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APES
NDHS
Name: _______________________
Per: ________ Date: ____________
Land Formation and Uses
Land Formation
Layers of the Earth
Many geologists believe that as the Earth cooled the
and the
Four layers of the Earth:
1:
is made of the lightest materials
- consists of numerous plates with boundaries
Chemical makeup of the crust:
Oxygen
46.6%
Silicon
27.7
Aluminum
8.1
Iron
5.0
Calcium
3.6
Sodium
2.8
Potassium
2.6
Magnesium
2.1
All Others
1.5
2.
is much hotter and has the ability to
of flowing asphalt) 3&4.
– made of
Iron and Nickel (speculated)
(consistency
Geologic Processes:
Shifting of the Crust: Pg 110 and 111
- crust is broken up into
- location of the boundaries is the site of geologic activity such
as
(when the plates shift –
)
such as
Plate
boundaries:
1.
: move away from each other – create a ridge or trench
that may allow magma from the mantle to flow upward
2.
: plates ram into one another
- may push each other up and form mountains
- one plate may be forced
in a process called
– plate being forced under will eventually
the
through the crust of the overriding plate and
3.
: plates
 produce
of the shifting plates moving through the land
begins far below the surface at the focus which is
directly beneath the
– the point at the top of the
earth’s crust
– severity is measured on the
– each point on the scale is
than the point below it
Secondary effects of earthquakes
1.
2.
3.
property damage
deaths
landslides – massive erosion
4.
5.
tsunamis
pollution from destruction of property, etc
Volcano Formation:
1.
2.
3.
Types of Rock:
IMPORTANCE: type of rock  determines soil type
1.
– from the cooling of magma (lava)
Ex: obsidian, granite, pumice
2.
– form by the compaction of smaller
bits of eroded rock or deposited material
Ex limestone, diatomecious earth
3.
– rock that is changed because it is in
a new environment usually due to subduction – becomes
exposed to
and rearranges the
way the rock is organized
Ex:
Land Uses:
World Land Use:
%: Rock, ice, tundra, desert, roads, and urban areas
%: Forests
%:
Permanent Pastures
%: Cropland
%: Wetlands and Lakes
Uses of Land:
- living
- agriculture
- grazing
- logging
- preservation
- recreation
Managing Public and Private Lands in USA:
% is owned by the federal government
Overseen by:
______________________________
- Bureau of Land Management
- Fish and Wildlife Services
- National Park Services
______________________________
- U.S. Forest Service
Issues Of Land Use:
Overgrazing 
Over harvesting of timber 
Mining 
Tourism 
Land Management Techniques in US:
development can go where
: what types of
-
: changing areas can raise the taxes on that
land and thus prevent or encourage development
:
- prescribes what can and cannot be done in specific
areas
1.
: lands set aside to preserve their
primeval character and prevents permanent
improvements or human habitation
- these areas may be managed to prevent overuse issues
Ex: Build outhouse and camping sites to limit
damage done by people visiting the areas
2.
: Yellowstone – first NP
- preserve lands to teach people about the natural
environment, management of natural resources and
knowledge of national history
Problems:
3.
: to preserve lands and
waters for the conservation of fishes, wildlife, and
plants of the US
- allows for hunting, fishing and observation as long as
they fit with fish and wildlife management techniques
4.
: intended for multiple
uses – hunting, fishing, logging, water use, outdoor
recreation – all activities are regulated to maintain the
health of the area
Soil
Soil: More than just dirt
Components of Soil:
1)
- from
- Influences on Erosion:
–
– steep areas erode faster
crack rock
- determines the basic
of the soil
Ex: soil eroded from
will be
high in
and have a
Soil eroded from
will be higher in
or sodium and have a neutral or acidic pH
- can take
to produce
- depends on
- Fundamental unit is
- negative charge is occupied by
(
)
- determines
EX: Aluminum rich soils =
Magnesium and Iron Silicate soils =
- mineral content determines
of soil
- amount of
- Filled with
-
– air is necessary for the
in the soil
=
, does
of
large particles =
not hold water EX:
medium particles =
small particles =
holds water EX:
Size of particles
Soil texture is based on the amount of
=
– page 333
soil =
- water moving through soil by percolation is called
and is a solution of
- if soil is
minerals can leach
then the nutrients and
and the soil become
- leaching of nutrients into lower soil levels is called
2)
-
– return nutrients
to soil for plant uptake
- broken down by
(worms, insects such as beetle larva, beetles, ants,
termites)
- helps retain
- increases
- particularly beneficial for helping soils of low
porosity
- broken down or partially broken down materials are
called
3)
4)
5) Other: Plants, animals, bacteria, fungi, mycorrhizae,
protozoans
Can alter the soil by:
- adding
- breaking down and decompose materials
– tunnels – earthworms – their poop is
called
- disrupt soil
and
–
burrows and holes (larger animals)
- Page 331
Changes in Soil:
- continued weathering of parent material –
- erosion of soil –
- deposition of organic materials
– changes pH – alters nutrient uptake
by plants
Soil Horizons:
Layers of Soil from Surface Down:
- denoted by the letters
.
, with some immature soils
having none. Most have at least three of these (
).
1)
: top horizon - may not be present
- comprised of
- normally found in forest soils, where dead leaves and
other detritus can build up on a yearly basis
2)
: where the organic material is
in
with the inorganic material
- usually darker in color
- generally be fertile for plant life
3)
: below the A in
communities
- a result of water becoming acidic as it passes through the O
and A horizons and then leaching minerals out of the soil
4)
: where the
- can be very thick and tightly pored, resulting in
that can very effectively impede the flow of water through it.
5)
: contains the
Types of Soil:
1)
:colder climates, lots of precipitation, good
drainage, evergreen forests, layer of acidic litter
___________ in O-horizon, no A horizon, low fertility
2)
: found in grassland areas
- have a relatively rich, dark-colored A horizon zone as a
result of the organic matter from the being added from the grass.
- fertile nature of these soils makes them excellent media for
growing grain crops. __________________
3) _____________: dry for very long periods of time
- deserts, hot dry climates, layer of pebbles on surface, thin A
horizon
- high calcium carbonate concentration, with layers of clay,
silica, salt, and gypsum in the subsurface regions
4) _____________:heavily oxidized soils found in tropical and
subtropical rainforest
- soils have undergone heavy amounts of weathering and are
very low in fertility because water has leached most of the other
minerals out of the soil
- very thin layer of organic material on the surface – rapid
decomposition and nutrient uptake by plants due to temperature
and rainfall
5) _____________: temperate deciduous forests – hot summer,
cold winter
- leaves and detritus litter O-horizon
- A-horizon rich with humic materials
– decomposition is slower due to colder seasons
Soil Chemistry, Conservation and Agricultural Practices
Soil Chemistry:
Soil particles are
charged
- bind to
ions
negative ions – high ________________
_____________________________________
:
- plants may
to the soil particles
- in order to obtain the cations, plants release
if they are
from
The resulting
into the water solution and can then be
absorbed by the plant.
Soil Erosion and Degradation
: movement of soil components from one place to
another
Natural:
Most soil erosion is caused by moving water:
1. Sheet erosion – wide flow
2. Rill erosion – fast flowing little rivulets
3. Gully erosion – rivulets joining together cutting deeper and
wider channels (gullies)
Increasing Rate of Erosion:
-
– roots hold soil in place
Human Impact:
Impact of Soil Erosion:
for plant growth
ditches, boat channels, reservoirs, and
lakes.
- Sediment laden water is
Soil Erosion in the U.S.
 About 1/3 of nation's original prime topsoil has been washed
or blown into streams, lakes and oceans – mostly as the result
of over cultivation, overgrazing and deforestation.
 Soil on cultivated land is eroding 16 times faster than it can
form. erosion rate is even faster in heavily farmed areas
(Great Plains)
Desertification
 process whereby
– and results
primarily from human activities.
Practices that leave topsoil vulnerable to desertification:
1. overgrazing
2. deforestation without _____________
3. surface mining without _______________
4. irrigation techniques
5. _______________
6. farming on land that has _________________________
7. ____________________ by farm machinery and cattle
hooves
Slowing Desertification
Plant trees, grasses to anchor soil and hold water
Solutions: Soil Conservation
Soil Conservation
 involves reducing soil erosion and restoring soil fertility
 keep the soil covered with vegetation
Soil Conservation Farming Practices:
Conventional vs. Conservative Farming
 land is
to make a planting surface.
 land is usually plowed in the

soil to the
off and wind erosion
and smoothed
, left bare during the
which
run-
(minimum-tillage or no-till
farming)
 special tillers
without turning
, previous
crop residues and any cover vegetation
 special planting machines
seeds, fertilizers and
weed killers into
made in the unplowed soil.
 Main Benefit:
Added Benefits of No-Till Farming
 saves fuel
 cuts costs
 holds more water in the soil
 Prevents compaction of soil
a series of
– reduces erosion on steep slopes - converted into
that run across the
 Retains
by controlling
 Good choice for
– on
 plowing and planting crops in
the sloped contour of the land.
 A
alternates with another crop (a
grass or grass-legume mixture).
 The __________
that erodes from the
 They
and help
prevent the spread of pests and plant diseases. Soybeans and
alfalfa help restore soil fertility.
(
)
 is a form of
 several crops are
or shrubs that provide fruit or fuel
wood.
 The trees provide shade (helps to retain moisture).
 Trimmings from the trees and shrubs provide mulch (green
manure) for the crops.
Gully Reclamation, Windbreaks, Land Classification and
PAM Reduce Soil Erosion
 restore sloping bare land on which water runoff quickly
creates gullies
 plant fast growing plants, shrubs, vines and trees to stabilize
soil
 cover the soil with netting, fibers or hydromulch to hold soil
in place until plants can be established
(shelterbelts)
 reduce wind erosion
 long rows of trees
- used to sharply reduce erosion of some irrigated fields
- can reduce erosion by 70-99%
- increases cohesiveness of surface soil particles
Maintaining and Restoring Soil Fertility
– partially
lost by
.

fertilizer – from plant and animal materials

fertilizer -produced from various
minerals
Three basic types of organic fertilizer:
1.
 Dung and urine of cattle, horses, poultry and other farm
animals
 improves soil texture, adds organic nitrogen, stimulates
beneficial soil bacteria and fungi
2.
 fresh or growing green vegetation plowed into the soil to
increase organic matter and humus available to the next
crop
 weeds, grasses, clover, legumes, alfalfa, soybeans
3.
- rich natural fertilizer and soil conditioner
- aerates soil
- improves its ability to retain water and nutrients
- helps prevent erosion
- prevents nutrients from being wasted in landfills
 Plant corn, tobacco or cotton
.
 Following year plant
to add nitrogen to the
soil (soybeans, oats, rye, barley, sorghum).
 Also helps reduce crop losses to insects by presenting them
with a changing target.
Inorganic Fertilizers
Advantages:
Disadvantages
 Do not add
to the soil (so organic content of
soil will decrease) and soil will become
.
 Decreased
leads to reduced oxygen content
and prevent added fertilizer from being taken up efficiently.
 Usually supply only
 Cause
near streams.
 Rainwater leaches
especially on sloped land
into the groundwater.