Earth's Environment and Climate Systems Flashcards
What happens in the Gudjewg season (Jan, Feb)?
Massive rainfall
Great heat and humidity
Plant and animal life is very active
What happens in the Banggereng season (Mar)?
Rain is slowing
Strong wind storms can flatten out long grass
Plants are in fruit
Many young have animals to care for
What happens in the Yegge season (Apr, May)
Calm winds and morning mists
Waterlilies cover billabongs across Kakadu
Indigenous Australians burn the bush to encourage new growth and reduce the danger of fire later in the year
What happens in the Wurrgeng season (Jun, Jul)?
Cold time in Kakadu (30°C)
Land is drying out very quickly
Birds and animals move closer to billabongs as water disappears
What happens in the Gurrung season (Aug, Sep)?
Windless and hot
Snakes and turtles are hunted
Clouds begin to form-preparation for coming wet season
What happens in the Gunumaleng season (Oct, Nov, Dec)?
Period before heavy rains
Clouds form
Afternoon rain begin to clean billabongs and streams
People move to higher ground for shelter
Define soil.
Part of the regolith
Mixture of weathered rock, organic matter, air and water
How does soil differ from the rest of the regolith?
High content of organic matter Roots of plants Soil organisms (eg: worms) Weathering is more intense Has horizons (horizontal layers)
What do soils consist of?
Mineral matter
Organic matter
Soil water
Soil air
Describe the mineral matter found in soils.
From mechanical and chemical weathering
Particles vary from pebbles to colloidal clay particles
Describe the organic matter found in soils.
From decaying organic matter (humus when partly decomposed)
Helps retain water, provides microorganisms with food and keeps soil friable
Describe the water found in soils.
Found in pore spaces between particles
Is a solution of many chemicals
Hygroscopic water - clings to particles
Gravitational water - moves towards aquifers
Capillary water - moves upwards by capillary action
Major source of water for plants
Enables plants to absorb nutrients
Describe the air found in soils.
Found in pore spaces
Supplies oxygen to plant roots and organisms
List the types of soil texture from coarse to fine.
Clay, silt, fine sand, coarse sand, fine gravel
What are the structures of soils?
Platy (thin, horizontal plates)
Columnar/prismatic (vertical pillars)
Blocky/nuciform (angular blocks)
Granular/crumb (round aggregates)
How does humus affect soil colour?
Content and chemical composition
Define permeability.
Ability of soils to transmit water
Varies with texture
Define porosity.
The pore space between particles
Indicates how much water can be held
Identify and explain 2 reasons why land cover changes over time.
Humans modify land to obtain resources especially driven by population growth.
Natural alterations occur from climate change, forest fires and volcanic eruptions.
Identify 2 ways in which land cover change has occurred in Australia and the reasons for these changes.
European Occupation of Australia and the application of commercial farming using machines.
Indigenous hunting techniques (firestick farming) -
reduced forest areas and created open woodland and grassland.
Explain the impact of fragmentation or the loss of land on natural ecosystems.
Reduces the natural environment to small separate parcels surrounded by crops, rangelands and urban settlements.
Separates breeding populations of animals reducing genetic and species diversity.
Identify and discuss two ways in which land cover change has the potential to result in conflict between different land use activities.
Disappearance of the Aral Sea in Russia - reduced available water for irrigation, domestic and industrial users - creates potential conflict between these activities.
Intensive farming on the edge of cities is under pressure from urban development.
Outline how governments may influence land cover change.
Promotion of urban development
Allowing clearing to increase cropland
Allowing too much irrigation water to be taken from river systems – Murray-Darling basin
Controlling clearing of bushland to conserve natural environment
Outline land cover change in remote forests.
Lower precipitation
Dense tree cover
Virtually no human habitation (max 1 person/km²)
Mostly untouched
Potential for high pastoral use - severe cutting where used for timber resource
Higher biodiversity
Outline land cover change in populated forests.
High precipitation Extensive tree cover Low non-urban population density (max 10 people/km²) Closer to human population Potential for cropping and pastoral uses High biodiversity
Summarise the main effects and of agricultural croplands.
Most extensive land use (covers larger area), varies from intensive to extensive farming types
Intensive (market gardening, orcharding, dairying) has greater change
Closer to settlement
Near total removal of vegetation
Irrigation in high seasonal rainfall areas
Variety of rural landscapes
Summarise the main effects of rangelands.
More remote Use of natural pastures, less clearing Low population densities (remote settlements) Less evidence of human activity Overstocking can damage vegetation cover
Outline the land cover changes associated with Australia’s urban growth.
Extensive clearing Dominant built landscape Negligible agricultural activity Less influenced by natural environment Invasion of surrounding farmland
Discuss the significance of urban development as a global driver of land cover change.
Half world’s population lives in urban settlements (occupy 7% of the ice-free land).
Require a large amount of resources - pressure on remaining land.
Urbanisation is increasing (China).
Some cities are so large they are merging (Bosnywash in the USA).
Identify and describe three ways in which freshwater ecosystems are altered by human activity.
Damming of rivers for irrigation, domestic and industrial uses - alters the drainage system.
Over use of potable water.
Eutrophication due to nutrients (fertiliser) in the runoff.
