Topic 4 - Biodiversity Flashcards
What is biodiversity?
Refers to the variety of organisms in an area.
What are the three levels of biodiversity?
1) Ecosystem diversity - the number of habitats.
2) Species diversity - the number of species and the number of individuals of each species.
3) Genetic diversity - the variation in alleles within a population of a species.
What is a habitat?
The place where a species lives within an ecosystem
What is a community?
The living organisms of all species found in a particular ecosystem at a particular time
What is an ecosystem?
A relatively self-contained community of interacting organisms, and their environment
What is species richness?
The total number of individuals of each species in a community.
How is species richness quantified?
By taking random samples and counting the species present.
What does a high species richness indicate?
A higher species richness indicates greater diversity
What is species evenness?
A comparison of the numbers of individuals in each species in a community
How is species evenness measured?
Measured by taking samples and counting individuals of each species.
What does a more even abundance indicate?
More even abundance means higher species evenness and diversity.
What is the equation for diversity index?
d = N(N-1) / ∑n(n-1)
What are some impacts of a growing human population on biodiversity?
1) Deforestation for development destroys habitats and reduces ecosystem diversity.
2) Overuse of resources causes certain species to decline or go extinct, reducing genetic and species diversity.
3) Urban sprawl isolates wildlife populations, limiting breeding and decreasing genetic diversity.
4) Pollution kills species directly and harms habitats long term.
What are some agricultural practices that reduce biodiversity?
1) Monocultures
2) Converting woodland and hedgerows into fields
3) Filling in ponds, draining marshes, overgrazing of land
4) Removing weeds with herbicides
5) Using pesticides to kill crop pests
6) Using inorganic fertilisers
What are some methods that can help balance conservation and agriculture?
1) Maintaining hedgerows
2) Reducing pesticide and herbicide use
3) Using organic fertilisers
4) Using crop rotation
What are the effects of climate change on biodiversity?
1) Different regions experience changes in temperature and rainfall, and most species are adapted to specific climates.
2) Changed conditions will make certain areas more or less habitable in general.
2) Suitable habitats for some species will expand or contract e.g. melting polar ice caps removes a habitat for all polar animals.
3) Changing climate conditions may influence species distribution and migration.
4) Slow-moving species may become extinct if the change is too rapid or severe.
5) If conditions in general become warmer, tropical diseases will be more likely to spread.
6) Rising sea levels may lead to more frequent flooding of terrestrial habitats in low-lying land.
