Define the term biodiversity.
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Define the term biodiversity.
Biodiversity is the variety of different species found in a habitat. This includes, e.g. the number of different species, the size of each population and the differences between individuals of a species.
What are the benefits to an ecosystem of having high biodiversity?
The benefits of high biodiversity include:
increased availability of food and shelter
increased resilience to change
True or False?
Low biodiversity increases ecosystem stability.
False.
Low biodiversity decreases ecosystem stability. This is because when fewer species are present a change in one species is more likely to have a significant impact on other species.
How do different species depend on each other?
Different species depend on each other for:
food
shelter
maintenance of the physical environment
True or False?
In an ecosystem with high biodiversity the loss of one food source will result in the loss of all dependent species.
False.
In a biodiverse ecosystem species will have multiple food sources, so the loss of one food source will have minimal effects on dependent species.
Name three human activities that reduce biodiversity.
Human activities that reduce biodiversity include:
producing waste / pollution
global warming
habitat destruction, e.g. deforestation
introduction of invasive species
How does deforestation affect biodiversity?
Deforestation reduces biodiversity by destroying forest habitats that contain high biodiversity.
Why is maintaining biodiversity important for humans?
Maintaining biodiversity is important for humans because we rely on many other species to survive, such as for oxygen production, food crop pollination, and medicine.
What human activities can result in water pollution?
Human activities that result in water pollution are:
release of untreated sewage into waterways
allowing toxic agricultural chemicals, such as fertiliser, to run off fields into waterways
Describe the consequences of untreated sewage runoff into water systems.
Consequences of untreated sewage runoff into water systems include:
aerobic microorganisms use nutrients in sewage to fuel respiration, depleting dissolved oxygen levels in the water and leading to the deaths of aquatic organisms
toxic chemicals in sewage can kill aquatic organisms
dangerous microorganisms can be harmful to human health
Describe an environmental consequence of the release of acidic gases into the air.
Acidic gases, e.g. sulfur dioxide, can combine with water droplets in the air to form acid rain.
What are some effects of acid rain on the environment?
Consequences of acid rain pollution include:
Damage to leaves, buds, flowers and roots of plants
Rivers and lakes can become acidic, resulting in death of aquatic organisms
Minerals can be leached into bodies of water, also killing aquatic organisms
Describe the impact of discarded rubbish on the environment.
Discarded rubbish can impact the environment as follows:
landfill sites may require the destruction of natural habitats
toxic chemicals can spread from waste materials into the soil
non-biodegradable rubbish can remain in the environment for hundreds of years
What is the relationship between pollution and biodiversity?
Pollution kills plants and animals, which can reduce biodiversity.
Which human activities reduce the land available for other species?
Human activities that require increasing land use are:
building
quarrying
farming
disposal of waste
True or False?
Habitat destruction increases biodiversity.
False.
Habitat destruction reduces biodiversity.
What is a peat bog?
A peat bog is an area of land that is waterlogged and acidic. The organic matter in a peat bog is known as peat, and consists of dead plants that have not decayed fully due to low pH and a lack of oxygen.
How do peat bogs store carbon?
Peat bogs store carbon within the tissues of partially decomposed plant matter. Because the conditions are unsuitable for decay this carbon remains locked up in peat.
Name three reasons why peat bogs are being destroyed.
Peat bogs are being destroyed because:
drained peat bogs can provide farming land
peat can be burned as fuel
peat produces fertile compost
How does peat bog destruction affect biodiversity?
Peat bog destruction reduces biodiversity by decreasing available habitat for many species of animals, plants, and microorganisms.
How does the loss of peat bogs increase atmospheric carbon dioxide concentration?
Peat bog loss increases atmospheric carbon dioxide as follows:
peat combustion releases carbon dioxide
destruction of peat bogs, e.g. by draining away water, allows decay to occur, so carbon dioxide is released during decomposition
True or False?
Peat is a renewable energy source.
False.
Peat is a non-renewable energy source due to the long time it takes to form.
Define the term deforestation.
Deforestation is the process of clearing trees, usually on a large scale. This is often done to make way for building or agriculture.
What are two main reasons for deforestation in tropical areas?
Two main reasons for deforestation in tropical areas are to:
provide more land for farming
grow crops for biofuel production
What is a biofuel?
A biofuel is a fuel derived from living matter, such as plant material.
What are the environmental effects of deforestation?
Environmental effects of deforestation include:
extinction of species
soil erosion
leaching
flooding
disruption of the carbon cycle
disruption of the water cycle
True or False?
Deforestation decreases atmospheric carbon dioxide concentration.
False.
Deforestation increases atmospheric carbon dioxide concentration. This is because living trees absorb carbon dioxide during photosynthesis; removal of these trees therefore reduces the rate at which carbon dioxide is removed from the atmosphere.
True or False?
Deforestation only affects plant species.
False.
Deforestation affects both plant and animal species, potentially leading to their extinction.
Describe the greenhouse effect.
The greenhouse effect occurs when radiation from the sun is absorbed by greenhouse gases in the earth's atmosphere. This traps heat and warms the atmosphere.
Name two greenhouse gases.
Two greenhouse gases are:
Carbon dioxide
Methane
(There are other greenhouse gases but these are the two listed in your specification.)
Define the term global warming.
Global warming refers to the long-term increase in the earth's average temperature, primarily due to human activities that increase the levels of greenhouse gases in the atmosphere.
What are some of the consequences of global warming?
Some consequences of global warming include:
increasing ocean temperatures
melting of polar ice caps
rising sea levels
extreme weather events
habitat change / loss
decreases in biodiversity
increased spread of pests and diseases
True or False?
Ocean temperatures are not affected by global warming.
False.
Global warming is increasing ocean temperatures, leading to impacts such as melting polar ice caps, rising sea levels and coral bleaching.
What is meant by the phrase scientific consensus, in the context of global warming?
A scientific consensus, in the context of global warming, describes the fact that almost all scientists agree that global warming is happening and that human activities are largely responsible for the most recent warming
True or False?
Human interactions with ecosystems are always negative.
False.
Humans can have both positive and negative interactions with ecosystems.
Name three programmes that are designed to reduce negative human impacts on ecosystems.
Programmes designed to reduce negative human impacts on ecosystems include:
breeding programmes for endangered species
protection of rare habitats
habitat regeneration
reduction of deforestation
reintroduction of hedgerows and field margins in agriculture
government targets to reduce carbon emissions
waste recycling programmes
What is an endangered species?
Endangered species are plants or animals at risk of extinction.
How can breeding programmes be used to conserve endangered species?
Breeding programmes can be used to increase the reproductive success of endangered species in captivity; this can help to increase their population size and genetic diversity.
What is habitat regeneration?
Habitat regeneration is the process of restoring damaged or destroyed habitats to support native species.
True or False?
Having large field margins and hedgerows reduces biodiversity in agricultural areas.
False.
Reintroduction of field margins and hedgerows in agricultural areas increases biodiversity.
What is a monoculture?
A monoculture is the agricultural practice of growing only one type of crop in a field.
How do field margins and hedgerows benefit biodiversity?
Field margins and hedgerows benefit biodiversity by providing habitats and corridors for wildlife in agricultural areas.
What is the main reason for reducing carbon dioxide emissions?
The main goal of reducing carbon dioxide emissions is to slow climate change, which can negatively impact ecosystems and biodiversity.
How does recycling help biodiversity?
Recycling helps biodiversity by reducing the waste dumped in landfill, which can destroy habitats and cause pollution.