Human Impacts on the environment Flashcards
What are the consequences of overfishing?
-Depletion of Fish Stocks: Reduced populations of target species.
-Ecosystem Imbalance: Altered food chains and negative impacts on other species.
-Economic Loss: Decline in fisheries’ profitability and livelihoods.
-Social Impacts: Affecting communities dependent on fishing for food and income.
Methods to reduce overfishing?
-Fishing Quotas: Establish limits on the quantity of fish that can be caught.
-Marine Protected Areas: Create no-fishing zones to allow fish populations to recover.
-Sustainable Practices: Use selective fishing gear and avoid bycatch.
-Aquaculture: Promote responsible fish farming to reduce pressure on wild fish stocks.
Reasons for deforestation occuring?
-Agricultural Expansion: Clearing forests for agriculture and livestock grazing.
-Logging: Timber extraction for wood and paper products.
-Infrastructure Development: Building roads, highways, and urban areas.
-Mining: Extracting minerals and resources from forested areas.
Consequences of deforestation?
-Loss of Biodiversity: Disruption of ecosystems and habitat destruction.
-Climate Change: Reduced carbon sequestration and increased greenhouse gas emissions.
-Soil Erosion: Exposed soil becomes susceptible to erosion and degradation.
-Disruption of Water Cycle: Altered rainfall patterns and increased risk of flooding.
Methods of reducing deforestation?
-Sustainable Logging: Implement responsible logging practices.
-Reforestation: Planting trees to restore damaged areas.
-Protected Areas: Establish and maintain protected forest reserves.
-Consumer Choices: Support sustainable and certified wood products.
What is the definition of biodiversity?
Variety of species present in an ecosystem. This can be calculated as the number of species in a specific area.
Why does natural selection lead to species becoming endangered (+ examples)?
Existing species do not have the ability to survive in a changing environment.
- Saber Tooth cat, woolly mammoth, cave bear
Why does deforestation lead to species becoming endangered (+examples)?
Removal of large areas of forests for a variety of reasons such as for oil palm plantations in Borneo
- Orangutan
Why does habitat destruction lead to species becoming endangered (+examples)?
Wetland drainage for agricultural land or land for building, reducing habitable areas, so population declines
- Western Black Rhino
Why does loss of hedgerows lead to species becoming endangered (+examples)?
To increase field size for the use of machinery and wildlife in hedgerows are adapted for life in that environment specifically
- dormice
Why does pollution (such as PCBs and Oil) lead to species becoming endangered?
Unregulated industry polluting rivers, pollution can change the environment that it becomes uninhabitable for organisms living there
- Baiji River Dolphin
Why does hunting and collecting lead to species becoming endangered?
They collect for profits or food, can prevent mating seasons that restore numbers, so population declines
- elephants are hunted for ivory
Why does competition from domestic animals lead to species becoming endangered?
Introduced domesticated animals for food competing with native species for prey , can transmit diseases and kill wild animals
- Goats on the Galapagos competing for grazing sites with tortoises
What is conservation?
the maintenance of the biosphere and enhancement of biodiversity locally
What does the conservation of species ensure?
Ensures the conservation of existing gene pools
Conservation method: Nature reserves
Nature reserves protect areas rich in biodiversity from being damaged or destroyed from development
Managed to improve and maintain the quality of habitat, ensuring species action plans are having intended results
Conservation method: SSSIs
SSSIs cover 50% of habitat considered to be of conservation priority in ENGLAND (e.g. coastal, woodland, wetland, heathland, etc)
Usually managed privately leading to less human disruption
Conservation method: Restriction on trade
e.g. CITES
International agreements between governments that prevents the trade in organisms whether dead, alive or part of the organism
This reduces the number of species killed, less harvesting of the organism and increases biodiversity
E.g. a ban of elephant ivory
Conservation method: Zoo breeding programmes
Animals on the edge of extinction can be taken into zoos and bred before being returned to the habitat
allows animals from several subspecies to be bred
Captive breeding means that animals can be outbred with animals from different zoos (preventing inbreeding and no genetic deformation)
Conservation method: Sperm or seed banks
Sperm and seed banks store material in a safe environment and insure against damage or loss of a habitat (conserves rare species)
Damage to ecosystems can be repaired and animals which have small populations may be boosted by using sperm from a wider variety of individuals increasing the potential gene pool and avoiding bottleneck problems. (increase genetic variation)
Conservation method: Reintroduction
Releasing species into the wild from captivity to establish healthy wild populations
Individuals can be reintroduced to where a species has been lost of the conditions are still favourable for the success of the species (e.g. Large blue butterfly)
Conservation method: Pollution Control
Eutrophication from transport and agriculture
acid rain from air pollution (acidifies soil and water)
chemical pollutants leach into the soil and water
oil pollution affects marine ecosystems
reducing pollution improves health and state of the environment
How do pesticides increase agricultural production?
Reduces competition from other plants or weeds. Reduces damage & disease, increases yield & quality
How do pesticides affect the environment?
Less biodiversity as weeds and animals they support are killed.
May kill pollinators (kills bees) & natural predators of pests.
Can spread to other areas leading to contamination (e.g. water), animals are poisoned and effects the food chain
How do artificial fertilisers increase agricultural production?
Higher yields.
Nutrients no longer limiting.
No need to rotate crops allows constant growth of most valuable crop.
How does artificial fertilisers affect the environment?
Reduces biodiversity in pastures as grass grows rapidly and out-competes wild crops.
Wash to watercourses cause eutrophication
Fossil fuels required to manufacture and transport them
Alter soil pH reducing the quality of the soil
