OPTION - UNIT 7 GEOECOLOGY

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OPTION - UNIT 7 GEOECOLOGY
THE NATURAL ENVIRONMENT
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Syllabus Links - Soils

• Core 1.2 Weathering and Erosion
• Core 1.7 Human Interaction
• Core 2.2 Physical Processes
• Irish regions
• European Regions
• Continental / sub-continental region
• Core 3 Fieldwork

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Syllabus Links - Biomes

• Core 2.2 Continental / sub-continental
  region
• Elective 4.5 Environmental Impact

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7.1 SOILS Development

• Weathering of Rocks in Situ
• Re-deposited Weathered
• Material

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7.1 SOILS Development - Profiles
General
O Organic Layer consists of plant
litter and humus Not present in cultivated
fields A Topsoil consists of humus and
minerals The ploughed layer B Subsoil
low in organic material C Transition Area
between soil and parent material consists of
partially disintegrated bedrock
R Bedrock
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7.1 SOILS Development - Profiles
Brown Earth Source ENCARTA
Tropical Red Soil
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7.1 SOILS Development

• CHARACTERISTICS
• Texture
• Colour
• Structure
• Water Content
• Organic Content
• Water Retention
• Etc.

• COMPOSITION
• Mineral Matter
• Organic matter
• Water
• Air

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7.1 SOILS Composition
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7.1 SOILS Characteristics Texture

• Texture refers to the proportions of sand, silt
  and clay present.
• Texture determines the percolation and water
  retention qualities of the soil which influences
  the ability of the soil to retain nutrients
• Texture also determines how roots of plants are
  able to penetrate the soil

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7.1 SOILS Characteristics - Texture
Particle Size Clay Less than 0.002mm Silt
0.002 0.02mm Sand 0.02 2.0mm
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7.1 SOILS Characteristics Determining Soil
Texture

• Fill a screw topped clear glass jar two thirds
  full with soil
• Add water until jar is almost full
• Shake the jar for 1 minute approx.
• Leave the jar to settle for 24 hours

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Clay
90
80
Silt
70
Fine Sand
60
50
40
30
Coarse Sand
20
10
0
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7.1 SOILS Characteristics - Texture
Sample Sand 70 Clay 20 Silt 10
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7.1 SOILS Characteristics Texture

• Sandy Soils
• Generally loose coarse particles easy to
  cultivate
• Good drainage and aeration
• Prone to leaching
• Poor water retention makes them prone to drought
• Easily eroded by water when wet and wind when dry
• Silty Soils
• Generally loose finer particles
• Better water retention than the coarser sandy
  soil
• Tend to lack nutrients which hinders seed
  germination
• Easily eroded by heavy rainfall

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7.1 SOILS Characteristics Texture

• Clay Soils
• Very fine bonded particles
• Poor drainage and aeration
• Prone to water-logging
• Sticky when wet
• Very hard when dried out
• Loam Soils
• Equal proportions of sand, silt and clay
• Good drainage and aeration properties
• Retain nutrients and moisture
• Easily cultivated

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7.1 SOILS Characteristics Structure

• Structure refers to the shape and size of the
  solid grains of the soil
• Structure determines
• How easily soil is worked for agriculture
• How it resists erosion
• How easily air, water and living organisms can
  circulate through the soil

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7.1 SOILS Characteristics Structure

• Single Grained Structure
• Associated with sandy soils
• Water, air and organisms can pass through it
  easily
• Roots can spread out into the soil easily
• Water retention is poor - Nutrient retention is
  poor
• Prone to leaching
• Vulnerable to drought

Single grained
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7.1 SOILS Characteristics Structure

• Crumby Structure
• Associated with good agricultural land loam
  soils
• Water, air and organisms can pass through crumby
  soils easily
• Roots can spread out into the soil easily
• Water retention is good as it is soaked up by the
  crumbs of soil Nutrient retention good

Crumb 1 - 5mm
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7.1 SOILS Characteristics Structure

• Massive Structure
• Usually associated with clay type soils
• Water, air and organisms can not pass through
  this type of soil easily
• Roots have difficulty penetrating the large lumps
  of clay
• Soils are often waterlogged after periods of rain
• Soil dries into hard clumps after a dry period

Massive
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7.1 SOILS Characteristics pH value
pH potential Hydrogen ions
pH value of 7 neutral
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7.1 SOILS Characteristics pH value

• pH is a measure of acidity or alkalinity
• Low pH value Acidic Soil
• Leached by heavy rainfall - lacks calcium,
  nitrogen, magnesium and potassium stunted
  growth
• Discourages living organisms reducing rate of
  plant breakdown
• Formation of peat
• At very low pH levels aluminium is dissolved by
  acids poisonous to some plants

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7.1 SOILS Characteristics pH value

• High pH value Alkaline Soil
• Develops on limestone landscapes high
  concentration of calcium
• Deficiency of iron and boron distorted growth
• pH 7 Neutral Soil
• Neutral or slightly acidic soil is most suitable
  for farming
• Encourages growth of bacteria vital for
  releasing nutrients from organic material

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7.2 SOILS Influences

• Affected by
• Immediate Environment
• Processes Including Human Interference

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7.2 SOILS InfluencesImmediate Environment

• Topography
• Altitude
• Slope
• Aspect

• Climate
• Global Pattern of Soils
• Parent Material
• Rock type

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7.2 SOILS Global Climate Types
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7.2 SOILS Global Patterns
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7.2 SOILS European Patterns
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7.2 SOILS InfluencesImmediate Environment -
Topography
Horizon Formation
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7.2 SOILS InfluencesProcesses incl. Human
Interference

• Natural
• Weathering
• Soil Erosion
• Leaching
• Humification
• Podzolisation
• Laterisation
• Calcification

• Human
• Over-cropping
• Over-grazing
• Desertification
• Conservation

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7.2 SOILS InfluencesProcesses - Weathering
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7.2 SOILS InfluencesProcesses - Erosion
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7.2 SOILS Influences - Processes

• Humification organic matter rots to form humus
• Calcification very little leaching allows
  calcium to accumulate close to the surface
  forming fertile soil
• Salinisation moisture is brought to the surface
  by capillary action, but evaporates quickly and
  the dissolved salts are deposited in the upper
  layer of soil

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7.2 SOILS Influences Processes

• Leaching rainwater carries soluble minerals and
  organic matter down through the soil profile
• Podzolisation leaching by acidic water which
  can dissolve almost all the soil constituents,
  may leave the A Horizon infertile and grey in
  colour
• Laterisation leaching by non-acidic water
  leaves iron and aluminium close to the surface
  giving the soil a reddish colour
• Gleying lack of oxygen in waterlogged soils
  slows down the rotting process and organic matter
  accumulates at the top of the profile

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7.2 SOILS Influences Human Interference

• Human
• Over-cropping
• Over-grazing
• Desertification
• Conservation

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7.2 SOILS Human Interference
Clearing Bush-land in Australia
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7.2 SOILS Human Interference
Erosion caused by raindrops on bare land
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7.2 SOILS Human Interference
Erosion caused by tilling dry land
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7.2 SOILS Human Interference
Erosion caused by wind
Source Seafriends.org.nz
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7.2 SOILS Human Interference
Livestock Damage
Source Seafriends.org.nz
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7.2 SOILS Human Interference
Soil Protection
Source Seafriends.org.nz
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7.2 SOILS Human Interference
Erosion caused by tilling hill slopes
Source Seafriends.org.nz
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7.2 SOILS Human Interference
Contour ploughing Strip cropping
Source Seafriends.org.nz
Terracing Paddy (Padi) fields
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7.2 SOILS Human Interference
Soil Protection
Source Seafriends.org.nz
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7.2 SOILS Human Interference
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7.2 SOILS Human Interference
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7.2 SOILS Human Interference
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7.2 SOILS Human Interference
Desertification Mediterranean Region
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7.2 SOILS Human Interference
Desertification Europe
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7.2 SOILS Human Interference
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7.3 BIOMES World Regions

• Characterised by inter-relationships of
• Climate
• Soils
• Plants
• Animals

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7.3 BIOMES World Climates Types
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7.3 BIOMES World Regions
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7.3 BIOMES World Regions
Deciduous Forest
Desert
Taiga
Tropical Rain Forest
Grassland
Tundra
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7.3 BIOMES World Regions Tropical Rain Forest
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7.3 BIOMES World Regions Tropical Rain Forest
- Climate
Belize - Temps
Belize - Rainfall
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7.3 BIOMES World Regions Tropical Rain Forest
- Climate
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7.3 BIOMES World Regions Tropical Rain Forest
- Soils
Thick leaf layer rots quickly and deeply due to
heat and moisture. Removal of vegetation cover
causes leaching.
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7.3 BIOMES World Regions Tropical Rain Forest
- Plants
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7.3 BIOMES World Regions Tropical Rain Forest
- Animals
Squirrel
Black Jaguar
Woolly Monkey
Monkey
Macaw
Owl Butterfly
Grasshopper
Gecko
Source A Place Out of Time Tropical Rainforests
and the Perils They FaceRhett A. Butler - San
Francisco, CA.Unpublished - 2001. (Mongabay.com)
Boa
Caiman
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7.4 BIOMES World Regions

• EFFECTS OF HUMAN ACTIVITIES
• Early Settlement Clearing Forests
• Felling of Tropical Rain Forests
• Intensive Agriculture
• Industrial Development

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7.4 BIOMES Human ActivitiesEarly Settlement
Clearing Forests

• European Forests
• Irish Forests
• Started in Neolithic Age
• Mid 1800s almost devoid of forest cover
• 1900 only 1 forest cover
• 2003 - 9.4
• EU average 31

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7.4 BIOMES Human ActivitiesEarly Settlement
Clearing Forests
Country Forest Cover ( of land area) 2003
Ireland 9.4
Netherlands 9.5
Denmark 12.7
Belgium 22.4
Germany 30.2
France 31.6
Sweden 73.5
Finland 75.5
Source OECD
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7.4 BIOMES Human ActivitiesEarly Settlement
Clearing Forests
Dark Green gt 40 cover Mid Green 10 40
cover Light Green woodland, shrubland
and bushland
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7.4 BIOMES Human ActivitiesClearing Forests
Change in forested land 1990-2000 by region total land area (m ha) total forest 1990 (m ha) total forest 2000 (m ha) change 1990-2000 (m ha) change per year
Africa 2 963.30 702.50 649.90 -52.60 -0.70
Asia and the Pacific 3 463.20 734.00 726.30 -7.70 -0.10
Europe 2 359.40 1 042.00 1 051.3 9.30 0.10
Latin America and the Caribbean 2 017.80 1 011.00 964.40 -46.60 -0.50
North America 1 838.00 466.70 470.10 3.40 0.10
West Asia 372.40 3.60 3.70 0.10 0.00
           
World 13 014.10 3 960.00 3 866.10 -93.90 -0.24
Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding Source compiled from FAO 2001b Note numbers may not add due to rounding
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7.4 BIOMES Human ActivitiesClearing Forests
Average Annual 1990 - 2000
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7.4 BIOMES Human ActivitiesFelling Tropical
Rain Forests

• Importance of Tropical Rain Forests
• Home to Tribal Cultures that have survived for
  thousands of years
• Home to 50 of plant and animal species
• Winter home to birds that breed in temperate
  climates
• Help to reduce Global CO2 levels
• Help to maintain global rain and weather patterns

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7.4 BIOMES Human ActivitiesFelling Tropical
Rain Forests

• Reasons for Felling
• Firewood, charcoal, building materials, furniture
  
• Conversion to pasture for cattle ranching
• Mining for gold, bauxite (aluminium) etc.
• Cultivation of Cash Crops

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7.4 BIOMES Human ActivitiesFelling Tropical
Rain Forests
Brazil Source UNEP
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7.4 BIOMES Human ActivitiesFelling Tropical
Rain Forests
Argentina Source UNEP
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7.4 BIOMES Human ActivitiesFelling Tropical
Rain Forests
Bolivia Source UNEP
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7.4 BIOMES Human ActivitiesIntensive
Agricultural Practices
Bolivia Source UNEP
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7.4 BIOMES Human ActivitiesIndustrial
Development - Urbanisation
Urban Population by Region
Nearly half the world population now lives in
urban areas. Africa, and Asia and the Pacific,
are the worlds least urbanized regions, North
America, Europe, and Latin America the most
urbanized Source compiled from United Nations
Population Division 2001b
While all regions are still urbanizing, the rate
at which most are doing so is falling, although
rates are changing little in Africa and are
actually increasing in North America Source
compiled from United Nations Population Division
2001b
Annual Increase by Region
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7.4 BIOMES Human ActivitiesIndustrial
Development - Urbanisation
Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000 Distribution of global population () by size of settlement, 1975 and 2000
    rural areas rural areas lt 1 million lt 1 million 1- 5 million 1- 5 million gt 5 million gt 5 million
    1975 2000 1975 2000 1975 2000 1975 2000
world 62.1 53 25.1 28.5 8 11.6 4.8 6.9
developed regions 30 24 46.8 48.1 13.9 18.5 9.3 9.5
developing regions 73.2 60.1 17.6 23.7 6 10 3.2 6.3
Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a Source United Nations Population Division 2001a
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7.4 BIOMES Human ActivitiesIndustrial
Development - Air Pollution

• Trends in Atmospheric Concentrations and
• Anthropogenic Emissions of Carbon Dioxide

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7.4 BIOMES Human ActivitiesIndustrial
Development Air Pollution

• World Carbon Dioxide Emissions by Region,
  2001-2025 (Million Metric Tons of Carbon
  Equivalent)

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7.4 BIOMES Human ActivitiesIndustrial
Development Air Pollution

• World Carbon Dioxide Emissions 1999
• Metric Tons of Carbon Equivalent per capita

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7.4 BIOMES Human ActivitiesIndustrial
Development Acid Rain
Source angelfire.com
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7.4 BIOMES Human ActivitiesIndustrial
Development Acid Rain

• Effects of Acid Rain

Source angelfire.com
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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Rivers and Lakes Faecal Coliforms

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Rivers and Lakes pH values

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Fresh Water Stress (where consumption exceeds 10
  of total supply)

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Rivers and Lakes

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Rivers and Lakes

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Coasts and Seas

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7.4 BIOMES Human ActivitiesIndustrial
Development - Water Pollution

• Pollution of Coasts and Seas

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Coasts and Seas

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7.4 BIOMES Human ActivitiesIndustrial
Development Water Pollution

• Pollution of Coasts and Seas

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7.4 BIOMES Human ActivitiesVanishing Wilderness
World Ecosystems Undisturbed Partially Disturbed Human Dominated
51.9 24.2 23.9
Adjusted for Rock, Ice Barren Land 27 36.7 36.3
Source Hannah et Al 1994