Chapter 1 - Núria BONADA

Annex 2. Chemical ranges from several variables from Prat et al. (2001).
IBMWP
100 Very good water quality
QBR
?25 Extreme dregadation, very poor quality
30-50 Strong alteration, poor quality
55-70 Considerable disturbance, fair quality
75-90 Some disturbance, good quality
?95 Riparian habitat in natural condition
AMMONIUM (mg/l)
4 Very poor water quality, with high toxicity
N-NITRITES (mg/l)
0.3 Very Poor water quality, with high toxicity
P-PHOSPHATES (mg/l)
0.5 Very poor water quality and very high eutrophy
SULPHATES (mg/l)
1000 Very Poor water quality
CHLORIDE (mg/l)
1000 Very poor water quality, saline
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Local scale: Optimums and tolerances in Trichoptera