CHAPTER 11 - BIODIVERSITY Flashcards
What is biodiversity
The variety of living organisms present in an area
All species are interconnected. What does that mean
They depend on one another, and any impact on one could have impacts on another
What is an example of interconnectedness of species
Trees provide a home for animals
Animals eat plants
Which need fertile soil to grow
Fungi and microorganisms help decompose dead plants and animals, returning nutrients to the soil
What type of regions have high biodiversity
Tropical moist regions (warm all year round)
What type of regions have low biodiversity
Either very cold areas (Arctic) or very dry areas (deserts)
How does measuring biodiversity play an important role in conservation
Informs scientists of the species that are present, thus providing a baseline for the level of biodiversity in an area
The effect of any changes to an environment can then be measured eg. human activity, disease or climate change
What does the Environmental impact assessment measure
The positive and negative effects of a project on the biodiversity of an area, looking at
Habitat biodiversity
Species Biodiversity
Genetic biodiversity
What is habitat biodiversity
The number of different habitats found within an area
What habitats are in the UK
Meadow, woodland, streams and sand dunes - large habitat biodiversity
What are the two components to species biodiversity
Species Richness and Species Evenness
What is species richness
The number of different species living in a particular area
What is species evenness
a comparison of the number of individuals of each species living in a community
What is genetic biodiversity
The variety of genes that make up a species
What can a large genetic biodiversity lead to
Very different characteristics being exhibited within a species
Better adaption to a changing environment and more likely to produce individuals who are resistant to disease
State the difference between species richness and species evenness
Species richness – the number of different species living in a specific area
Species evenness – the number of individuals within the species living in a community
Compare the biodiversity of an arid desert and a temperate coastline
Habitat biodiversity:
desert – low;
coastline – high (1).
Suitable habitat examples given (1).
Species biodiversity:
desert – low; coastline – high
Suggest why greater genetic biodiversity increases a species chances of long-term survival
Greater genetic variation / wider range of alleles
therefore increased likelihood some organisms are suited to a habitat change
some organisms may be suited to different habitats
therefore more areas may be colonised by the species
some individuals will be resistant to a new disease
therefore lower probability of all organisms being killed by the disease
some organisms will be better adapted to avoid new or adapted predators / catch prey
therefore less chance of being eaten / starvation
other suitable example with consequence
What is sampling
Taking measurements of a limited number of individual organisms present in a particular area
What can sampling be used to estimate
The number of organisms in an area without having to count them all
Measure of a particular characteristic
What is the abundance of an organism
The number of individuals present in an area
What are the two key ways in which sampling can be done
Random and non-random
What is random sampling
Individuals are selected by chance, each individual in the population has an equal likelihood of selection
What are the types of non-random sampling
Opportunistic, stratified and systematic
What is opportunistic sampling
Uses organisms that are conveniently available
The weakest form of sampling as it may not be representative of the population
What is stratified sampling
Some populations can be divided into a number of strata (sub-groups) based on a characteristic - eg. males and females
A random sample is then taken from each of these Strata proportional to its site
What is systematic sampling
Different areas within an overall habitat are identified and sampled separately eg. change in plant species as you move inland from the sea
What is systematic sampling carried out using?
A line transect or a belt transect
What is a line transect
Marking a line on the ground between two poles and taking samples at specified points, which can include describing all of the organisms which touch the line or distances of samples from the line
What is a belt transect
Two parallel lines are marked, samples are taken of the area between the two lines
What are the two contentions to reliability
Sampling bias and chance
What is sampling bias
Where the selection process may be biased, either accidentally or deliberately.
eg. choosing to sample a particular area that has more flowers because it looks interesting
Can be reduced by removing human involvement in selecting areas to sample
What is chance (in reliability of sampling)
Where the organisms selected may, by chance, not be representative of the whole population
eg. a sample of 5 worms maybe the 5 longest worms in the habitat
Chance can never be removed but it can be minimised by using a greater sample size