Hydrochemical Variations in Spruce, Beech and Grassland Areas, Mont Lozere, Southern France

1991

S. 57-70

5 Abb., 3 Tab., 23 Lit. Ang.

Unselbständiges Werk

200088122

Eight years of hydrochemical data are presented for streams draining beech forest, grassland and spruce forest catchments in the Mont Lozere region. The mean concentration of cations in the streams occurs in the order: beech forest < grassland < spruce forest. The broad changes in stream chemistry follow a synchronous pattern related to variations in climatic conditions. Stream chemistry varies only to a moderate degree with flow, though in fine detail concentration fluctuations are very complex during storm events; hysteresis is observed. Estimations of pCO2 levels from the pH and alkalinity data show a wide scatter: the levels seem to be about five times the atmospheric value for all the streams. It is concluded that these catchments are still in an early stage of acidification. The spruce forest catchment acidifies faster than the woodland and the grassland catchments. Uncertainty remains as to the importance of air scavenging processes.