4.2 Biodiversity Flashcards
Biodiversity meaning:
Variety of living organisms in an area
Species meaning:
Group of similar organisms which can reproduce and make fertile offspring
Habitat meaning:
Area inhabited by a species, including physical factors (biotic and abiotic)
High biodiversity meaning:
Lots of different species
Habitat diversity meaning:
No. of different habitats in an area. Eg. sand dunes, woodland, meadow
Species diversity meaning:
No. of different species and abundance of each species in an area
Species richness meaning:
No. of different species in an area
Species evenness meaning:
Abundance of each species in an area
Genetic diversity meaning:
Variation of alleles within a species (eg. dog breeds)
Method to sample plants:
Quadrat
Method to sample flying insects:
Sweep net (net on pole)
Method to sample ground insects:
Pitfall trap
Method to sample aquatic animals:
Net
How to sample (steps):
- Choose area.
- Count individuals (w/ quadrat, net, etc).
- Repeat.
- Use results to estimate total.
Comparing different habitats samples:
Use the same sampling technique
How do you get a random sample?
Split field into a grid, use measuring tape and a random number generator to select coordinates.
When would you take a non-random sample?
When there’s a lot of variety in distribution of species in the habitat, want to make sure all areas are sampled.
Systematic sampling description:
Samples taken at fixed intervals, often along line.
Opportunistic sampling description:
Samples chosen by investigator. Simple but biased.
Stratified sampling description:
Different areas identified + sampled separately in proportion to habitat as a whole.
Non-random sampling techniques:
Systematic, opportunistic, stratified
Greater species richness meaning:
Higher number of species
Greater species evenness meaning:
Population sizes of each species are similar
Simpsons index of diversity equation:
D = 1 - (sum(n/N)^2)
n = total number of individuals in one species
N = total number of organisms in all species
Simpsons index of diversity meaning:
Closer to 1 = more diverse habitat, higher species richness and evenness
Simpsons index of diversity range:
0
Low genetic diversity problems:
Can’t adapt to change in environment, whole population can die from a single disease
Which population types may have low genetic diversity?
Isolated populations, bred in captivity, zoo animals, pedigree
Why is monitoring genetic diversity important?
To increase if necessary. Breeding programmes in zoos need max genetic diversity
Polymorphism meaning:
Locus with 2 or more alleles
Where are alleles of the same gene found?
Same point (locus) on chromosome
How to measure genetic diversity?
Find proportion of polymorphic gene loci in an organism
Measure of genetic diversity equation:
Proportion of polymorphic gene loci =
Number of polymorphic gene loci)/(total number of loci
Factors affecting global biodiversity:
- Human population growth.
- Increased use of monoculture in agriculture.
- Climate change.
How does human population growth decrease global biodiversity?
- Habitat loss.
- Over-exploitation.
- Urbanisation.
- Pollution.
How does habitat loss decrease global biodiversity?
Human development destroying habitats, animals can’t live there, lower habitat diversity.
How does over-exploitation decrease global biodiversity?
Greater demand for resources from growing human population. Used up faster than produced. Can cause extinction. Decreases genetic and species diversity
How does urbanisation decrease global diversity?
Cities and roads isolate species, populations can’t interbreed, genetic diversity decreased
How does pollution decrease global diversity?
Pollutants kill some species and habitats. Decreased biodiversity.
How does increased use of monoculture in agriculture decrease global diversity?
Habitats lost for large fields, low habitat diversity.
Local/naturally occurring plants seen as weeds and killed, lower species diversity.
Heritage varieties don’t make money, aren’t planted, lower species diversity.
Climate change description:
Variation in earths climate. Changes in temp and rainfall pattern.
Human influence on climate change:
Humans increasing emissions of greenhouse gases (eg. CO2). Causes global warming, which causes other climate changes.
How does climate change affect areas of the world?
Very differently.
Some warmer, some colder, some wetter, some drier.
Why does climate change affect global biodiversity?
Inhabitable place becomes uninhabitable.
Species range may in/decrease.
Species migrate.
Species can go extinct if they can’t migrate and change is too fast.
Species range meaning:
The area in which they live
Ecological reasons to maintain biodiversity:
- To protect species, including keystone species.
2. To maintain genetic resources.
Keystone species meaning:
Other species in the ecosystem depend upon them. Without them ecosystem changes dramatically. Often predators (keep population in check), sometimes modifiers (maintain environment)
Effects of disruption to food chains:
Affects both prey and predator
Effects of disruption to nutrient cycle:
Eg. worms increase quality of soil. Less worms = lower soil quality = bad growth of plants = less food for animals.
Affects growth of plants and amount of food for animals
Genetic resources meaning:
Any material from plants, animals, microorganisms. Ones that contain genes we find valuable, eg. crops, medicine, industrial processes
Why maintain genetic resources?
- Provide variety of everyday products.
2. Allow us to adapt to environmental changes, eg. drought resistant genes.
Examples of genetic resources:
Food and drink. Clothes (cotton and leather). Drugs. Fuels (renewable). Industrial materials (wood, paper, oil, pesticides, dyes, adhesives, rubber).
Economic reason to maintain biodiversity:
Reduce soil depletion
Monoculture meaning:
Growing single variety of single crop
Continuous monoculture meaning:
Plant same crop in same field without interruption over time
Continuous monoculture problems:
Soil depletion from using up nutrients required by that crop
Economic cost of soil depletion:
Increased spending on fertilisers, decreased yield in long run.
Aesthetic reason to maintain biodiversity:
Biodiversity brings joy to millions of people. Areas rich in biodiversity are pleasant and attractive landscapes. More biodiversity = more visitors = more money
In situ conservation meaning:
On site conservation. Protecting species in natural habitat.
In situ methods of conservation:
Making protected areas.
Restricting urban/industrial development there.
Control introduction of new species.
Protect habitats.
Promoting particular species (protecting food source or nest).
Legal protection to endangered species.
Advantages of in situ conservation:
Both species and habitat conserved. Large populations protected, less disruptive than ex situ. Higher recovery chance.
Disadvantage of in situ conservation:
Difficult to control factors threatening species (poaching, predation, disease, climate change)
Ex situ conservation meaning:
Off site conservation, removing part of a species from threatened habitat, place in new location. Last resort.
Ex situ methods of conservation:
Relocation to safer area.
Breeding in captivity, reintroduction when older.
Botanic gardens are controlled environments.
Seed banks to freeze and store seeds in case of natural disaster.
Advantages of ex situ conservation:
Protect individual animals in controlled environment.
Reintroduce species that left the area.
Disadvantages of ex situ conservation:
Only small number of individuals can be cared for. Difficult and expensive to sustain environment. Animals more likely to catch disease from humans and not display natural behaviour.
Breeding less successful.
Rio convention on biological diversity (CBD):
- Aims to develop international strategies for sustainable use of resources and conservation of biodiversity.
- Made conserving biodiversity everyone’s responsibility by law.
- Provides guidance to governments.
CITES (Convention on international trade in endangered species) agreement:
- Aims to increase international cooperation in regulating trade.
- Illegal to kill endangered species.
- Conserve species, limits trade through licensing, illegal to trade in products from endangered animals.
- Raise awareness of threats to biodiversity through education.
Countryside stewardship scheme (CSS):
Introduced 1991. Aimed to conserve biodiversity and promote specific land management techniques to improve and extend wildlife habitats.
10-year agreement from government, pay landowners who followed suggested techniques. 10,000 agreements in uk in 2000.
