4.2 Biodiversity Flashcards
What levels is biodiversity considered at?
Species, habitat, genetic
What is species biodiversity?
The number of different species found within a habitat. It includes species richness and evenness.
Define species richness
The number of different species
Define species evenness
Relative abundance of individuals of each species
Define habitat biodiversity
The range of distinct habitats in which different species live in an ecosystem (e.g. sand dunes, woodlands, meadows, streams)
What is genetic biodiversity?
Different breeds within a species measured via proportion of polymorphic gene loci
How can species richness and evenness be measured?
Richness: counting
Evenness: Simpsons index of diversity
What does a high Simpsons index indicate?
High biodiversity
High species richness and evenness
The ecosystem is stable and likely to withstand change
Not dominated by a particular species
How to produce a random sample to reduce bias.
- Take samples at regular distances
- Generate random numbers (coordinates)
- number of samples must be representative of area
- Take repeats and calculate mean
- Avoid recounting
- sample at different times
- identification key
Describe the sampling types
Stratified: different subgroups
Opportunistic: what turns up
Systematic: regular intervals
What does polymorphic and loci mean?
Polymorphic: more than 2 alleles
Loci: position of a gene on a chromosome
How can genetic diversity be assessed using calculations?
Proportion of polymorphic gene loci = number of polymorphic gene loci ÷ total number of loci
What factors affect biodiversity?
Human population growth, global warning due to climate change, agriculture
Problems with human population growth
Using resources such as land to our advantage
Loss of diversity
Extinction
Hunting
Killing for protection
Kill to prevent competition
Introduce new species
Contribute to climate change
How does climate change impact biodiversity?
Forest fires, drought, tropical storms, ice caps melt, coral bleaching
Organisms cannot tolerate change so don’t survive
Impact of agriculture on biodiversity
Monoculture (one crop species)
Removal of hedgerows
Deforestation
Soil depletion and erosion
Pesticides
Selective breeding
Economic reasons for maintaining biodiversity
Ecotourism, medicine source, scientific research, reduce soil depletion
Ecological reasons for maintaining biodiversity
Protect keystone species (interdependence/part of food chain), maintain habitats, maintain genetic resources
Aesthetic reasons for maintaining biodiversity
Enjoyed by future generations, protecting landscapes which are beautiful to look at
What is in situ conservation?
Protecting animals and plants in their natural habitat.
E.g. national parks, hunting bans, marine conservation zones, wildlife reserves
What is ex situ conservation?
Protecting animals and plants away from their natural habitat
E.g. zoos, botanical gardens, seed banks
Why is it better to store plants as seeds?
Produced in excess
Can be collected without damage to plant
Take up little space
Easier to store and transport
Less susceptible to disease
Genetic diversity
Viable for long periods of time
Advantage of in situ
More likely to survive in wild
Little human contact
Protect whole populations
Less disruption to animals
Disadvantages of in situ
Hard to enforce hunting bans
No protection from climate change
Cannot protect from extinction and intraspecific competition
Advantage of ex situ
Animals are well fed
Monitored and treated for disease
Reduced intraspecific competition
Protection from hunters
Reduce mortality of young
Young can be hand reared
Mating and artificial selection
Disadvantages of ex situ
Expensive, only care for small numbers, breeding less successful in captivity, less successful reintroduction, ethics
What is CITES?
- conservation of international trade in endangered species
Regulate and monitor trade in selected species, ensure trade in animals doesn’t threaten wild populations, less endangered animals can be traded, prohibit commercial trade of wild plants, allow artificially propagated plants to be sold
What is CBD?
Rio convention on biological diversity
Promote ex situ conservation, share scientific knowledge, share genetic resources, international cooperation, sustainable use of organisms/habitats/ ecosystems
What is CSS?
Countryside stewardship scheme
Sustainable beauty of the countryside
Maintain footpaths and remove litter
Improve habitats for animals
Preserve archaeological and historic sites
