Prehistoric pH Trends in Kejimkujik Lake, Nova Scotia

✍ Scribed by L. Denis Delorme; Sylvia R. Esterby; Hamish Duthie

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 724 KB
• Volume: 69
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.19840690105

✦ Synopsis

A h t rac t

Kejimkujik Lake in Nova Scotia has an average p H of 4.8 and rcceives wet precipitation with a weighted mean pH of 4.62. The lake is situated in a drainage basin where organic rich soils and bogs rest upon poorly buffered igneous and metamorphic rocks. Fossil diatoms from a sediment core reveal that since 21.7 em the pH trend has been to a lower pH. The flora of the lake between 13.0 and 10.7 em indicate a climatic change to a dryer period followed by a return to a more moist and humid climate. Colonization by European settlers,around 1850 A D . drastically altered the pH of Kejimkujik Lake through deforestation and burning of lumbering refuse. The effect, of pot.assium hydroxide, by leaching potassium from wood ash, on the lake continued to 2.2 cm (about 1950) when the acidit.y began t.0 drop to lower more normal levels. The overriding effect on the lake a.ppears t.o have been the presence of organic soilsa.nd bogsmhich have contributed organic acids to the system since a t least 21.7 m i .