Key Environmental Cycles and the Effects of Human Activity on the Environment Flashcards
Define Environment
ISO 14001:2015 – the surroundings in which an organisation operates, including air, water, land, flora, fauna, humans and their relationships………surroundings can extend from within an organisation to local, regional, global and can be described in terms of biodiversity, ecosystems, climate and other characteristics
Describe the Carbon Cycle
The carbon cycle is described as the ways in which carbon moves between plants and animals and the physical components of the environment (atmosphere, ground and water bodies)
What are the major stores of carbon?
these are linked by the carbon exchange pathways
G - geological
O - Oceans
A - Atmosphere
L - Land Biosphere
Atmosphere - How Carbon naturally enters and leaves this system
Carbon exits (the atmosphere) by:
> photosynthesis
> dissolving in rain water
> directly into water bodies - and then absorbed by rocks
Carbon Enters (the atmosphere)
> respiration of plants and animals
> volcanic activity
Land Biosphere - How Carbon naturally enters and leaves this system
Carbon Leaves (the Land Biosphere)
> respiration of plants and animals
Carbon Enters (the Land Biosphere)
> the death of plants and animals
> waste carbon consumed by bacteria/fungi - they then respirate
Oceans - How Carbon naturally enters and leaves this system
Carbon Enters (the Ocean)
> mainly through dissolution
> then converted to organic carbon by photosynthesis and enters the food chain
> it can then pass through
> accumulate in shells as calcium carbonate
Geological - How Carbon naturally enters and leaves this system
most carbon stored in the upper mantle
> 80% in calcium carbonated rocks
> 20% in ketones (oil, gas, coal)
Leaves - by volcanic activity
Effects of Human Activity on Carbon Cycle
> burning of fossil fuels and biomass - releasing carbon dioxide
> deforestation and other changes to land use - removing a carbon sink carbonate rocks used in cement manufacture
Nitrogen cycle - why vital to all life processes on Earth
proteins and genetic material (DNA and RNA)
How can Nitrogen be extracted from the atmosphere?
> lighting - causes di-atomic nitrogen particles to divide
> The Haber Process - chemical process to react Nitrogen and Hydrogen reaction to manufacture Ammonia
> Nitrogen Fixing Bacteria - present in soil and legumous plant root nodules
> Excretion and Egestion from animals - nitrogen compounds returned to the soil
> Animal and plant decay - nitrogen compounds returned to the soil
Effects of Human Activity on the Nitrogen Cycle
> Fertiliser run off and sewage discharge causing nutrient enrichment
> Fossil Fuel combustion resulting in acidification
> Emissions of ammonia from intensive (pig & chicken) farming
What is eutrophication?
Nutrient enrichment
Why is Phosphorus important?
It is an integral part of the energy production in all living cells
What are the stages of the phosphorus cycle?
> rocks and other terrestrial deposits weathered over time leading to discharge of phosphorus into water bodies
> phosphorous (in phosphate form) extracted from soil by plants
> animals fed on those plants take up phosphorus
> discharge of phosphorus to soil & water by animal excretion
> following death bacteria & fungi aid decomposition which changes form of phosphorus and transfers back to soil
What are the effects of Human Activity on the Phosphorus Cycle?
> phosphorus containing fertilisers can run off into rivers and cause nutrient enrichment
> increased erosion - due to deforestation - release phosphorus resulting in nutrient enrichment
Define the Hydrological Cycle
The process of water movement around the earth
Describe the Steps in the Hydrological Cycle
> initial input into the cycle by precipitation
> plant roots take up water that has seeped into the soil
> water can continue through soil horizon and into aquifers (water bearing rocks)
> As both processes occuring water is evaporating. Rises into atmosphere and becomes the vapour involved in condensation
How do humans effect the Hydrological Cycle?
> depletion of aquifers
> damming of rivers - which will harm fish and other aquatic organisms
> deforestation causing flooding by allowing unrestricted run off
> climate change altering the location and amount of water around the planet
> changes in land use increase or decrease the flow of water in a catchment
Define Ecology
The study of the relationships between and the interactions of living things to one another and their physical surroundings
Define Ecosystem
a community of interdependent organisms and the physical and chemcial environment they inhabit (eg estuaries/woodland)
How do Ecosystems Work?
energy and chemicals are constantly cycled through the system.
The system can be disrupted by pollutants which can enter the food chain and are eventually absorbed into our bodies
What is a food web?
A collection of food chains
Define Biodiversity
the diversity, or variety, of plants, animals and other living things in a particular area or region
What are the benefits of biodiversity?
> ecological
> Economic
> Cultural/spiritual/aesthetic
> Recreation/tourism
> Education/Information
