4.2.1 Biodiversity COMPLETE Flashcards
DEFINITION- Species
A group of organisms that can breed together and produce fertile offspring
DEFINITION- Organism
An individual
DEFINITION- Population
All individuals of the same species
DEFINITION- Community
All different species that live in an area
DEFINITION- Habitat
Where species live
DEFINITION- Ecosystem
A community and its non living (Abiotic) environment make an ecosystem
DEFINITION- Niche
Ecological role the animal plays in the environment
DEFINITION- Habitat Diversity
The number of different habits found within an area
DEFINITION- Species Diversity
A measure of diversity within the community, takes into account both species richness and species evenness
DEFINITION- Genetic Diversity
Variety of genes that make up a species
DEFINITION- Species Richness
No of species living in a particular area
DEFINITION- Species Evenness
The number of each species living in a community
Why take samples
- More cost effective
- Less time consuming
DEFINITION- Sampling
To measure diversity of a habitat you need to identify and observe all the individuals of all the species in the area, instead you select a small portion of the habitat and study that carefully.
Two estimates made using information from samples
- Estimate the number of organisms in an area
2. Gain an estimated measurement of a particular characteristic of an organism
Random Sampling
Ensures data is not biased but may not cover all areas of a habitat equally. Species with a low presence may be missed leading to underestimates of biodiversity
Opportunistic Sampling
Uses the organisms that are conveniently available. Its easy and quick but data may be biased.
Stratified Sampling
Divides population into sub groups based on particular characteristics, random samples are then then from it.
Ensures that no species are underestimated but may lead to overestimation of biodiversity.
Systematic Sampling
Different areas in an overall habitat are identified and then sampled separately, Belt and Line transects.
Useful when habitat shows a clear gradient however only species on the line are recorded so some species may be underestimated.
Ensuring Reliability
Repeat and test if results are similar
Avoid sampling bias (eliminate human involvement)
Minimise impact of chance (use large sample)
Sampling plants
Frame quadrat- Gives more accurate and consistent estimates of % cover
Point quadrat- Allows a choice of size based on the habitat
Quadrat Size
Pick a quadrat that enables you to count 80-100% of the species inside.
What plant sampling allows you to find out
- Species Richness
- Species Frequency
- Species Density
- Percentage cover
- Abundance (ACFOR)
Sampling Animals
- Sweep Netting, insects
- Pooter, breath in the smalll insects
- Longworth Traps, small mammals
- Pitfall traps, walking invertebrates
- Tullgren Funnel, invertebrates in soil
- Tree beating, shake tree so insects fall
- Kick sampling, disturb the stream bed to catch organisms in nets
- Light Trap, attracts moths
Mark, release, recapture equation
(Number in first sample x Number in second sample) / Number of marked animals in second sample
Abiotic Factors and how they’re measured
Wind speed- Anemometer (ms-1) Light intensity- Lux Meter (lx) Humidity- Humidity Sensor (mgdm-3) pH- pH probe (pH) Temperature- Temp Probe (celcius) O2 content in water- Dissolved O2 probe (mgdm-3)
Why species with greater genetic diversity are less likely to become extinct
- Change in environment/ Selection pressures
- Greater variety of alleles
- More chance that some individuals will have advantageous allele
- These individuals survive and reproduce passing on the advantageous alleles.
Factors affecting biodiversity
Mutation Gene Flow Natural Selection Genetic bottlenecks Founder effect Genetic Drift Selective breeding Captive breeding Rare breeds Artificial cloning
Monomorphic genes
A single allele exists for this gene
Polymorphic genes
More than one allele for each gene, e.g. with blood group
DEFINITION- Extinction
Death of the last individual of a species
DEFINITION- Mass Extinction
Sharp decrease in diversity and abundance of macroscopic life
Problems with Extinction
- Loss of potential solutions i.e. for medicines
- Disrupts habitat
- Economic impact
- Food chains disrupted
Human activity that is reducing biodiversity
- Deforestation
- Agriculture
- Invasive species
- Over harvesting
- Pollution
- Climate change
Ecological Reasons to Conserve
Some species play a key role in maintaining the structure of an ecological community, known as keystone species. Their effect on the environment is disproportionate to their abundance
Economical Reasons to Conserve
Maintaining biodiversity improves long term productivity, undiscovered species may have potential economic importance i.e. with medicine.
Species provide a gene pool which may be useful to humans in the future, thus providing profits
Aesthetic Reasons to conserve
Provides inspiration for artists and writers, its part of our culture. The natural environment helps people recover form stress and injury
Keystone Species
Have a disproportionately large effect on their environment, relative to their abundance. Conservation of them helps stabilise entire communities.
e.g. crocodiles
Humans role in increasing biodiversity
- Farming, planting of hedgerows
- Hay meadows
- Forest management (i.e. pollarding)
- Grazing by livestock
DEFINITION- Conservation
The careful management of the ecosystem to increase the organisms chance of survival, allowing organisms to reproduce.
In Situ conservation and Considerations
Conservation in its normal habitat
Must consider the representation of species and what the prevailing conditions are. If the area is large enough for long term survival. Representation of each species.
Advantages of in situ Conservation
- Plants and animals remain in natural habitat so preserves independence.
- Permanently protects biodiversity and ecosystems
- Facilitates scientific research
- Protects elements of cultural heritage.
Problems with in situ Conservation
- Endangered habitats may be fragmented and not offer long term survival
- Attracts poachers
- Conflicts with local people can arise if animals raid crops
- Tourists leave litter
Active management of in situ conservation
- Restrictions of human access
- Controlling poaching
- Feeding animals
- Removing invasive species
Ex situ conservation
Conserving endangered species with activities that take place outside normal habitat
Advantages of ex situ conservation
- Organisms are protected from predation and poaching
- Medical assistance given if required
- Selective breeding and genetic monitoring
Problems with ex situ conservation
- Expensive
- Behaviour is altered so they may fail to breed
- Unsuccessfully be reintroduced to the wild- can’t hunt
- Gene pool is reduced
- Interbreeding
How ex situ problems are overcome
- International catalogue of genetic drift info
- Matings are arranged to maximise genetic diversity
- Artificial insemination embryo transfer, allow genetic lines to be introduced without transporting animals
Advantages to seed banks
- Large numbers of seeds can be collected with little disturbance to ecosystem
- Plants can breed asexually
- Seeds can be stored and germinated in protected surroundings
Disadvantages to seed banks
- Collection of seed banks will cause some disturbance
- Lack of genetic diversity in both sample collecting and in asexual reproduction
- Lack of viability of stored seeds
Seed bank conditions
Dry, Dark, -20˙c
International Cooperations
IUCN- publishes the red list
CBD- aim to conserve bio diversity, share genetic resources and scientific knowledge
CITES- Convention in the trade of endangered species ,so trade doesn’t effect wild population
Local Agreements to maintain biodiversity
Countryside Stewardship scheme- government payments to farmers who enhance and conserve the English landscape
