B17 - Biodiveristy And Ecosystems Flashcards
Carbon sinks - trapping of carbon
Forests - absorb CO2 via photosynthesis
Oceans - CO2 dissolved in water
- phytoplankton use carbon for their skeleton and shells
Peat bogs - lock away CO2, when burnt CO2 released back into the atmosphere
Peat bogs
• incompletely decomposed plant remains
• formed by waterlogging and lack of oxygen which effect the natural processes of decay
• preservation of matter due to limited oxygen to the matter as they have been water logged
• therefore microorganisms cannot fully decompose (lack of bacteria breaking down)
• bodies found
• when oxygen is removed, bacteria is no longer able to respire therefore reducing the rate of decomposition
Why does deforestation happen?
• population explosion - 8 billion people on Earth
• more people = more resources
• global warming = Earth gradually heating up because of increasing levels of greenhouse gases
Biodiversity
• 8.7 million species
• destruction of habitats (fishing, agriculture, manufacturing)
• exploitation of species - fishing, bogging, harvesting - population collapses due to high demand
• pollution - eutrophication
• alien species introduced
• rapid climate change - mass extinction events
• loss of sea ice
• alters weather patterns
3 ways biodiversity is reduced
• deforestation reduces biodiversity
• using peat bogs decreases biodiversity
• landfill destroys habitats - less biodiversity
What is global warming?
• result of the greenhouse effect
• solar radiation is infrared/ultraviolet
Infrared radiation can:
• emit
• absorb heat
Effects of climate change on biodiversity:
• loss of habitat
• rising sea levels destroy habits and reduce biodiversity in that area
• another effect is a change in the distribution of organisms
• as temperatures and rainfall patterns change, organisms may find that their range shrinks or completely disappears
• organisms migration patterns may also change due to a change in seasons
Breeding programmes for endangered species
• animals are bred in captivity to ensure a species survives
• individuals can sometimes be released into the wild to boost a population
• eg white rhinos/snow tigers
• RSPCA and WWF work to support animals
Protection and regeneration of rare habitats
• protecting habitats like mangroves in coastal regions, heathland and coral reefs
• helps preserve ecosystems and biodiversity in the area
Reintroduction of field margins and hedgerows
• introduce this on farms where only a single type of crop is grown
• field margins are where wild flowers/grasses grow
• provide habitat for wider variety of organisms that could survive
• arable
Reduction of deforestation and carbon dioxide emissions
• gov introduced regulations to reduce deforestation, especially for businesses
• reduce global warming
• CO2 is released by buisnesses
• in the Amazon
Recycling resources
• people are encouraged to recycle to reduce the amount of waste that gets dumped in landfill sites
• leaving ecosystems in place because less land is needed for landfill
• recycling plastic
• Different bins
Land pollution examples
• land fill
• deforestation
Water pollution examples
• oil spills
• eutrophication
• sewage/commerical waste
Air pollution
• combustion of fossil fuels
What is meant by abiotic/biotic factors?
The environment in which organisms live changes all the time. The things that change are either abiotic (non living) or biotic (living) factors. These can effect the community.
Examples of abiotic factors
Moisture level
Light intensity
Temperature
Carbon dioxide level for plants
Wind intensity and direction
Oxygen level for aquatic animals
Soil pH and mineral content
Example of how a change in an abiotic factor effects the community
• a decrease in light intensity, temperature or level of carbon dioxide could decrease the rate of photosynthesis in a plant species. This can affect plant growth and cause a decrease in the population size.
• a decrease in the mineral content of the soil. For example, a lack of nitrates could cause nutrient deficiencies. This could also affect plant growth and cause a decrease in the population size.
Examples of biotic factors
New predators arriving
Competition – one species may outcompete another, so that numbers are too low to breed
New pathogens
Availability of food
Examples of how changing biotic factors could affect the community
• a new predator could cause a decrease in the prey population
• red and grey squirrels live in the same habitat and eat the same food. Grey squirrels outcompete the red squirrels so the population of red squirrels is decreasing.
