Chapter 1 - Núria BONADA

Chapter 7
% of total variation
% of variation from environment
100
80
60
40
20
0
100
80
60
40
20
0
Non-explained (78%)
Seasonality (0.93%)
Environment+Seasonality (0.2%)
Environment (20.8%)
Temporality (2.3%)
Biological comunities (16.5%)
Physical-Chemical parameters (27.3%)
Geomorphology (53.9%)
Figure 9. Variance partition with trichoptera data. Top graph present the percentages of all variation
explained by environment and seasonality. Bottom graph present the total variation expressed by
environment, separated by geomorphology (basin, riparian and habitat characteristics), physical-chemical
variables, biological communities (IBMWP and IASPT) and temporality.
DISCUSSION
Observed patterns in caddisfly distribution in the Iberian Mediterranean area are spatial and
temporal heterogeneous. Consequently, our results agree with the idea that distribution areas
are dynamic structures (Antúnez & Mendoza, 1992), and they should be studied in a spatial-
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