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

Soil

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.