Figure 1.
Location of the sampling sites.
The elevation and the main river basins are also shown (a - Minho; b - Lima; c - Cávado; d - Ave; e - Douro; f - Vouga; g - Mondego; h - Lis; i - Extremadura coastal basins; j - Tagus; k - Sado; l - Mira; m - Algarve costal basins; n - Guadiana).
Table 1.
Median and range of environmental variables measured at 117 least disturbed sites in Portugal.
Table 2.
Catch (median and 1st-3rd quartiles; individuals per 1000m2), frequency of occurrence (FO) (%), index of relative dominance (IRD), and functional guilds for fish taxonomic groups collected in Portugal.
Table 3.
Loadings of regional and local variables on the first two principal components (PC) extracted by PCA and the eigenvalues and proportions of variance accounted for by each axis for the 117 sites in Portugal.
Figure 2.
Relative importance of each variable given by the probability of the variable to be included in the best models as measured by the Akaike weights.
The relative importance of each variable corresponds to the sum of its weight with the weight of its quadratic term with a maximum value of 1. Metrics abbreviations as follows: NOTO - density of non-tolerant individuals, TOLE - density of tolerant individuals, INVE - density of invertivores individuals, OMNI - density of omnivorous individuals, BENT - density of benthic individuals, WACO - density of water column individuals, LITH - density of lithophilic individuals, POLY - density of polyphilic individuals, POTA - density of potamodromous individuals, NATI - number of native species, DENS - total density of native individuals.
Table 4.
Summary results of model selection for the relations between fish metrics and environmental gradients reflected in each of the two components extracted from principal component analyses of regional (R) and local (L) variables.