Chapter 4: Terrestrial Environment Flashcards
How do you calculate leaf area index?
Area of leaf over ground area
How much light reaches the forest floor?
1-5%
Pigment that allows plant to detect shading
There are increased amounts in shaded plants
Phytochrome
Why is soil important?
Medium for plant growth
Controls water levels
Decomposition and recycling
Important habitat
Unconsolidated mineral and organic maggot over unweathered rock
Soil
Destruction of rock material into smaller particles
Weathering
What are types of weathering?
Mechanical
Chemical
How is soil formed?
Parent material Biotic factors Climate Topography Time
Type of soil formation
Undifferentiated material from which soil develops
Parent material
Type of soil formation including the decomposition of organic matter and the ability of plant roots to hold soil in place
Biotic factors
Type of soil formation
Temperature, precipitation, and wind
Maximized at warm and wet conditions
Climate
Type of soil formation
Sloped causes more erosion
Soil affected by exposure to solar radiation and wind
Topography
Type of soil formation
Well devolved soil between 2,000 and 20,000
Time
Name the horizons from surface to deep
Organic Topsoil Subsoil Rock fragments Bedrock
To wash out (in soil horizons)
In the E horizon of the topsoil
Elluviation
To wash in; deposits (soil horizons)
In the subsoil
Illuviation
Type of soil formation process Humid environments Heavy leaching of nutrients Characterized by iron oxides Acidic soils
Laterization
Type of soil formation Water loss exceeds precipitation Water taken up by plants Calcium carbonates build up Deposition and build up of alkaline salts in subsoil B horizon looks white from calcium
Calcification
Type of soil formation process
Dry climates and coastal regions from salt spray
Salt deposits near surface
Salinitization
Type of soil formation
Coolly, moist climate
Acidic soil enhances leaching of cations (Fe & Al) from topsoil
Spodosols formed
Podzolization
Type of soil formation process High rainfall or poor drainage Slow decomposition of organic matter Accumulates in upper layers Gleisol formed
Gleization
More water than the pore space can hold and excess water drains freely from the soil
Saturated
If water fills all of the pore spaces and is held there by capillary forces
Field capacity
Water held between soil particles by capillary forces
Capillary water
The amount of water retained by the soil between field capacity and wilting point
Available water capacity
The total number of negatively charged sites, located on the edge of clay particles and soil organic matter
Negatively charges enable a soil to prevent leaching of positively charged nutrient cations
Cation exchange capacity
What are the five soil formation processes?
Calcification Laterization Salinization Podzolization Gleization
