Biodiversity & the Effect of Human Interaction on Ecosystems Flashcards
All 30 cards in this deck
What is biodiversity?
The variety of all the different species of organisms on Earth, or within an ecosystem.
A great biodiversity ensures the stability of an ecosystem by reducing what?
The dependence of one species on another for food, shelter and the maintenance of the physical environment.
True or false? Biodiversity means the total number of organisms living in an ecosystem.
False. It is the variety of different species, not the number of individuals.
True or false? The future of the human species on Earth relies on us maintaining a good level of biodiversity.
True. Many human activities reduce biodiversity, and measures to stop this have only been taken recently.
What are the steps to work out how many times greater one population value is than another?
e.g. 6.0 billion in 2000 compared with 1.6 billion in 1900
- Divide the later value by the earlier value:
- Answer: (no units given)
Which two changes in humans mean that more resources are used and more waste is produced?
Rapid growth in the human population and an increase in the standard of living.
Name three harmful substances that can cause water pollution.
Sewage, fertiliser and toxic chemicals (e.g. pesticides).
Name two harmful substances that can cause air pollution.
Smoke (particulates) and acidic gases such as sulfur dioxide.
What two things cause pollution on land?
Landfill and toxic chemicals.
True or false? Pollution reduces biodiversity only when it happens in water.
False. Pollution in water, in air or on land kills plants and animals, so biodiversity is reduced.
What are the steps to calculate the mean annual increase in the human population?
e.g. 1.6 billion in 1900 and 2.5 billion in 1950
- Find the increase: billion
- Divide by the number of years:
- billion per year
Name four human activities that reduce the amount of land available for other animals and plants.
Building, quarrying, farming and dumping waste.
Why do humans destroy areas of peat bog?
To produce garden compost, and to provide peat as a fuel.
What effect does the destruction of peat bogs have on biodiversity?
It reduces the area of this habitat, so the variety of plant, animal and microorganism species living there falls.
Which gas is released into the atmosphere when peat decays or is burned?
Carbon dioxide.
True or false? Buying peat-free compost helps to maintain biodiversity.
True. Peat bogs are not dug up, so the habitat and its species are preserved.
Give three reasons for large-scale deforestation in tropical areas.
To provide land for cattle, to provide land for rice fields, and to grow crops for biofuels.
Give two reasons why deforestation increases the amount of carbon dioxide in the atmosphere.
Burning and decay of the trees releases carbon dioxide; fewer trees remain to take in carbon dioxide for photosynthesis.
What effect does large-scale deforestation have on biodiversity?
It reduces it — habitats are destroyed, so species lose their food and shelter and numbers of species fall.
True or false? Replacing rainforest with a field of one crop such as maize takes in just as much carbon dioxide.
False. The crop takes in less carbon dioxide per day and only grows for part of the year.
Which two gases are increasing in the atmosphere and contribute to global warming?
Carbon dioxide and methane.
What effect does melting of polar ice and rising sea levels have on organisms?
Habitats are lost or flooded, so species may die out or have to move, reducing biodiversity.
True or false? Global warming can change the migration patterns of animals such as birds.
True. Warmer temperatures can change when and how far species migrate.
True or false? Global warming only affects species that live in polar regions.
False. It changes habitats, species distribution and migration patterns worldwide.
What is a breeding programme for endangered species?
Breeding a species at risk of extinction in captivity to increase its numbers, then reintroducing individuals to the wild.
Why are field margins and hedgerows reintroduced where farmers grow only one type of crop?
They provide habitats and food for many species, so biodiversity increases.
What is meant by regeneration of a rare habitat?
Restoring a damaged habitat, e.g. by replanting, so that its species can return.
How does recycling resources rather than dumping waste in landfill help biodiversity?
Less land is used for landfill and less pollution is produced, so fewer habitats are destroyed.
True or false? Governments reducing deforestation and carbon dioxide emissions helps to maintain biodiversity.
True. It preserves habitats and limits global warming.
Give one conflicting pressure that can act against maintaining biodiversity.
The need for land or money — e.g. land is wanted for farming or housing, and protection schemes are expensive or cost jobs.