ENVR 200 Lecture 11: Soil, Groundwater, and Nutrients Flashcards

Vocabulary flashcards covering the components of the lithosphere, soil formation and properties, nutrient dynamics, eutrophication, and groundwater zones based on Lecture 11.

Lithosphere

The topmost layer of the rock surface of the planet, consisting of solid rock about $60\,\text{km}$ deep, which also contains water and gases.

Parent Rock

The original rock type that undergoes breakdown (weathering) over time to form soils, dictating the physical and chemical properties of the resulting soil.

Organic Matter

Structures of biological origin that enter soil through the decomposition of dead organisms, concentrating primarily in the top, biologically active layers.

Sand

Soil mineral particles with the largest size ($0.05\,\text{mm}$ to $2.0\,\text{mm}$), creating large spaces between particles that allow water to pass through rapidly.

Silt

Soil mineral particles with intermediate size ($0.002\,\text{mm}$ to $0.05\,\text{mm}$), positioned between sand and clay in particle size.

Clay

Soil mineral particles with the smallest size ($< 0.002\,\text{mm}$), offering a large surface area that holds water and positively charged nutrients effectively.

Eutrophication

The process where high inputs of nutrients, such as phosphorus, enter a body of water and trigger an explosive overgrowth of algae.

Dead Zones

Areas in aquatic environments where microbial oxygen consumption during algal decomposition lowers dissolved oxygen levels, causing aquatic animals to suffocate.

Soil-water Zone

The upper layer of soil closest to the surface where plant roots and animals reside, containing abundant pore space and water bound tightly to soil particles.

Unsaturated Zone

The subsurface region below the soil-water zone through which water moves downward under gravity toward the water table, harboring minimal biological activity besides microbes.

Saturated Zone

The subterranean area below the water table where all pore spaces between soil particles and rock openings are entirely filled with water.

Water Table

The upper boundary level of the saturated zone, separating it from the unsaturated zone above.

Groundwater

Water located in the saturated zone beneath the Earth's surface that completely fills all spaces between soil particles and fractured rock.

Hydrophobic Soil

Extremely dry soil that temporarily repels water due to polar phospholipids from dying microbes binding their hydrophilic heads to soil particles while hydrophobic tails point outward.

Atoll

A ring-shaped coral reef or island enclosing a lagoon, formed as weathering and subsidence submerge a former volcanic island after volcanic activity ceases.