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Soil. Soil quality - based on properties Observed: soil profile, composition, texture, or particle size Measured: pH and permeability. Soil Profile. Soil forms in layers - soil profile Litter – organic matter on top Topsoil- nutrient rich top layer, for plant growth
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Soil Soil quality - based on properties • Observed: soil profile, composition, texture, or particle size • Measured: pH and permeability
Soil Profile • Soil forms in layers - soil profile • Litter – organic matter on top • Topsoil- nutrient rich top layer, for plant growth • Subsoil- under topsoil, small rocks • Bedrock- semi solid rock
Composition rock particles, minerals, decayed material, air & water • combination of these affects • type of plants • type of animals
Texture & particle size • Texture - size of individual soil particles. • Determined by: proportions of sizes that make up soil • Particle size range – tiny (clay) to > 2 mm (gravel)
Permeability • open spaces allowing water to flow through it. • How freely water flows is called permeability. • Used to understand drainage • Percolation: amt of seepage
pH • Soil can be acid-like or base-like depending on measure of pH • Soil pH range is 4-10 with lower numbers being acidic • Healthy soil is between 5-7
Soil • MVP = most important abiotic factor in an ecosystem because everything that lives on land depends directly or indirectly • We lose 7% of topsoil / decade, = more desert-like conditions. • As a result of this, Ecosystems are changing.