4.2.1 Biodiversity Flashcards
What are the different levels of biodiversity?
Habitat/ecological- all the different habitats/ ecosystems present in an area
Species- species richness is total number of different species in an area and species even evenness is the distribution of numbers of individuals of each species in an area
Genetic- the variety of alleles present in each species populations of an area
How can we sample animals?
Pooter- sucking air containing insects into a plastic container via a tube
Sweep net- net swept in figure of 8 motion in grass or air
Pitfall trap- catches invertebrates in a hidden trap
Tree beating- shaking or beating trees to dislodge insects onto white sheet below
Kick sampling- kicking river bank and catching organisms downstream
How can we sample plants?
Frame quadrat
Point quadrat
Can use density, frequency or percentage cover to estimate populations
How can we eliminate sampling bias?
Limit human involvement by random sampling
Take measurements from randomly selected individuals of organisms being investigated
Use large sample size (minimises results from chance)
What is stratified sampling?
Divides population into strata
Random samples taken from each stratum which are proportional to the strata size
What is systematic sampling?
Non random sampling with readings taken at regular intervals (transects)
What are abiotic factors which can effect species distribution
Light
Humidity
Temperature
pH
Wind speed
Measuring these allows to detect rapid changes in conditions.
How can we calculate genetic diversity within a population?
Proportion of polymorphic gene flow= number of polymorphic gene loci÷ total number of loci
What is the importance of high genetic diversity?
Large variety of alleles in a populations gene pool allowing the ability for the populations to adapt to changing environment, helps avoid extinction.
Increases with random mutations and gene flow
What decreases biodiveristy?
Deforestation- destroys habitats, exploits resources which can cause a decline or extinction of some species
Urban sprawl- isolates wildlife populations which limits gene flow
Pollution- directly kills species and harms habitats long term
Agriculture- maximising crop yield means monocultures, depletes soil minerals and less animals able to survive. Herbicides and pesticides kill some species and effect organisms higher up in food chain.
Climate change- alters regional climates causing shifts in biodiversity, makes areas less inhabitable. Can influence migration patterns
What are reasons for conserving biodiversity?
Ecological- food webs rely on multiple species, removing one can destabilise. Important for nutrient cycles.
Economic- support industries, medicinal compounds can be discovered from wild species, and ecotourism.
Aesthetics- inspiration for many artists and can help management of stress
What are some global schemes to increase biodiversity?
Rio convention- sustainable use of resources, legal responsibility to protect, stabilise greenhouse gas emissions and provides guidance for governments
CITES- makes trade of endangered species illegal, regulates trade by having license requirements and educates to raise awareness.
IUCN- secures international agreements and publishes a red list of threatened species with detailed conservation status.
What is in situ conservation?
Protects species within their natural habitat. Allows larger populations to be protected with a greater chance for recovery.
National Parks
Wildlife reserves
Marine zones
What is ex situ conservation?
Relocates species to safer regions and reintroduces back to original habitat once population and conditions are stable
Zoos
Botanical garden
Seed banks
