2.2. Physicochemical analyses
Ammonium, nitrate, nitrite, and phosphate transport were measured by
flow (injection) colorimetric analysis using a computer-controlled FOSS
FIAStar 5000 apparatus. The NH4+,
NO2-,
NO3-, and
PO43- concentrations were determined
using a spectrophotometer and recalculated as
N-NH4+,
N-NO2-,
N-NO3-, and
P-PO43-. Samples from the mountain
streams were collected monthly using the bathymetric method (containers
with a volume of 1 dm3). The concentration of the TSS
was determined by the gravimetric method (after drying) using tarred
filters (with an accuracy of ± 0.0005 g). The dry residue (sum of
mineral particles from the transported samples) from the collected
material was filtered to determine the concentration. The total number
of water samples was 140, collected over five years from April to
November each year.