Chapter 11 - Biodiversity Flashcards
What are the 3 different levels of biodiversity
Habitat diversity
Species diversity (species richness, species eveness)
Genetic diversity
What is habitat biodiversity
The number of different habitats in an area
What is species diversity
Species richness
The number of different species in an area
Species eveness
The number of individuals present in each species in an area
what is Genetic diversity
The variation of alleles within a species
Species definition
Group of similar organisms that are able to reproduce to give fertile offsprings
Habitat définition
Area inhibited by living organisms (species)
Biodiversity definition
The variety of living organisms in an area
What can sampling be used for
MEASURE BIODIVERSITY
To estimate the number of organisms in an area
To estimate the abundance and distribution of an organism
To measure a particular characteristic of an organism
What is random sampling and why
Selecting individuals by chance
This avoids bias
More representative of the actual area
Examples of random sampling
Dividing a field into a grid
Using random number generator to coordinates
What is non random sampling
Sample is not chosen at random
Three main non-random sampling techniques
Stratified
Systematic
Opportunistic
What is the systematic technique
Example
Samples taken at fixed intervals
Quadrants placed along a transect at fixed intervals
What is stratified sampling
Example
Different areas in the habitat are identified and sampled separately
Population divided into subgroups based on characteristics
Sample is taken from each strata, proportional to its size
What is opportunistic sampling
Example
The area is chosen by the leader
Simple
Organisms are conveniently available
Safe
Why is sampling never truly reliable
Why isn’t it truly representative of the organisms present
Bias
- more interesting areas may be chosen
- reduces by random sampling
Chance
- reduce by doing a larger sample
What are 5 Techniques used to collect animals for study
5
Pooter Sweep nets Pitfall traps Tree beating Kick sampling
What is a pooter
Used to catch
And how
Small insects
Sucking on mouthpiece to draw insects up into holding chamber via inlet tube
What is a sweep net
Used to catch
And how
Flying insects
Sweep the net and catch them
What is tree beating
Used to catch
And how
Invertebrates living in trees
White cloth stretched under tree to catch invertebrates
Tree is kicked and shaken
What is a pitfall trap
Used to catch
And how
Small crawling invertebrates
Hole dug in ground with roof placed on top
Invertebrates fall into hole
What is kick sampling
Used to catch
And how
Organisms living in water
Net held downstream
River bank kicked to disturb substrate
Organisms caught in net
What is a tullgren funnel
Used to catch
And how
Used to collect insects from soil
Sample placed in sieve over a funnel
Light above dries and warms the soil
Causing animals to move downwards and fall through sieve into funnel
Dish contains ethanol to stop escape
What are quadrats used for
Name the 2 type of quadrats
Used to sample plants
To pinpoint an area that should be sampled
Sample small slow animals
Point quadrat
Frame quadrat
What is a point quadrat
Frame with horizontal bar containing holes at intervals
Pins pushed into holes and soil
Species of plant that touches the pins is recorded
what is a Frame quadrat
Square frame divided into grids
Count type and number of species in each section
3 different ways to use a quadrat
Measuring by:
Density:
- if plants can be seen clearly
- count number of them
Frequency
- hard to count
- count number of squares species is present
- percentage
Percentage cover
- abundant
- estimate by eye percentage of quadrat it covers
How to estimate plant population size
Quadrat
Take many samples
Calculate mean of individual results
Find total population of organism in area
Multiply by total area
Estimating animal population
Compare the number of marked and unmarked organisms
More marked = lower population
What does Simpson’s index of diversity do
Measures biodiversity
Takes into account species richness and evenness
Value between 0-1
No diversity - infinite diversity
Simpson’s index of diversity
Formula
1 - sum of (species evenness / total number of organisms)2
Do for each species
Add together
Minus from 1
Why is genetic biodiversity important
A variety of alleles means species can adapt to changes in their environment
Likely to be an organism with an advantageous gene
Enabling them to survive changing environments
Not become extinct
Share the advantageous gene
How to increase genetic biodiversity
Mutations
Create new alleles
Gene flow
Alleles transferred between different populations
Decreasing genetic biodiversity
Selective breeding
- only few individuals allowed to breed for advantageous gene
Captive breeding
- few animals available for breeding
- less alleles shared
Artificial cloning
Natural selection
- disadvantageous alleles die
Genetic bottleneck
- large number die before reproducing
Founder effect
- few individuals colonisé to new area
Naturally disappear
When are biodiversity levels low
Zoos = captive breeding
Rare breeds
Pedigree animals
What are rare and pedigree animals
Rare
- animal not used in large scale farming
Pedigree
- been bred purely from animals of the same breed
What is polymorphism
Describes a locus with 2 or more alleles
Formula used to measure genetic diversity
Proportion of polymorphic gene loci =
Number of polymorphic gene locis / total number of locis
3 factors that affect global biodiversity
Human growth
Agriculture
Climate change
How does human population growth affect biodiversity
Habitat loss from development
- decreases habitat diversity - decreases species diversity
- isolate species so they can’t interbreed = decreases genetic diversity
Over exploitation - deforestation
- resources used up faster than can be replenished
- decreases habitat diversity - decreases species diversity
Pollution
- decreases species
How does agriculture decrease biodiversity
Monoculture
- decreases genetic diversity
- species diversity
Clearing land
- decreases habitat diversity
- decreases plant species
How does climate change affect biodiversity
- areas will get hotter, colder, drier, wetter
- causes low areas of biodiversity to struggle = decreases species
- migration to other areas = decreases species
- new plants may grow = increase species
What are the ecological reason for maintains biodiversity
To protect species including keystone species
To maintain genetic diversity
Why is protecting species and keystone species important for ecological reasons
Organisms in a ecosystem are interdependent
- disruption of food chains
- disruptions of nutrient cycle - decomposers recycle nutrients into solid, grow plants, animals feed off of
What are keystone species
Species which many of the other species depend on, whom without the ecosystem would change
Predators
Modifiers - maintaining environment needed for ecosystem (beavers-dams)
Hosts - plants that provide a particular environment
Why is maintain genetic resources important for ecological reasons
Provide us with everyday products (food,drugs,clothes,medicine,fuels)
Allow us to adapt to changes in environment
- to genetically engineer drought resistant crops
Why is reducing soil depletion important for economic reasons
Reduce soil depletion by
Rotating crops with other crops so that the nutrients and organic matters can be replaced = increases biodiversity
Soil depletion costs
- buying fertilisers
- lower yields
Why is protecting biodiversity important for aesthetic reasons
Pleasant to look at
Beautiful landscapes
Attract more visitors
What is insitu conservation
On site conservation
Methods of insitu conservation
National parks, marine conservation zones = established areas
- stopping urban development, hunting, farming
Controlling or prevent the introduction of threading species
Giving legal protection to endangered species
Protecting habitats - controlling water levels
Promoting species - protecting food, nesting sites
What is exsitu conservation
Off site conservation
Advantages of insitu conservation
Conserved in their natural habitat
Less disruptive than removing removing from habitat
Natural and cultural heritage protected
Disadvantages of insitu
Genetic diversity may have already been decreased
Diseases and inter specific threats still present
Poachers may cause damage
Methods of exsitu conservation
Relocating to safer area
Breeding in captivity than releasing into nature
Botanic gardens
Seed banks
Advantages of exsitu conservation
- protect individual animals in a controlled environment
- completely protected from predators poaching
- genetic diversity can be managed
- used for education
Disadvantages of exsitu
Limited genetic diversity Living outside of natural environment Expensive Only small number of animals Don’t adapt to new environment Catch diseases from humans
International agreements to protect species and habitats
Rio convention of biological diversity (CBD)
CITES agreement
What does the Rio convention of biological diversity (CBD) do
Aims to use animal and plant resources in a sustainable way
Provides guidance to governments on how to conserve biodiversity
Made an international law that biodiversity is everyone’s responsibility
What does the CITES agreement do
Increases international cooperation in regulating trade
Illegal to kill an endangered species
Limiting trade through licensing
Illegal to trade parts from endangered species
Raise awareness = education
Local conservation agreements
The countryside stewardship scheme (CSS)
What does The countryside stewardship scheme (CSS) do
Conserve wildlife and biodiversity
Promotes specific management techniques to landowners
10 year agreements to pay landowners that follow these management techniques
- increases habit and species diversity
