Chemical Conditions in Ösbysjön, Djursholm. I. Factors Related to Organic Production

Abstract

An investigation of Lake Osbysjon, a seepage lake situated 9 Ian north of Stockholm, was carried out during the years 1957-1961. Different aspects of the water chemistry are treated in relation to the capacity of organic production of the lake. The water temperature of the ice-free season largely follows the changes in the maximum of the air temperature. Respiratory processes are predominant in the lake. The yearly average degree of O2 saturation was about 60%. During the winter the entire lake can be completely O2-free for some time. PO4-P is low in the lake and the total P is lower than in several Uppland lakes investigated by Lohammar (1938). The phosphate released during the periods of stratification from the sediment is rapidly taken up by the living organisms. NO3-N is low during the ice-free season. At the end of the winter stratification comparatively high values of NO3-N occur in the upper water ayers. The variations In silica concentration are governed by several factors. In the bottom water silica and CO2 show a similarity in development with time.