BY5.8 - Biodiversity and Endangered Species Flashcards
Where are the most biodiverse places on the planet?
Coral reefs and rain forests
- as you move from the poles to the equator, biodiversity increases
What is biodiversity?
A measure of the number of species on the planet
Why are large mammals (such as gorillas) threatened with extinction?
1) loss of habitat - deforestation
2) overhunting by humans
3) competition from introduced species
Why are other, smaller species threatened with extinction?
1) natural selection
2) deforestation - loss of hedgerows
3) pollution - PCBs and oil
4) Drainage of wetlands
Why is the conservation of species important?
to conserve potentially useful genes for future generations of humans as well as for the survival of the species itself
Why is each species genes important for humans?
They are a potential source of:
1) Food
2) Chemicals
3) disease resistant genes
4) Medicines
What steps have been taken to reduce the extinction of endangered species?
1) seed banks with seeds of traditional varieties of plants
2) sperm/ova banks
3) Rare breed societies - maintains old, less commercial animals
4) protection and breeding of endangered species in zoos
5) reintroduction programmes - red kites in wales
6) Habitat protection
7) International cooperation - restricting trade - ivory
What is agricultural exploitation?
The way in which food production has increased in efficiency and intensity
to maximise the yield from the land to meet human needs.
what are the conflicts that arise between farming and conservation?
1) Larger fields require hedgerow removal to allow machinery to manoeuvre, and more land used to grow crops
2) Monoculture - growing a single species of crop provides ideal conditions for crop pests and parasites so herbicides and pesticidesare used
3) Harvesting reduces recycling of nutrients, causing reduction in soil fertility/. Inorganic fertilisers are used, which lead to eutrophication
Why is deforestation needed?
1) Land cleared for subsistence farmers and cash crops
2) large scale timber extraction for building
3) Wood for fuel
4) Paper and packaging
5) Land cleared to build roads to provide transport infrastructure
What are the consequences of deforestation?
1) Soil erosion - increases desertification
2) Global Warming - Less CO2 removed from air by photosynthesis, co2 concentration increases in atmosphere, increasing the Greenhouse Effect
3) Loss of habitats -> reduction in biodiversity -> extinction
4) Loss of sources of plant chemicals which have medicinal properties
What are the Forestry Management methods to reduce the impact of deforestation?
1) allow natural regeneration
2) Coppicing/ selective cutting
3) Planting local tree species
4) control pests and diseases
How does global warming lead to a /reduction in biodiversity/
1) Change in rainfall patterns
2) Desertification
3) Loss of habitat
4) Reduction in Biodiversity
How does deforestation lead to a reduction in biodiversity
1) deforestation removes autotrophs
2) less photosynthesis occurs
3) more CO2 in atmosphere
4) Global Warming
5) reduction in biodiversity
How can we measure our contribution of CO2 to the atmosphere?
looking at our Carbon Footprint
What is a personal carbon footprint?
the total mass of CO2 an individual contributes to the atmosphere each year, through:
1) direct emissions - driving/heating/electricity
2) indirect emissions - using a product or service that required energy
what is a product/service carbon footprint?
how much energy a product or service requires to produce itself
What are the effects of overfishing?
1) Harvesting rate higher than fish birth rate
2) Fish population falls
3) Depletion of Young Fish so the breeding stock is unable to maintain previous population levels
4) loss of biodiversity
What are the international agreements to promote sustainable fishing?
1) Fishing quotas based on estimates of sizes of fish stocks
2) Exclusion zones preventing fishing
3) Restricting mesh sizes of nets - younger fish escape
4) Return young fish to sea
5) reduction in fleet size
6) No fishing in breeding season
7) Fishing non-traditional varieties
8) encourage consumers/supermarkets to buy/stock Ethically supplied fish
What are the issues associated with fish farming?
1) Densely stocked fish are easily diseased, which can pass to wild fish
2) overuse of antibiotics -> resistance
3) Pesticides control fish parasites, and harm marine invertabrae
4) extra ammonia and faeces excreted increases NO3- conc, and causes eutrophication
What are Biofuels?
fuels with BIOLOGICAL ORIGINS
Give examples of biofuels:
1) wood
2) ethanol
3) Plant oils
4) methane
what are the advantages of Biofuels
1) almost CARBON NEUTRAL - as the plant grows, it adsorbs CO2 via PHOTOSYNTHESIS, and releases CO2 when combusted
What are the Disadvantages of biofuels?
1) Not entirely carbon neutral - if ENERGY IS REQUIRED TO PROCESS the plant to produce the fuel
2) land is used to grow biofuel plants means that HABITATS ARE LOST leading to a REDUCTION IN BIODIVERSITY
What is Eutrophication?
The process of REDUCTION IN BIODIVERSITY within a habitat due to excess NO3- and PO4- IONS
What do plants use NO3- and PO4- ions for?
Synthesis of:
1) Nucleic acids
2) Phospholipids
3) Amino acids
what is the result when nitrate and phosphate ions are in a high concentration within a habitat?
RAPID PLANT GROWTH
What are the 2 types of eutrophication?
1) Terrestrial
2) Aquatic
Describe terrestrial eutrophication
1) Use of fertilisers
2) rapid growth of grasses
3) COMPETITION FOR LIGHT/WATER
4) Reduction in biodiversity
what is aquatic eutrophication?
Build up of NO3- and PO4- salts in waterbodies, causing a reduction in biodiversity
How do the nitrates get into the water body from the land?
The nitrates are highly soluble and are easily leached from soil and washed into rivers
Describe the process of aquatic Eutrophication?
1) Surface algae growth is promoted - algal bloom
2) water becomes green, restricting light from reaching the bottom of the water body
3) the plants are unable to photosynthesise and die
4) Short lived algae die
5) dead matter decomposed by aerobic saphrophytic bacteria
6) Water becomes deoxygenated - high biochemical oxygen demand
7) fish and other aerobically respiring animals die
8) Animal species diversity decreases
