GEOG 1350 Lecture Notes - Lecture 11: Canadian Shield, Pinus Contorta, Northern Hemisphere
22 Apr 2018
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Document Summary
Wildfire dates to the time when trees first evolved 400 million years ago. Many fires start naturally as a result of lightning or volcanic eruptions. After a fire, vegetation completes a cycle from early colonizing plants to mature ecosystem. The ecosystem that evolves adapts to the climate at that particular location and time. Many species have evolved to withstand fire or promote the life of the species after a fire event. Examples: oak and redwood trees have bark that resists fire damage, some pine trees have seeds that only open after a fire. The geologic record shows an increase in the amount of charcoal in sediment approximately. This suggests high amounts of wildfire activity at the time. Why might there be more fire activity: a warmer and/or drier climate. Increased use of fire by humans for clearing land and for heat, cooking, etc. Wildfire requires three elements: fuel, oxygen, and heat.
