T7 - biodiversity & the effect of human interaction on ecosystems Flashcards
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.
