Chapter 11 - Biodiversity Flashcards
Why is biodiversity important?
To maintain a balanced and healthy ecosystem.
All species are interconnected and they rely on one another.
How can biodiversity measured?
Habitat
Species
Genetic
Habitat biodiversity
The greater the habitat biodiversity, the higher species biodiversity.
Tropical countries have the most biodiversity, due to their hot, wet climate.
Species biodiversity
Species Richness
Species Evenness
Species Richness
Number of different species living in an area.
Species Evenness
A comparison of the number of individuals of species living in a community.
Genetic biodiversity
Refers to the variety of genes
Different animals have different alleles, so they have different characteristics.
Greater genetic biodiversity allows a better adaptation to a changing environment, and they are likely to stay resistant to disease.
What are the 5 ways to samples animals
Pooter Sweep nets Pitfall traps Tree beating Kick sampling
What are the 2 quadrats
Point Quadrat and Frame Quadrat.
Explain point quadrat
A frame containing a long pin. Every time it is pushed into the ground, a record of all the plants touched is made.
Explain frame quadrat
A square frame divided up into a grid.
Species richness being sampled
You should use a combination of techniques. Sometimes, scientists use identification keys to help classify animals.
3 ways to use frame quadrats
Density : if individual plants can be seen clearly, this is an absolute measure.
Frequency
% cover
Estimating animal population size
Capture- mark- release - capture.
The greater the mark no. of species, the smaller the population.
How to measure wind speed
anemometer
How to measure o2 content
Dissolved Oxygen probe.
Advantages of sensors
Rapid change can be detected.
Human error whilst reading can be reduced.
Higher degree of precision.
Data is stored and tracked.
What is the equation called to calculate biodiversity
Simpson’s index of biodiversity
Simpson’s index of biodiversity
D = 1 - sum of( n/ N )^2
n: Total no of particular species
N: Total no of organisms of all species.
What do scientists often have to do before they can calculate biodiversity
Estimate the population size.
D is a value…
Between 0 and 1. 1 means more diverse
What is the nature of environment in an area of low biodiversity
Few ecological niches
What is the nature of environment in an area of high biodiversity
Many ecological niches
Adaptation of species in an area of low biodiversity
Very specific adaptation.
Adaptation of species in an area of high biodiversity
Very few adaptations
Effect of change to the environment in an area of low biodiversity
Major effect.
Effect of change to the environment in an area of high biodiversity
Little effect.
What factors affect genetic biodiversity
Mutation
Interbreeding between different populations
(alleles can be exchanges and this is called gene flow)
How can the no. of alleles in a population decrease?
- Selective breeding
- Captive breeding
- Rare breeds
- Artificial cloning
- Natural selection
- Genetic bottlenecks
- Founder effect
- Genetic drift
Explain rare breeds
When selective breeding has been used to make a new breed, but they became not as popular so the population falls.
Explain natural selection
Evolve due to advantageous characteristics
Explain genetic bottlenecks
A change (environmental or disease) that reduces the gene pool.
Explain founder effect
A small number of individuals create their own colony, where there is a small gene pool.
Explain genetic drift
Due to randomness, the frequency of occurrence of an allele can vary.
What is a polymorphic gene
They have more than 1 allele.
Polymorphic equation
Proportion of polymorphic gene loci = no. of polymorphic gene loci / total number of loci
What does loci refer to?
The position of gene on a chromosome.
Increased proportion means…
Increased biodiversity
How can you measure the number of polymorphic genes
Gel electrophoresis is a technique used to separate fragments in DNA, based on size. DNA is cut into small pieces, then placed in a gel. The gel is placed in between 2 oppositely charged electrodes. The faster the DNA travels, the smaller the DNA. It creates a pattern, called a banding pattern, which can be used to compare.
What are the 3 main things that affect biodiversity
Deforestation
Agriculture
Climate change.
How does deforestation affect biodiversity
- Directly reduce the number of trees
- (If only a specific type of tree is removed), it removes biodiversity.
- Reduces animal habitats and food.
- Animals have to migrate.
How does agriculture affect biodiversity
- Deforestation
- Removal of hedgerows
- Pesticides
- Herbicides
- Monoculture
How does climate change affect biodiversity
- Melting of polar ice caps - reduces the habitat of species
- Rising sea levels causes flooding. Saltwater can damage trees.
- Droughts - rise in xerophytes, but still a reduction in biodiversity.
- Insects carry diseases. With changing temperatures, they might change their lifecycle.
What is the one note about climate change and biodiversity
If climate change is slow, then it gives species time to adapt, and it may have a smaller impact on the biodiversity.
What are the reasons for maintaining biodiversity?
Aesthetic
Economic
Ecological
Explain aesthetic reasons for maintaining biodiversity
Patients recover faster
Muse for artists
Relaxation
Explain economic reasons for maintaining biodiversity
- Deforestation causes soil erosion. Can’t be used to grow crops.
- Run out of everything.
- Species extinction (they could have been medically quite useful)
- Continuous monoculture leads to soil depletion. This can create a fragile ecosystem, which is vulnerable to disease.
- High biodiversity protects against natural disasters (so they may have alleles to fight back against diseases)
- Tourism
- Potential for manufacture in the future (eg. medicine)
- Plant varieties are needed for cross-breeding (for disease resistance. and increase crop yield)
Explain ecological reasons for maintaining biodiversity
All organisms are interdependent on others for survival (eg. decomposers)
- Keystone species. Without them, the entire habitat might change.
What is conservation
Preservation and careful management of the environment and of other natural resources.
What are the 2 types of conservation
In situ and ex situ.
What are the 4 types of classifying conservation of animals
Extinct - no organisms
Extinct in the wild - only in captivity
Endangered - In danger of extinction
Vulnerable - a species that is considered likely to become endangered in the near future.
In situ conservation main points
Wildlife resources.
Marine conservation.
Maintains the genetic diversity of species and the evolutionary adaptations that enable species to adapt continually to changing environmental conditions.
Allows endangered species to interact with others, it preserves the independent relationships in a place.
It’s generally cheaper.
Wildlife resources active techniques
Controlled grazing Restricting human access Controlled poaching Feeding animals reintroduction of species Removal of invasive species (that has negative effects on the economy by competing with other species.) Halting succession
What is succession
A natural process in which early colonising species are replaced over time until a stable population is created.
What are the main points for ex situ conservation
Botanic Gardens
Seed banks
Captive breeding programmes
Seed banks
Dried and stored at temperatures of -20 degrees to maintain the ability to still be able to germinate.
Captive breeding programmes
Produce off spring of species in a human- controlled environments to produce a healthy stable population.
Downside of captive breeding
Maintaining genetic diversity is hard.
Inbreeding can happen
To prevent this, they keep a catalogue to maximise genetic diversity.
Why might animals kept in captivity not be able to live in the wild?
Diseases (they might not be resistant to the diseases)
Behaviour (looking for food)
Genetic races - the genetic makeup of the 2 can be so different that they can’t interbreed.
Habitat - the natural habitat must be large enough for 2 populations to live off of.
What are the main conservation agreements
International Union for Conservation of Nature
Convention on International Trade in Endangered Species
Rio Convection
Countryside Stewardship scheme
International Union for Conservation of Nature
Assist in securing agreements between nations. They make the red list of endangered species.
Rio convention
Convention on Biological Diversity
United nations Framework Convention on climate change
United nations convention to combat desertification.
Countryside stewardship scheme
Sustaining the beauty
Improving and extending the wildlife habitats
Restoring neglected land and conserving historic features.
Improving opportunities and countryside enjoyment.
What is Countryside stewardship scheme also called?
Environmental stewardship scheme
