Geography 2152F/G Lecture 11: Wildfires
22 Apr 2016
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Document Summary
After a fire, vegetation completes a cycle from early colonizing plants to mature ecosystem. Ecosystem that evolves adapts to the climate at that time and location. Many species can withstand fire or promote the life of the species after a fire. Some pine trees have seeds that only open after a fire. Increase in amount of charcoal in sediment approx. 10,000 years ago: due to warmer and/or drier climate, due to increased use of fire by humans. Plants accumulate carbon dioxide and store carbon in their tissues. During a wildfire, carbon dioxide released into atmosphere. Pre-heating: vegetation reaches a temperature at which it can ignite, as heated, vegetation loses water, can take many weeks. Pyrolysis: chemical process describing the degradation of large hydrocarbon molecules into smaller ones, process occurs in the presence of heat i. e. from the heat of nearby fire. Ignition: can occur repeatedly as fire moves, not all ignitions will result in wildfire (vegetation must be dry)
