APES Unit 4

AP Environmental Science Unit 4: Earth Systems and Resources

How is soil formed from parent material (3)

• Weathering

• Transportation

• Deposition

Describe the process of weathering

Weathering is the physical breakdown of rocks into smaller material that could be done physically (wind and rain), Biologically( tree growing into cracks), or chemically (acid rain).

Describe the process of erosion

Erosion is the transportation of weathered small rocks through Wind and rain.

Deposition

Last step of erosion in which the small rock fragments and left at an area.

3 parent materials of soil

• Sand

• Silt

• Clay

Soil component factors determined by parent material

• ph level

• nutrient content

Soil Horizons

The different layers of soil

O-Horizon

Top, shallow layer of organic material that provides nutrients and traps water from being evaporated.

A-Horizon;/ topsoil

Layer of Hummus, decomposed organic matter, from O where most breaking down of organic matter happens

B-Horizon/ sub-soil

layer under A mostly made of minerals usually clay with little hummus

C-Horizon/bedrock

Parent material.

Soil degradation

The loss of ability for a soil to support plant growth

Consequences of loss of topsoil (2)

• Loss of organic matter found in the topsoil

• Loss of vegetation causes the soil to be more prone to erosion

Problems with dry soil

• Dry soil erodes more easily

• Dry soil supports less plant growth

Nutrient depletion of soil

As crops grow in soil they take away some of the nutrients such a nitrogen and phosphorus.

How does protecting soil boost water quality

Soil naturally filters water that moves through it.

How does particle size of soil influence how well air and water passes through

• Because sand has a bigger particle size water and air can pass through easily

• Because clay has a smaller particle size it is harder for air and water to pass through

Porosity

The amount of pore space a soil has (sand has a high porosity and clay has a low porosity)

Permeability

How easily water passes through a soil

Explain why soil that is too permeable is bad for plant growth

Soil with particle sizes that are too big allow water to pass through too quickly and never reach the roots. This means that the plants are left wit insufficient nutrients and water in order to thrive.

Explain why soil that has a low porosity is bad for plant growth

When there is small pore space, the soil can get waterlogged and air have trouble moving through the soil which limits cellular respiration for plants. This negatively impacts the plant’s ability to absorb nutrients and grow.

Most ideal soil for plant growth.

• Loam

• PH between 6 - 7.5

• Darker soil

Tests for soil quality and what they tell you(5)

• Texture - The percent of sand soil or clay

• Permeability -How easily water passes through the soil

• PH - how acidic the soil is, the more acidic a soil is the less nutrient availability

• Color- Darker soil indicates more hummus

• Nutrient level- Higher nutrient levels are better for plant growth

Convergent Boundaries and effects (4)

Plates move toward eachother causing subduction which can lead to:

• Mountains

• Earthquakes

• Volcanoes

• Island arcs

Divergent boundary and effects (5)

Plate move away from each other due to rising mantle which leads to:

• Sea floor spreading

• rift valleys (land)

• Mid-Oceanic ridges ( causing mountain ranges underwater)

• Volcanoes

• earthquakes

Transform boundaries and its effects

Plates slip past each other causing earthquakes

gasses of earth’s atmosphere and percentages

• Nitrogen (78%)

• Oxygen (21%)

• Argon (0.93%)

• Water vapor (0-4%)

• Carbon dioxide (0.04%)

Troposphere

becAtmosphere layer closest to earth’s surface 0-16km.

• Densest layer that houses the most gasses

• Ozone in this layer is harmful to plants and humans’respiration

• Temperate decreases with increasing altitude because earth's surface is heated by the sun

Stratosphere

Second closets layer to earth 16-60km

• Thickest layer of Ozone that abosorbs UV rays that can cause cancer in animals

• Temperature increases with altitude

Mesosphere

Third closest layer in the middle that is even less dense than the closest 2

• Temperature decreases as altitude increases

Thermosphere

4th closest layer to the earth with the hottest layers

Exosphere

Outermost layer that merges with earth.