Unit 4 Soils Quiz

Soil Physical Weathering

• Abiotic: water, wind, temp; Biotic: roots/burrowing

• Increases surface area

Soil Chemical Weathering; Acid Rain?

• Changes compounds - carbonation, oxidation, hydrolysis

• Releases nutrients, P cycle

From above v. below soil prod

• Below: Physical breakdown rocks = raw material

• Above: deposits dead organisms/waste

• Mature soils more org/nutrients; nutrient-ppor if leached by water

Plate Tech - Hot Spots

No boundary; where magma melt through Earth’s crust

Porosity v. Permeability

• porosity: space btwn particles (Sand big)

• permeability: speed water through (clay slow)

Soil Horizons:

• O (organic): organic matter decomp (humus)

• A: topsoil, first by rock; weathered, most bio activity

• Eluviated: some acidic; no org, metals/nutrients leached from above.

• B: subsoil; zone of accum minerals/nutrients

• C: parent material, least weathered

• R: bedrock

Properties Determined By

• Parent Material: nurtient poor/rich

• Climate: cold = no decomp, hot = weathering fast and leaching

• Topography: Erosion, depth soil, water over

• Organisms: Plants nutrients take, animals tunnel, cycles

• Time

• Humans: topsoil eroded, compaction = waterlogged, dry; less veg

Chemical Prop Soils/Biological

• CEC; cation exchange for nutrients, if acidic can’t hold

• Base Saturation: prop bases to acid, bases nutrients

• Bio: decomp (fungi, bacteria); detrivores (worms, rodents), N-fix

Watersheds Characters

• Area: volume from rain

• Length: principal flowpath

• Slope: runoff speed, erosion, wind

• Soil

• Vegetation: org matter, tree litter/roots stop erode, canopy cools water/rain+wind damage, riparian zone filter runoff

• Divides: Peaks and ridges

Types of Watersheds

• Agri: barren/compacted soil = less infiltration; fertilizer contam

• Urban: Lots runoff and floods; pollution into runoff

• Mountains: steep and rocks less porous; downstream flood

• Forest: evapotrans; high infil, low runoff

• Wetland: High rain/runoff, dom. evap

• Desert: porous; no rain/river, no refill groundwater

• Coastal: high rain, no control = flood and high water table, saltwater intrude

What can reduce water flow into a watershed, what will increase it?

• Reduce: restore wetlands to absorb, vegetation to retain

• Increase: Higher slopes; clear-cutting, compaction soil

Watershed clear-cutting?

• Water increase turbidity

• Less filtration by riparian