Chapter 15 Flashcards
Green Wall of China
300 million trees planted to keep out the dust storms of the Gobi desert
Soil
Weathering Process
The material is slowly broken down and fragmented into smaller and smaller pieces, such as rock to soil. Can take a veeeeeery long time.
Organisms play role in breaking down material
Soil Forming Factors
Weathering
Soil organisms respire and form CO2; it diffuses into the soil and mixes with soil water to become carbonic acid. Lichens also produce acids
Topography
a region’s surface features
i.e. presence of valleys, or mountains
Soil Composition
45% mineral particles
5% organic matter
25% water
25% air
organisms reacts in soil-> some die, decompose, fertilize soil
Humus
mix of organic compunds
binds to nutrient material ions, holds water
Detritivores break down humus
soil water
water in soil
rain fills pore space
soil air
air in soil
water drains, pulls air into pore space
Leaches
percolates, moves down through soil layers
Illuviation
deposition of leached material in lower layers of soil
Soil Horizons
Horizontal organization of soil from the organic surface, to the underlying parent material, bedrock
O-Horizon
rich in organic material
plant litter accumulates, is decomposed
sometimes, O is absent, but sometimes it is dominent
Soil Profile
Vertical section of soil showing the horizons from the surface to the plant material
A-Horizon
topsoil, dark, rich, organic accumulation, humus
nutrient deprived from leaching