Tomahawk Lake

Vegetation History

During the time period of approximately 1200-670 cal. yr BP, Tomahawk Lake can be characterized by jack-red pine (Pinus banksiana-Pinus resinosa) pollen. Alder (Alnus spp.) was also relatively high during this period. Jack-red pine decreased slightly at the end of the period when white pine (Pinus strobus) and birch (Betula spp) increased in the area. Between 670-80 cal. yr BP, both types of pine pollen stayed relatively high at about 30%, although the abundance of white pine peaked around 670 cal. yr BP. This period is classified as pine-oak (Pinus-Quercus), with a brief switch to jack-red pine at 300 cal. yr BP. European settlement increased the ragweed (Ambrosia spp.) and other non-arboreal pollen percentages as well as jack-red pine and white pine decreased.

Fire History

Tomahawk Lake is similar to Ferry and Hellhole Lake. Charcoal was lowest at 1050-650 cal. yr BP, a period that jack pine and then jack-red pine vegetation dominated. More recent than 650 cal. yr BP, white pollen increased as influx rates of charcoal also increased slightly. Both total and grass charcoal influx peak between 450-250 cal. yr BP. Like Ferry Lake and Sawdust Lake, the charcoal records from Tomahawk Lake were dominated by the low-influx, low-frequency charcoal signature types including periods with larger peaks before 700 cal. yr BP. Although at Tomahawk Lake, charcoal signatures changed at approximately 1300 cal. yr BP with an average fire return interval of 85 years. Low values of background CHAR were also observed in the cores from Tomahawk Lake.