Biodiversity and Ecosystems Flashcards
What would happen if any other species of animal or plant suddenly increased like humans?
Nature would tend to restore the balance
Predators lack of food, build-up of waste products or disease will reduce the population again
People’s use of the resources of the Earth
Use fossil fuels to generate electricity
Plastics, minerals from rocks and soil used to grow food
More people = more resources we use
Why has the human population grown so quickly?
Grow more food
Cure diseases
We have no natural predators
Humans effect on land and resources
More land used for buildings = more habitats destroyed
Land for farming = animals and plants destroyed
Quarries = reduce land available for organisms
Waste = polluted environment
Managing waste
Human bodily waste and rubbish from packing, uneaten food and disposable goods
Dumping of waste reduces land available for any other life apart from scavengers
Water = polluted by sewage
Air we breathe = polluted with smoke
Land = polluted by toxic chemicals from farms
Polluting of land
·More people = more bodily waste -> soil becomes polluted
· People produce household waste and industrial waste -> goes into landfills -> destroys natural habitats and toxic chemicals spread from waste to soil
· Weeds compete with crop plants -> animals and final pests eat them -> farmers project using chemicals to kill insects (pesticides) -> poisons get into soil -> rivers -> get into organisms that feed on plants in soil
Polluting the water
· Add fertilisers to soil -> stays fertile for years
· Untreated sewage pumped into sea -> High levels of nitrates in water -> Stimulate growth of algae and water plants (grow fast)
· Some plants die naturally others to competition -> big increase in microorganisms feeding on dead plants -> use up lot of oxygen during respiration
· Increase decomposers leads to fall in level of dissolves oxygen in water -> isn’t enough oxygen for fish and aerobic organisms
· Toxic chemicals from landfills and farming washed into waterway -> biaccumilation effect on aquatic food webs -> fail to breed and toxic chemicals in body build up -> now farmers use strict controls
· Pollution levels in water measured in pH and bio indicators (some species only found in very clean or very polluted water)
Formation of acid rain
Fossil fuels burnt
Contain sulphur and nitrogen impurities
React with oxygen
Form dilute sulphuric acid and nitric acid rain
Effects of acid rain
Soaks into soil destroys roots
Makes water acidic -> lakes become dead and no longer support life
Destroys flowers, leaves, buds and fruit on trees
Sulphur dioxide and nitrogen oxides are carried high in air by winds
How countries have reduced affect of acid rain
Stop vehicles, factories and power stations producing acidic gases
Low-sulphur petrol and diesel used in vehicles
Catalytic converters are fitted to remove polluting gases from a haunt fumes
Strict emissions set
Use gas > coal
Chimneys cleaned flue gases before released into atmosphere
Particulates
Increase solid solid particles in air
What does smoke pollution do
Particulates formed reflect sunlight so less light hits the surface of the Earth
Leads to cooling temperatures
Affects human health and damaged lungs
What is smog
Haze of small particles and acidic gases that can be seen in the air
Changing conditions due to human activity
CO2 levels increase
Plant availability to absorb CO2 decreasing
Speed changed and natural sink can’t cope
Greenhouse effect
Energy from sun warms Earth
Radiates energy back into space
CO2 and methane absorbs some energy as Earth cools down
Keeping atmosphere warm
