Grass/Forb - Closed
Grass/Forb dominated with >70% coverage by grasses and forbs. Shrubs and small seedlings may be present, but do not dominate stand, (seedlings < 10% canopy cover), and there can be remnant trees (trees remaining from the previous stand) that can provide <10% canopy cover.

3) Shrub/Seedling - Open
Seedlings are large enough to add structure to the stand but are small enough that the structure is similar to shrubs and may have remnant trees (trees remaining from the previous stand) that can provide <10% canopy cover. There is <70% cover of shrubs or seedlings. Tree size has <1" dbh, and there is only a single canopy stratum.

4) Shrub/Seedling - Closed
Seedlings are large enough to add structure to the stand but are small enough that the structure is similar to shrubs. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is >70% cover of shrubs or seedlings. Tree size has <1" dbh, and there is only a single canopy stratum.

5) Sapling/Pole - Open
The canopy is open enough that understory vegetation may be abundant. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is 10-39% cover of sapling and pole sized trees. Tree size is 1"-9" dbh, and there is a single canopy stratum.

6) Sapling/Pole - Moderate
Understory development is hampered by available light and moisture. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is 40-69% cover of sapling and pole sized trees. Tree size is 1"-9" dbh, and there is a single canopy stratum.

7) Sapling/Pole - Closed
The understory is depauperate or absent. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is > 70% cover of sapling and pole sized trees. Tree size is 1"- 9" dbh and there is a single canopy stratum.

8) Small Tree - Single Story - Open
A grass/forb or shrub understory may be present. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is 10-39% cover of small trees, with <10% cover of other tree sizes. Tree size is 10-14" dbh, and there is a single canopy stratum.

9) Small Tree - Single Story - Moderate
Some grass/forb or shrub understory may be present. Remnant trees (green trees remaining from the previous stand) can provide <10% canopy cover. There is 40-69% cover of small trees with <10% cover of other sized trees. Tree size is 10-14" dbh, and there is a single canopy stratum.

10) Small Tree - Single Story - Closed
Grass/Forb or shrub understory minor or absent. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is > 70% cover of small trees, with <10% cover of other sized trees. Tree size is 10-14" dbh, and there is a single canopy stratum.

11) Medium Tree - Single Story - Open
A grass/forb or shrub understory may be present. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is 10-39% cover of medium trees, with <10% cover of other sized trees. Tree size is 15-19" dbh, and there is a single canopy stratum.

12) Medium Tree - Single Story - Moderate
Grass/Forb or shrub understory may be present. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is 40-69% cover of medium trees with <10% cover of other sized trees. Tree size is 15-19" dbh, and there is a single canopy stratum.

13) Medium Tree - Single Story - Closed
A grass/forb or shrub understory may be present. Remnant trees (trees remaining from the previous stand) can provide <10% canopy cover. There is >70% cover of medium trees with <10% cover of other sized trees. Tree size is 15-19" dbh, and there is a single canopy stratum.

17) Small Tree - Multi-story - Open
These stands have an overstory of small trees with a distinct subcanopy of saplings and/or poles. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb or shrub understory may be present. There is 10-39% total canopy cover dominated by small trees, at least 10% or more canopy cover of 1 or more other smaller tree sizes. Tree size is 10"-14" dbh, and there are two or more canopy strata.

18) Small Tree - Multi-story - Moderate
These stands have an overstory of small trees with a distinct subcanopy of saplings and/or poles. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb or shrub understory may be present, but is probably limited. There is 40-69% total canopy cover dominated by small trees, at least 10% or more canopy cover of 1 or more other smaller tree sizes. Tree size is 10"-14" dbh, and there are two or more canopy strata.

19) Small Tree - Multi-story - Closed
These stands have an overstory of small trees with a distinct subcanopy of saplings and/or poles. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb or shrub understory extremely limited or absent. There is >70% total canopy cover dominated by small trees, at least 10% or more canopy cover of 1 or more other smaller tree sizes. Tree size is 10-14" dbh, and there are two or more canopy strata.

14) Large Tree - Single Story - Open
Grasses, shrubs, and/or seedlings may occur in the understory. There is 10-39% cover of large and/or giant size trees with <10% cover of other sized trees. Tree size is 20"-29" dbh, and there is a single canopy stratum.

15) Large Tree - Single Story - Moderate
Some grass/forb or shrub understory may be present. There is 40-69% cover of large and/or giant trees with <10% cover of other sized trees. Tree size is 20"-29" dbh, and there is a single canopy stratum.

16) Large Tree - Single Story - Closed
Grasses, shrubs, and/or seedlings may occur in the understory. There is >70% cover of large and/or giant trees with <10% cover of other sized trees. Tree size is 20"-29" dbh, and there is a single canopy stratum.

20) Medium Tree - Multi-story- Open
These stands have an overstory of medium trees with a distinct subcanopy of smaller trees. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb or shrub understory may be present, but is probably limited. There is 10-39% total canopy cover dominated by medium trees, at least 10% or more canopy cover of 1 or more smaller tree sizes. Tree size is 15"-19" dbh, and there are two or more canopy strata.

21) Medium Tree - Multi-story - Moderate
These stands have an overstory of medium trees with a distinct subcanopy of smaller trees. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb or shrub understory may be present, but is probably limited. There is 40-69% total canopy cover dominated by medium trees, at least 10% or more canopy cover of 1 or more smaller tree sizes. Tree size is 15"-19" dbh, and there are two or more canopy strata.

22) Medium Tree - Multi-story - Closed
These stands have an overstory of medium trees with a distinct subcanopy of smaller trees. Scattered larger trees may be present but make up less than 10% canopy cover. Grass/forb understory may be present, but is probably limited. There is >70% total canopy cover dominated by medium trees, at least 10% or more canopy cover of 1 or more smaller tree sizes. Tree size is 15"- 19" dbh, and there are two or more canopy strata.

23) Large Tree - Multi-story - Open
These stands have an overstory of large or giant sized trees with one or more distinct canopy layers of smaller trees. Stands > 40% cover of giant trees are classified in the "Giant, multi-storied" stage. In westside forests, stands dominated by large trees, usually have giant trees scattered in the stand, with lower numbers in eastside forests. Grass/Forb or shrub understory often present, especially in canopy gaps. There is 10-39 % total canopy cover, with at least 10% or more canopy cover from large and/or giant trees and another 10% or more canopy cover from 1 or more smaller tree size classes. Tree size is 20"-29" dbh, and there are two or more canopy strata.

24) Large Tree - Multi-story - Moderate
These stands have an overstory of large or giant sized trees with one or more distinct canopy layers of smaller trees. Stands > 40% cover of giant trees are classified in the "Giant, multi-storied" stage. In westside forests, stands dominated by large trees, usually have giant trees scattered in the stand, with lower numbers in eastside forests. Grass/Forb or shrub understory often present, especially in canopy gaps. There is 40-69% total canopy cover, at least 10% or more canopy cover from large trees with another 10% or more canopy cover from 1 or more smaller tree size classes. Tree size is 20"-29" dbh, and there are two or more canopy strata.

25) Large Tree - Multi-story - Closed
These stands have an overstory of large or giant sized trees with one or more distinct canopy layers of smaller trees. Stands > 40% cover of giant trees are classified in the "Giant, multi-storied" stage. In westside forests, stands dominated by large trees, usually have giant trees scattered in the stand, with lower numbers in eastside forests. Grass/Forb or shrub understory often present, especially in canopy gaps. There is >70% total canopy cover, at least 10% or more canopy cover from large trees with another 10% or more canopy cover from 1 or more smaller tree size classes. Tree size is 20"- 29" dbh, and there are two or more canopy strata.

26) Giant Tree - Multi-story
These stands have an overstory of giant sized trees with one or more distinct canopy layers of smaller trees. Stands with <40% canopy cover are classified in the "large tree - multi-story - open", stage. There is > 40% canopy cover. Tree size is > 30" dbh, and there are two or more canopy strata.