Module 4 Section 2: Biodiversity Flashcards
What are the human population growth factors affecting biodiversity
Habitats loss
Over-exploitation
Urbanisation
Pollution
How does habitat loss affect biodiversity
Human develop destroys habitats which decreases habitat diversity
E.g. deforestation in the Amazon to make way for grazing and agriculture
How does over-exploitation affect biodiversity
A greater demand for resources (such as food, water and energy) means a lot of resources are being used up faster than they’re replenished
E.g. industrial fishing can deplete the populations of certain fish species and may cause extinction
This decreases genetic diversity within populations, as well decreasing species diversity
How does urbanisation affect biodiversity
Growing cities and road developments can isolate species, meaning populations are unable to interbreed and genetic diversity is decreased
How does pollution affect biodiversity
High amounts of pollutants can kill species or destroy habitats which decreases biodiversity
E.g. high levels of fertiliser flowing into a river can lead to a decrease in fish species
What is monoculture
When large areas or land are devoted to a single variety of crop
This is to feed a growing number of people
E.g. palm oil plantations
How does agriculture decrease biodiversity
Habitats are lost as land is cleared to make way for the large field, reducing habitat diversity
Local and naturally occurring plants and animals are seen as weeds and pests, and so are destroyed with pesticides, reducing species diversity
Heritage (traditional) varieties of crops are lost because they don’t make enough money and so are not planted any more, which reduces species diversity
What is climate change
The variation in Earth’s climate e.g. temperature or rainfall patterns
Occurs naturally but current climate change is caused by humans increasing emissions of greenhouse gases (CO2)
How does climate change affect different areas of the world
Some places will get warmer/ colder or wetter/ drier
All of these are likely to affect global biodiversity
How does climate change affect biodiversity
Most species need a particular climate to survive
A change in climate may mean that areas become uninhabitable
This can cause an increase or decrease in the range of some species which can change biodiversity
Some species may be forced to migrate to a more suitable area, causing a change in species distribution
Migrations usually decrease biodiversity in the areas the species migrate from, and increase biodiversity in the areas they migrate to
If there’s no suitable habitat to migrate to, the species is a plant or the change is too fast, the species become extinct
This will decrease biodiversity
How does deforestation reduces biodiversity
Reduces number of trees in an area
If only a specific type of tree is felled, species diversity is reduced
Destroys habitats and reduces number of animal species present in an area by removing food source and home
Animals are forced to migrate to other areas to ensure survival, increases biodiversity or neighbouring areas
Different reasons why maintaining biodiversity is important
Ecological reasons
Economic reasons
Aesthetic reasons
What is an ecosystem
All the biotic and abiotic components living in a particular area
What does an interdependent ecosystem mean
The organisms depend on eachother to survive
If one species is lost, it can have drastic effects on an ecosystem
Examples of effects of losing a component in an interdependent ecosystem
Disruption of food chains:
If primary consumer numbers fall then both secondary and tertiary populations can decline
Disruption of nutrient cycles:
Decomposes improve quality of soil by recycling nutrients, if numbers of decomposes decline it can reduces growth of plants and therefore food availability
What are keystone species
Species in an ecosystem which many other species depend upon
Without them the ecosystem would change drastically
What types species can be keystone species
Often predators which are needed to control prey populations
Can be modifiers which maintain the environment needed for the ecosystem
Can be hosts which are plants that provide a particular environment
Why do we maintain biodiversity for ecological reasons
To protect species
To maintain genetic resources
What are genetic resources
Refer to any material from plants, animals or microorganisms that contain genes that we find valuable
Examples of genetic resources
Can be:
Crops
Plants used for medicine
Microorganisms used in industrial processes
Animals breeds
Why maintain genetic resources
Provide us with a variety of everyday products
Allow us to adapt to changes in the environment
How do genetic resources provide us with a variety of everyday products
Food and drink
Clothing: fibres and fabrics are made from plants and animals
Drugs: from plant compounds
Fuels: organisms are used for renewable fuels (ethanol, biogas), fossil fuels are non renewable so are of economic importance
Other industrial materials: wood, paper, dyes, adhesives, oils, rubbers, pesticides are from plants and animals species
Many of these resources are important to the global economy as they can be traded at global scale
How do genetic resources allow us to adapt to changes in the environment
Climate change may result in some crops failing (possibly due to droughts)
We can use genes from a plant that’s resistant to droughts to genetically engineer a drought resistant crops (if we have such genetic resources to choose from)
Why should we maintain biodiversity for economic reasons
Soil erosion and desertification can occur due to deforestation, it can reduces a country’s ability to grow crops which can lead to economic dependence on other nations
Large scale biodiversity loss results in economically beneficial species becoming extinct before their benefits have been discovered
Monoculture can result in soil depletion (gradual reduction in nutrients from one species of plant being continuously grown) which produces weaker crops, farmers will become dependent on expensive pesticides and fertilisers to fend of insects and microorganisms to maintain productivity
Areas rich in biodiversity provide an attractive environment that people enjoy. These areas can promote tourism which can bring in income
Diverse areas have more potential for manufacturing new products in the future which can be beneficial to humans
Why should we maintain biodiversity for aesthetic reasons
Natural wonder can inspire musicians and writers which can bring pleasure for many others through books and music
Studies show that patients recover more rapidly from stress and injury which exposed to plants and a natural environment
Biodiversity areas can be relaxing and enriching
What is biodiversity
The variety of living organisms in an area
What is a species
A group of similar organisms able to reproduce to give fertile offspring
What is a habitat
The area inhabited by a species
It includes the physical factors, like the soil and temperature range, and the living (biotic) factors, like availability of food or the presence of predators
What does habitat diversity mean
The number of different habitats in an area
E.g. sand dunes, woodland, meadows
What does species diversity mean
The number of different species (species richness) and the abundance of each species (species evenness) in an area
E.g. a woodland could contain many different species of plants, insects and birds
What does genetic diversity mean
The variation of alleles within a species (or population of species
E.g. the variation of alleles within the dog species gives us different breeds
What is species richness
The number of different species in an area
Higher the number of species, greater the species richness