Biodiversity Flashcards
(31 cards)
Biodiversity ~ what it means & the different types
BIODIVERSITY ~ the variety of living organisms in a region.
3 types of biodiversity:
- Habitat/ecosystem
- Species
- Genetic
HABITAT/ECOSYSTEM Biodiversity
All of the different habitats that we find in a an area.
EXAMPLES:
- Wetlands
- Meadows
- Sand dunes
- Streams
- A place with a RICH habitat biodiversity, will support a wide range of plants, animal, fungi & microorganisms
SPECIES biodiversity
Tells us about the species living in a certain area
SPECIES RICHNESS ~ counts the number of different species present
SPECIES EVENESS ~ compares how many individuals of each species there are in a community.
GENETIC biodiversity
Considers the variety of GENES and ALLELES within a species.
- All individuals of a species have the SAME genes
MONOMORPHIC GENES ~ only one version
POLYMORPHIC GENES ~ have different versions of genes called ALLELES
- A species with a RICH genetic biodiversity can better adapt to ENVIRONMENTAL CHANGE.
Quantifying the level of genetic biodiversity
Proportion of polymorphic gene loci =
number of polymorphic gene loci / total number of loci
GENE LOCUS ~ the position of a gene on a chromosome (plural is loci)
Stable ecosystem
Where the NUMBER of species and the POPULATION SIZES of these species, rarely change
Simpsons Index of Diversity ~ with steps
Used to determine the SPECIES BIODIVERSITY of an area:
D = 1- sum (n/N)^2
n = total number of organism of a particular species
N = total number of organisms of all species
STEPS:
- ADD all the organisms of all the different species to find the total number of organisms (N)
- DIVIDE the number of each species by the total
- SQUARE each value
- ADD together these numbers
- SUBTRACT this total from 1
Community
The POPULATION of living organisms in a HABITAT.
RANDOM sampling
- the area we take samples from are selected by using RANDOM NUMBERS
- Determine the COORDINATES on a map
ADVANTAGES:
- The area is NOT chosen by a human ~ reduces the chance of sampling BIAS
- Reduces the effect of CHANCE
- Minimise ERRORS in obtaining measurements
DISADVANTAGES:
- May not cover all areas of the habitat equally
- Species with a low presence may be missed
Non-random sampling ~ OPPORTUNISTIC
- Scientists select areas that are readily available
ADVANTAGES:
- Easier & quicker
DISADVANTAGES:
- May not be representative ~ samples are UNRELIABLE
- Leads to OVER ESTIMATION
- Attracted to more VIBRANT species
Non-random sampling~ STRATIFIED
- Population is divided into SUBGROUPS or STRATA
- Take RANDOM samplings from each of these subgroups
ADVANTAGES:
- Ensures all areas are sampled
- Species are less likely to be missed
DISADVANTAGES:
- Lead to overrepresentation
Non-random sampling ~ SYSTEMATIC
- Used when there is a gradual change in a habitat from one place to another
Changes could be either:
- abundance of organisms
- features of the organisms
LINE TRANSECT ~ measuring tape placed across habitat , any organism touching tape is samples
BELT TRANSECT ~ place two parallel tapes across the habitat, any organism found between the two tapes are sampled
INTERRUPTED BELT TRANSECT ~ sample organisms at regular intervals along the transect
Why should humans not choose the sample area?
If humans chose the area to study they may select an area:
- easier to reach
- more organisms
- These areas are NOT REPRESENTATIVE of the whole habitat
- REDUCES the RELIABILITY
Advantages & disadvantages (how to reduce this) of sampling
ADVANTAGES:
- Gives an estimate of the population size ~ abundance of the organism
- Representative
DISADVANTAGES:
- Issue of chance
REDUCE THIS:
- Sample a very large number of organisms
- More likely the measurements are representative of the whole population
- Increases the reliability of the sample
Sampling Animals 1
- Sweeping net
- Pitfall trap
SWEEPING NET :
- Swept over the plants multiple times
- Traps any insects present
POOTER:
- Consists of a container with two tubes
- The TRAPPING tube is placed near insect
- The MOUTHPIECE tube is placed in our
mouth & we gently INHALE - The insect is sucked into the container
- CLOTH prevents insects from entering mouth
Sampling Animals 2
- Pitfall trap
- Light trap
- Quadrat
PITFALL TRAP:
- Used for ground level animals
- Consists of a container sunk into the
ground
- Cover prevents any rainwater from entering
LIGHT TRAP:
- Used to sample flying insects at night
- UV light attracts insects
- Collecting vessel under the light contains ETHANOL:
- Used instead of water as evaporates quickly, so organism can fly shortly afterwards
QUADRAT:
- Used to sample slowing moving or static animals
- Placed on the ground and any animals within the quadrat are sampled
Sampling Plants
QUADRAT:
- Count the actual number of plant species within the quadrat ~ Density per m^2
MOSS & GRASS:
- More difficult to count
- Count how many small squares within the quadrat contain the plant
- Record as a % frequency
PERCENTAGE COVER:
- Very quick but least accurate
- Increase reliability ~ place quadrat in
multiple positions and calculate a mean
POINT QUADRAT:
- wooden bar with holes in it
- Place metal pins in each hole
- Any plant species touching the pins are sampled
- Unable to sample plants taller than wooden bar
IN SITU conservation & examples
Conservation that takes place in the organism’s natural habitat.
WILDLIFE RESERVES:
- Areas with special measures put in place to protect the organism.
Examples:
- Restriction on human access
- Hunting & poaching prohibited
MARINE CONSERVATION ZONES:
- Tourism, fishing & extraction of oil and gas are controlled
- Restricted movement of ships
IN SITU ~ advantages & disadvantages
ADVANTAGES:
- Plants and animals are conserved in their natural environment
- Allows management of these area to ensure that ecological integrity is maintained
- Facilitates scientific research
DISADVANTAGES:
- The population may already have lost much of its genetic diversity
- These areas can act as a ‘honeypot’ to poachers & ecotourists
EX SITU conservation & examples
Conservation of organism’s outside of their natural habitat.
ZOOS:
- Captive breeding programmes ~ breeding
endangered species
- INBREEDING ~ reduced by moving animals between zoos to breed
BOTANIC GARDENS:
- Rare plant species are cultivated
- Funding is difficult
- Plants bred ASEXUALLY are genetically identical ~ limits genetic diversity
SEED BANKS:
- The seeds of rare plant species are stored here
- Dried seeds are kept at cold temperatures to preserve them
- Can be stored in huge numbers without occupying too much space
EX SITU ~ Advantages & Disadvantages
ADVANTAGES:
- Health of the organism can be monitored
- Selective breeding can be carried out to increase genetic diversity
- Conservation sites can be used as attraction sites to raise funds for further conservation
DISADVANTAGES:
- Organisms can be exposed to new diseases
- Correct environmental conditions for survival may be difficult to achieve
- Nutritional issues can be difficult to manage
INTERNATIONAL AGREEMENTS ~ Conservation
CITES ~ Conservation On International Trade In Endangered Species:
- Regulate trade in endangered species
- Prohibit trade in wild plants
- Allow trade in propagated plants
- Ensure trade does not endanger wild populations
RIO CONVENTION ON BIOLOGICAL DIVERSITY:
- Sustainable use of organisms, habitats & ecosystems
- Share genetic resources
- Share scientific knowledge
- Promotes ex situ conservation
LOCAL AGREEMENTS ~ Conservation
COUNTRY SIDE STEWARDSHIP SCHEME ~ 1991:
- Encouraged farmers to preserve wildlife and habitats
- Enhance the natural beauty & diversity of the countryside
- Provided grants to maintain hedgerows an dry-stone walls
ENVIRONMENTAL STEWARDSHIP SCHEME ~ replaced CSS in 2005
Factors affecting biodiversity ~ MODERN FARMING METHODS
FARMS:
- Support large populations of a very small number of species
MONOCULTURE:
- Fields with one type of crop
- Herbicides & pesticides kill unwanted plants and animals
HEDGEROWS:
- Contain a rich diversity of plants and animals
- Dug up to make harvesting more efficient
DEFORESTATION:
Provide ~
- land for farming
- wood for construction
- land for cities & roads
