Identification of Fine-Scale Marine Benthic Ecoclines by Multiple Parallel Ordination
Table 1
Sampling of sites based on stratified random sampling of geomorphological features. The classification into geomorphological features was based on a slightly modified version of an algorithm by Lundblad et al. [23], which takes into account fine- and broad-scaled geomorphological variation.
Geomorphology
Cover (%)
Sites
BPI65
BPI33
Slope65
Slope33
Depth
Fine-scaled features
Narrow depression
6.4
1-2, 26
≤−1 SD
≤–1 SD
Broad depression with open bottom
3.2
3-4
≤−1 SD
w/in 1 SD
Narrow crest
7.6
5-6, 25
≥1 SD
≥1 SD
Local depression on flat
0.1
7
w/in 1 SD
≤–1 SD
≤5
Lateral midslope depression
1.4
8-9
w/in 1 SD
≤–1 SD
>5
Local crest on flat
0.1
10
w/in 1 SD
≥1 SD
≤5
Lateral midslope crest
1.2
11-12
w/in 1 SD
≥1 SD
>5
Shallow flat
28.4
13–15, 27
>−1 SD
w/in 1 SD
≤5
≤58.6
Deep flat
15.7
16–18
>−1 SD
w/in 1 SD
≤5
>58.6
Shallow slope
21.9
19–21, 28
>−1 SD
w/in 1 SD
>5 and ≤70
≤58.6
Deep slope
14.0
22–24
>−1 SD
w/in 1 SD
>5 and ≤70
>58.6
Total
100.0
Broad-scaled features
Depression
9.6
1–4, 26
≤−1 SD
Crest
11.1
5-6, 25
≥1 SD
Deep flat
16.1
7, 11, 16–18
w/in 1 SD
≤5
>58.6
Shallow slope
19.6
8-9, 19–21, 28
w/in 1 SD
>5
≤58.6
Shallow flat
29.4
10, 13–15, 27
w/in 1 SD
≤5
≤58.6
Deep slope
14.2
12, 22–24
w/in 1 SD
>5
>58.6
Total
100.0
Cover: estimated percentage of the study area covered by the feature; Sites: number of the sampled sites belonging to each fine- and broad-scaled feature class; BPI65 and BPI33: bathymetric position index rasters calculated from 65 and 33 m moving windows; Slope65 and Slope33: corresponding rasters for slope. The mean depth of the study, 58.6 m, was used to differentiate between shallow or deep slopes and flats, respectively.
