Finns det samband mellan brunifieringen av våra vatten och skogsbeståndet? / Is there a connection between brownification and standing volume of wood?
Brownification of water makes it harder to produce a high quality tap water. The humic content gives water a foul taste and fertilizes bacteria in the pipes. Most people are unanimous in that the brown colour in the surface water originates in the forest. But there are several understandings as to the reason why the content of humus has increased, such as decreased sulphur deposition and increased runoff. We have examined the hypothesis that it is simply the correlation, that more trees produce more humic acids, that is the essential cause, and variations in flow and sulphur deposition has resulted in variations in the increase. We have compared the change (increase) in standing volume of wood from the 1950’s to present day with the colour value in a number of major watercourses where long data series are available, and the overall picture is distinct; the coniferous woodland areas and the colour value has increased most in southern Sweden while the north parts have seen less increase in both variables.