Geography 2152F/G Lecture 11: Wildfires
21 Apr 2016
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Document Summary
Dates to the time when trees first evolved 350 mya. Many wildfires start naturally due to lightening 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 evolved to withstand fire or promote life of species after fire event. Oak and redwood trees have barks which resist fire damage. Some pine trees have seeds that only open after a fire. The geologic record shows an increase in amount of charcoal in sediment approximately 10,000 years ago. This suggests high amounts of wild fire activity at that time due to: Increased use of fire by humans for clearing-land, heat and cooking. Wildfire requires 3 elements: fuel, oxygen, and heat. Plants accumulate carbon dioxide and store carbon in their tissues. During wildfire, the co2 is released back into the atmosphere. Wildfire occurs in 3 phases: pre-ignition, combustion, extinction.
