Chapter 1 - Núria BONADA

Regional amd local scale: convergences and divergences
Reference sites in Med-Basin have a higher pH and IHF compare with SWAustralia and South
Africa, but a lower riparian quality. Californian sites are located near Med-Basin with more
neutral pH but variable conditions of riparian vegetation and habitat diversity. Finally,
samples from South Africa and SWAustralia are associated with low pH, high temperature,
good riparian quality and medium to lower habitat diversity.
3
2
1
0
-1
-2
-3
X 1 =39.70%
X 2 =29.04%
Temperature
QBR
IHF
-3 -2 -1 0 1 2 3
MedBasin
California
SWAustralia
South Africa
Figure 5. PCA plot with environmental variables in reference sites.
pH
Correlations X1 axis X2 axis
pH 0.5891 -0.3827
Temperature -0.6315 -0.1518
QBR -0.0686 0.8313
IHF 0.4995 0.3735
Relative abundance of common taxa between sampled med-regions
In Table 4, results of the non-parametric ANOVA (model Kruskal-Wallis by ranks) indicate that
in permanent sites, the relative abundance of taxa is variable between med-regions, with a
51% of common taxa showing significative differences in abundance between regions (p-
value