Chapter 6 Human Impact On The Environment Flashcards
What are the reasons why some species are threatened?
Natural selection Loss of habitat (human or natural causes) Over hunting by humans Competition Pollution
Define conservation
The protection, preservation, management and restoration of natural habitats and their ecological communities, to enhance biodiversity while allowing for suitable human activity.
What are the 6 ways conservation is carried out ?
Protecting habitats International cooperation restricting trade Gene banks Education Legislation Ecotourism
What is ecotourism?
Responsible travel to natural areas that conserves the environment and improves the well-being of local people
Why is conservation needed?
Ethical reasons (uniqueness of each environment/organism is valuable)
Agriculture/horticulture (conservation prevents the loss of important alleles such as resistance to cold/disease)
Conservation prevent extinction of some species
Potential medical uses (drugs such as quinine were synthesised by plants, thus future medicine may be stopped if plants are extinct)
How does agricultural exploitation affect the environment?
Monocultures reduce biodiversity, removal of hedge grows for machinery destroys specialised habitats, overgrazing by cattle causes grassland to become unsustainable (desertification).
How does deforestation affect the environment?
Soil erosion (removal of valuable nutrients) which prevents crop growth (desertification),deforestation of uplands cause lowland flooding, habitat loss causes low biodiversity, reduces rate of photosynthesis increasing CO2 in atmosphere contributing to climate change.
How can deforestation be controlled?
Coppicing: cutting down trees close to the ground and leaving them to regrow for several years
Selective cutting: felling some trees, leaving others in place
Planting trees the optimum distance part to prevent intraspecific competition
How does overfishing affect the environment?
Drift netting traps non target species such as dolphins/turtles, trawling equipment damages ocean bed and therefore the habitats of molluscs.
How can overfishing be controlled?
Larger mesh size nets allowing young and small fish to survive
Exclusion zones allowing fish to reproduce
Fish farming (breeding fish which allows natural fish populations to remain stable, and fish farming has a lower carbon footprint compared to livestock farming)
