B17.2- Organising an Ecosystem Flashcards
Describe what is biodiversity
Why is biodiversity important?(2)
A great biodiversity?
the variety of different species of organisms on Earth or within an ecosystem.
- High biodiversity is important and it makes sure that ecosystems are stable because different species depend on each other for things like shelter and food. -Different species can help maintain the right physical environment for each other - removing a species could have a damage on other parts of the ecosystem.
- A great biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment.
Why is biodiversity negatively impacted?(5)
1) Humans reduce the amount of land available for other animals and plants by building, quarrying, farming and dumping waste
2) People around the world are demanding a higher standard of living so we use more raw materials eg oils to make plastic but we also use more energy for the manufacturing processes- we take more resources from the environment more and more quickly- using up finite sources and producing more waste
3) Burning of fossil fuels.
4) Deforestation, pesticides- recuing biodiversity.
5) Agriculture- monoculture and only grow 1 thing.
How does managing waste affect biodiversity (3)
- We’re producing more waste including waste chemicals and unless this waste is properly handled, more harmful pollution will be caused. Pollution affects water, land and air and kills plants and animals, reducing biodiversity.
1) Water waste- sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting plants and animals that rely on them for survival. And the chemicals used on lands such as pesticides, herbicides, fertilizers can be washed into the water.
- Untreated sewage or fertilisers can cause eutraphication
- bioaccumulation
2) Land: We use toxic chemicals for farming eg pesticides and herbicides- we also bury nuclear waste underground and we dump a lot of household waste in landfill sites. They can also become part of the food chain as the toxins get into organsims that feed on the plants or live in the soil therefore as the trophic level increases, more and more toxins build up in the organisms and this is known as bioaccumlation and eventually lead to dangerous levels of poisons building up in the top predators.
3) Air: smoke and acidic gases released into the atmosphere can pollute the air eg sulfur dioxide can cause acid rain.
Describe how global warming is caused?
What are the consequences of global warming? (4)
1) Gases in the atmosphere naturally act like an insulating layer and they absorb most of the energy that would normally be radiated out into space and this increases the temp of the planet.
Consequences:
1) higher temp causes seawater to expand and ice to melt, resulting in sea level to rise- lead to flooding in low lying areas, coastal erosion and loss of habitats. HIGH TEMP also means warmer air can hold a higher water content so rainfall pattern can be more extreme.
2) distribution of wild animals and plant species may change as temp increases and the amount of rainfall changes in different areas- some species may become more widely distributed.
3) changes to the migration patterns of animals and also changes in breeding at diff temp= changes in behaviour.
4) biodiversity could be reduced if some species are unable to survive a change in the climate so become extinct.
Why do humans use lands?
-building, quarrying, farming and dumping waste which means less land is avaiable for other organisms and our use of land has a negative impact on the environment such as deforestation, destruction of habitats like peat bogs.
Why is deforestation done (3) and what problems can it cause? (3)
Deforestation causes problems when it’s done on a large are such as cutting down rainforests in tropical areas. Can be done:
- to clear land for faming eg cattle or rice crops to provide more food.
- grow crops from which biofuels based on ethanol can be produced.
Problems:
-Less Co2 taken in- trees ‘lock up’ some of the carbon they absorb during photosynthesis and remove it from atmosophere = more Co2 in environment and more global warming.
- More Co2 in the atmosphere- trees are burnt to clear land and microorganisms feed on bits of dead wood & release Co2-> respiration.
- Less biodiversity: habitats like forests contain a huge number of diff species of plants and animals so when they are destroyed, there is a danger of many species becoming extinct- biodiversity is reduced.
What are peat bogs?
How are peat bogs destroyed and what’s their effect? (3)
1) bogs are areas of lland that are acidic and waterlogged and peat is made of plant material that cannot decay completetly because the conditions are v acidic and lack of oxyg. It decomposes slowly due to anerobic respiration hence why it is slow and low C02 emissions- Co2 is locked within the compound and these are carbon sinks as they store carbon for a long time
- partly rotted plant gradually build up to form peat so carbon is stored in peat instead of being released.
2) Peat bogs are often drained so the area can be used for farmland or the peat is cut and dried to use as a fuel- sold to gardeners as compost- finite source as it’s been destroyed faster than it is being made and it is formed very slowly.
- peat is drained, it comes into contact with air and some microorganisms start to decompose it-> respire= Co2 released into the atmosphere.
- Co2 is also released when peat is burned as a fuel after being harvested.
- Destruction of peat bogs causes destruction of the habitats of some animals, plants and microorganisms that live there hence reduces biodiversity.
What are the 3 ways biodiversity can be explored? What us a genetic bottleneck?
What is an ecological niche and how do humans impact this? (2)
1) Genetics: the variation of alleles within a species and a genetic bottleneck is where populations are hunted and results in a small population which would reproduce genetically similar to each other
TO IMPROVE: move indivs around to increase genetic biodiveristy
2) Species- variety of diff species within an ecosystem.
3) Ecoystem- the variety of habitats
Ecological niche- same diet and habitat eg a fox and a rabbit would live in the same habitat( a meadow) but have diff diets therefore diff ecological niche. Humans introduce competitive animals that disrupt the ecological niche and would outcompete another animal and leave it to become extinct.
What are some environmental changes and why can they be caused.?
Environmental changes such as availability of temp, water and atmospheric gases affect the distribution of species in an ecosystem. These change may be seasonal, geographical or caused by human interaction.
How can we reduce the negative effects of humans on environment and ecosystem? 5
- many concerned citizens and scientists have set up programmes to minimise damage by human activities.
1) Breeding programmes- help prevent endangered species from being extinct and these are when the animals are bred in captivity to make sure the species survive if it dies out in the wild- indivis can sometimes be released into the wild to boost re-establish a population.
2) Programmes to protect and regenerate habitats like mangroves, heathland and coral reefs have started- protecting these habitats help protect the species that live there- preserving the ecosystem and biodiversity in the area.
3) Reintroduce hedgerows and field margins around fields on farms where only a single type of crop grows. Field margins- areas of land around the edges of fields where wild flowers and grasses are left to grow. Hedgerows and field margins provide a habitat for a wider variety of organisms that could survive in a single crop habitat.
4) Gov intoduced regulations and programmes- reduce level of deforestation taking place and the amount of Co2 being released into the atmosphere by businesses- reduce gw
4) People- encouraged to reduce the amount of waste in landfills- reduce amount of land taken over for landfill, leaving ecosystem in place- recycling resources
What are the conflicting pressures that can affect how biodiversity is maintained?(4)
1) Protecting biodiversity costs money- pay farmers a subsidy to reintroduce hedgegrows and field margins to their land- cost money to keep a watch on whether the programmes and regulations designed to maintain biodiversity are being followed- money can be prioritised.
2) Protecting biodiversity may come at a cost to local people’s livelihood- reducing the amount of deforestation benefits but previously employed peeps r left unemployed- affect local economy.
3) Protecting biodiv vs food security- pests are killed to protect crops and livestock so more food can be produced.
4) Development is impo- land is such a high demands that previously untouched land with high biodiversity has to be used for development.
Why is there usually no quaternary consumer?
-so much energy is lost from the food chain at each trophic level so won’t be able to survive
Define food security?
What can threaten food security? (5)
- having enough food to feed a population
Threats:
1) World pop keeps incr alongside birthrates.
2) as diets in develop countr change, the demand for certain foods to be imported from develop countries incre- already scarce food sources become more scarce.
3) Farming can b affected by new pests and pathogens and changes in environmental conditions eg lack of rain- oss of crops and livestok= widespread famine.
4) High input costs of farming- too expensive for people in countri to start or maintain food production- arent enough people producing food to these areas to feed the peeps.
5) conflicts affecting Availiabilty of food and water.
How can food production be made more efficient? (4)
Why can these methods be controversial?(2)
- Limiting the amount of movement of livestock and keeping them in a temp controlled environment reduce energy transfer from livestock to enviro= animal uses less energy moving around and control body temp=more energy avai for growth and hence more food can be produced from same inpit of resp.
- high calorie content food- high protein = incr growth rate.
- fish can be factory farmed in cages so movem is restricted and factory farmed chickens are called battery chickens.
- controlling the temp of the surrounding means animals don’t have to use much biomass in respiration for keeping warm or cooling down and this leaves more biomass for growth
Controversial:
- animals are kept close together-> disease can spread easily
- ethical objections- unnatural, uncomfortable and conditions are cruel
Why is sustainable methods needed for food production?
-so that enough food can be made to feel everyone now and in the future.
Why is important to control fish stock from decreasing and how can we maintain?(3)
-Fish stock in oceans is declining and it’s important to maintain fish stocks at a level where breeding continues or certain species may disappear altogether.
We need to maintain fish stock at a level where the fish continue to breed- sustainable food production and they can be conserved.
Solution:
1) Fishing quotas- limits on th number and size of sish that can be caught in certain areas- prevent certain species from being overfished.
2) net size- diff limits of the mesh size of the fish net- reduce the number of ‘unwanted’ and discarded fish- using bigger mesh size to let unwanted species escape- also means younger fish will slip through the net, allowing them to reach the breeding age( lobster pot)
3) Restrictions on areas- avoid reproductive areas (spawning grounds) and those areas are called marine conservation zones.
