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Download Fire Effects on Soil. What are the Functions of Soil within Ecosystems? Provides a medium for plant growth and supplies nutrients Regulates the hydrologic

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  • Slide 1
  • Fire Effects on Soil
  • Slide 2
  • What are the Functions of Soil within Ecosystems? Provides a medium for plant growth and supplies nutrients Regulates the hydrologic system, receiving, holding, and releasing water Recycles nutrients and organic wastes Habitat for living organisms and supports the detritus food chain How does fire alter these functions?
  • Slide 3
  • Changes in Soil Properties Changes in soil properties due to heat and temperature Physical properties Chemical properties Biological properties Variable effects depending on fire regime Frequency, timing, and intensity
  • Slide 4
  • Fire effects on soil properties is dependent on sensitivity to change Sensitivity is temperature dependent Relatively insensitive- exceed 460C Moderately sensitive- 100-400C Sensitive- less than 100C
  • Slide 5
  • Relatively Insensitive Soil Property Threshold temperature (C) Manganese1962 Calcium1484 Magnesium1107 Clay alteration460-980 Phosphorus774 Potassium774
  • Slide 6
  • Moderately Sensitive Soil Property Threshold temperature (C) Sulfur 375 Soil structure300 Soil wettability250 Nitrogen200 Organic matter100
  • Slide 7
  • Sensitive Soil Property Threshold temperature (C) Bacteria60-120 Fungi60-80 Plant roots48-54 Seeds70-90 Small Mammals49-63
  • Slide 8
  • Maximum ground surface temperatures within different ecosystems
  • Slide 9
  • Sensitivity and Soil Depth Most significant effects at the soil surface Peak temperature decreases rapidly with depth Soil temperature with depth is dependent on fire intensity and fuel load, including litter layer
  • Slide 10
  • Physical Effects: Removal of Plant Material by Fire Increases soil temperatures Loss of shading from vegetation Removal of insulating litter Altered albedo of soil surface Litter removal increases surface runoff and erosion potential
  • Slide 11
  • Physical Effects: soil organic matter Def. All organic carbon compounds in the soil, including plant and animal residues at various stages of decomposition Aggregation of mineral particles by OM forms the structure of surface horizons
  • Slide 12
  • Physical Effects: soil organic matter Combustible, volatile during fire Moderately sensitive, little lost at

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