In the autumn, leaves fall onto the ground, into the small ponds forming here and there, soon with brownish amber-coloured water. Resting for a moment on the surface, until a splash or a footstep causes it to cross the surface and sink towards the bottom, contributing to the forming colour.
As the leaves break down, the oxygen in the water is consumed, and the humus acids tint the pond. The water in the lower layers becomes reductive, oxygen deficit. Slowly the water sinks down, and enters the groundwater cycle.
What could these two things, the resting leaf and the amber-coloured water tell us about water quality? Continue reading