Spatial variability, structure and composition of crustose algal communities in Diadema africanum barrens

Table 3 Results of DistLM (distance-based linear model routine) considering species cover

Variable	Pseudo-F	p	% var.
(A) Marginal test
Urchin density	6.297	0.0002	7.06
Wave exposure	28.378	0.0001	15.38
Productivity	26.30	0.0001	14.22
Depth	3.147	0.014	2.59
Substrate roughness	7.495	0.0001	7.97

Variable	Pseudo-F	p	% var.	Com. % var.
(B) Sequencial test
Wave exposure	30.152	0.0001	15.17	15.17
Urchin density	9.353	0.0001	7.11	22.28
Substrate roughness	8.574	0.0001	6.47	28.76
Productivity	6.633	0.0003	5.20	33.96
Depth	3.147	0.015	2.59	36.56

(A) Test for relationships between individual environmental variables and species cover. (B) Test for relationships between environmental variables and species cover considering all environmental variables integrated in a multiple regression model

ISSN: 1438-3888