Biodiversity Flashcards
Different levels at which biodiversity can be measured
Habitat biodiversity
Habitat biodiversity
Number of different habitats found within an area
Species biodiversity
Made of species richness and evenness
Species richness
Number of different species living in a particular area
Species evenness
Comparison of the number of individuals of each species living in a community
Community
All the populations of living organisms in a particular habitat
Genetic biodiversity
Variety of genes that make up a species
Sampling
Taking measurements of a limited number of individual organisms present in a particular area
Uses of sampling
To estimate the number of organisms in an organism
Types of sampling
Random
Random sampling
Selecting individuals by chance
How to carry out a random sample
Make grid with tape measures
Types of non-random sampling
Opportunistic
Opportunistic sampling
Using organisms that are readily available
Weakest form of non-random sampling
Opportunistic
Why is opportunistic sampling the weakest form of non-random sampling?
Not representative
Stratified sampling
Dividing a population into strata based on a characteristic
Systematic sampling
Identifying different areas within an overall habitat which are then sampled separately (Transects)
Line transect
Marking a line along the ground between the poles and taking samples at specific points
Belt transect
Two parallel lines marked
Why is a sample never truly representative?
Sampling bias
How to reduce sampling bias
Random sampling
How to reduce effect of chance
Large sample size
Sampling methods
Pooters
Types of quadrats
Point
Point quadrats
Frame containing a horizontal bar
Frame quadrats
Square frame divided into grid of equal sections
How to measure species richness
Use sampling method
Different things you can measure with frame quadrats
Density
How to do capture-mark-release-recapture
Capture as many individuals of a species as possible
How to measure species evenness using capture-mark-release-recapture
Compare the total number if each organism present
Simpson’s Index of Biodiversity
Measure of biodiversity that takes species richness and evenness into account
Formula for Simpson’s Index of Biodiversity
1- (Sum of total number of organisms of a particular species/ Sum of total number of organisms of all species)^2
What a low biodiversity index means
Few successful species
What a high biodiversity index means
Large number of successful species
Equation for proportion of polymorphic gene loci
Proportion of polymorphic gene loci = Number of polymorphic gene loci/ Total number of loci
Polymorphic genes
Genes with more than one allele
Suitable populations for measuring genetic biodiversity
Zoos
Factors that affect genetic biodiversity
Mutations
Gene flow
When an individual migrates from one population and breeds with a member of another population so alleles are transferred between two populations
How genetic biodiversity can decrease
Selective breeding
Genetic bottleneck
When few individuals within a population survive an event
Founder effect
Where a small number of individuals create a new colony which is geographically isolated from the original
Genetic drift
Random nature of alleles being passed on from parents to their offspring
Factors affecting biodiversity
Human population growth
Effect of deforestation on biodiversity
Reduces number of trees present
Effect of agriculture on biodiversity
Deforestation
Effect of climate change on biodiversity
Melting of polar ice caps leads to extinction of species in those areas
Aesthetic reasons for maintaining biodiversity
Enriching lives (I’m not kidding
Economic reasons for maintaining biodiversity
Soil erosion and desertification as a result of deforestation
Ecological reasons for maintaining biodiversity
Interdependence of species
Keystone species
Species that play a key role in maintaining the structure of an ecological community which is large relative to their abundance
Conservation
Preservation and careful management of the environment and of natural resources
Advantages if in situ conservation
Maintains genetic diversity
Active management techniques in wildlife reserves
Controlled grazing to allow species time to recover
Succession
When early colonising species of an area are replaced until a stable mature population is achieved
Methods of in situ conservation
Wildlife reserves
Role of marine conservation zones
To create areas of refuge where populations can build up
Methods of ex situ conservation
Botanic gardens
How to get seeds ready for storage in seed banks
Dried
How to ensure that genetic diversity is maintained in a captive breeding programme
Catalogue of data produced to ensure matches as different as possible
Issues on release after captive breeding programmes
Loss of resistance to local diseases
3 agreements made in the Rio Convention
Convention on Biological Diversity
Convention on Biological Diversity
Countries must develop national strategies for sustainable development to ensure biodiversity
United Nations Framework Convention on Climate Change
Requirement to take steps to stabilise greenhouse gas concentrations in the atmosphere
United Nations Convention to Combat Desertification
Preventing the transformation of fertile land into desert
Countryside Stewardship Scheme
Offering financial incentives for farmers to sustain diversity of a landscape
Why does higher genetic biodiversity increase a species’ chance of long term survival?
Greater genetic variation
Advantages to using sensors (pH probes
temperature probes) to measure abiotic factors
Different things that can be measured to measure species evenness
Percentage cover
Advantages of measuring population density to measure species evenness
Accurate
Disadvantages of measuring population density to measure species evenness
Time consuming
Advantages of measuring frequency to measure species evenness
Rapid
Disadvantages of measuring frequency to measure species evenness
Approximate result
Advantages of measuring percentage cover to measure species evenness
Lots of data collected quickly
Disadvantages of measuring percentage cover to measure species evenness
Least precise method
Why is species evenness important in measuring biodiversity?
More quantitative than species richness
Why is it likely that our estimates of species richness are underestimates?
Not all areas explored
CITES
Convention on International Trade in Endangered Species
Aims of CITES
Monitor trade in endangered species
Aim of Rio Convention in Biological Diversity
Sustainable use of organisms
How to ensure the success of release programmes after captive breeding
Healthy before release
Why are seeds dried before storage?
Stops enzymes working
Why is it better to store seeds than adult plants?
Can be collected without damaging plants