EVS 1101 Lecture Notes - Lecture 17: Overexploitation, Silt, Soil Fertility

• School: University of Ottawa
• Department: Environmental Science
• Course: EVS 1101
• Professor: Danielle Fortin

Document Summary

1 cm of topsoil takes millions of years to form. Soil consists of mineral matter, organic matter, air and water. Dead and living microorganisms and decaying materials; bacteria, algae, earthworms, insects, mammals, amphibians and reptiles are also found in soil. Some of the most fragile regions are in the arctic with very low soil production, very slow turnover of organic matter. Parent material= base geological material of soil (lava, volcanic ash, rock, dunes) Bedrock= the continuous mass of solid rock comprising the earth"s crust. Weathering= the physical (mechanical; wind and rain, no chemical changes in parent material), chemical (substances chemically interact with parent materials) and biological (organisms break down parent material) processes that break down rocks to form soil. Lichen are pioneer species initiating primary succession by creating micro fractures in the soil, this enables the water to get in and with warm and cool cycles it grows, acids also help to degrade the bedrock.