Identification of Fine-Scale Marine Benthic Ecoclines by Multiple Parallel Ordination

Table 5

Kendall's 𝜏 correlations between environmental variables and DCA axes 1 and 2 with no (𝑅₁), intermediate (𝑅₃₂), and strong (𝑅_max) weight given to abundance.

Variable/range	DCA1			DCA2
	𝑅1 (qual)	𝑅32	𝑅max (raw)	𝑅1 (qual)	𝑅32	𝑅max (raw)
DEM derived
Aspect_E	0.011	−0.026	−0.090	0.148	0.021	0.196
Aspect_N	0.101	0.032	−0.074	−0.069	−0.143	−0.085
BPI	0.228	0.169	0.148	−0.016	−0.164	−0.201
Depth	−0.656	−0.820	−0.757	−0.053	−0.063	0.079
Seabed_curv	0.169	0.132	0.079	−0.127	−0.169	−0.312
Slope	0.127	−0.005	−0.153	−0.148	−0.021	−0.132
Current model
Current_bottom	−0.026	−0.095	−0.085	−0.037	−0.143	0.085
Current_surface	−0.307	−0.407	−0.471	−0.212	−0.106	−0.090
Change_curr_bottom	0.074	0.101	0.132	−0.032	−0.053	−0.005
Change_curr_surface	−0.058	−0.138	−0.116	0.090	0.143	0.254
Direction_curr_E	0.024	−0.024	−0.083	−0.008	−0.110	−0.143
Direction_curr_N	0.179	0.094	0.083	−0.035	−0.265	−0.099
Sediment features
Mud content	0.053	0.122	0.069	−0.116	0.095	0.164
Sed_kurt	0.240	0.272	0.245	−0.191	−0.046	−0.073
Sed_med	−0.027	−0.074	−0.095	0.090	0.000	−0.032
Sed_skew	0.099	0.184	0.152	−0.056	0.088	0.318
Sed_sort	0.130	0.135	0.114	0.227	0.146	0.205
Other variables
BMD	−0.412	−0.434	−0.445	0.233	0.228	0.385
Penetration_depth	−0.174	−0.227	−0.286	0.184	0.067	0.206
CN	0.265	0.286	0.318	−0.170	−0.202	−0.260
TOC	−0.202	−0.303	−0.330	−0.245	−0.250	−0.106
TN	−0.257	−0.349	−0.393	−0.149	−0.149	0.008
VEAS_dist	0.349	0.407	0.407	0.138	−0.021	−0.122

Bold values represent |𝜏| ≥ 0.225, which corresponds to a P value of approximately 0.10 in test of the hypothesis that 𝜏=0 when 𝑛=28. The unconfirmed second axis (DCA2.𝑅₁) according to criteria given in Section 2.6 is shown in italic.