4.2.1 - biodiversity Flashcards
what is biodiversity
a measure of the variation found in the living world
what is a habitat
a place where species live
what is habitat diversity
habitats can range in size and structure and each habitat is occupied by a range of organisms
what is a species
a group of organisms similar in appearance and can breed to produce fertile offspring
what is species richness
a measure of how many different species are present
what is species evenness
a measure of how evenly represented a species are
what is genetic biodiversity
variation between individuals of the same species which can create breeds between species
how do you do random sampling
sample coordinates are selected using a random number generator and this is done before arriving on the site to reduce bias
positives of random sampling
data not biased
negatives of random sampling
may not cover all areas equally and species with lower presence may be missed
ways that you can trap invertebrates
sweep nets, pitfall trap, Tullgren funnel, pooter
how do you use a sweep net
walk through a habitat with a sweep net and sweep the net through vegetation in wide arcs
what is a pitfall trap
a trap set in the soil to catch animals
how does a pitfall trap work
- a small container is buried in the soil so the rim is just below the surface and any animals moving through will fall into the trap
- trap should contain some water or scrunched up paper so the animals don’t crawl out again
- in rainy weather, the trap should be sheltered from the rain so it doesn’t fill up
what is a Tullgren funnel
A device for collecting small animals from leaf litter
how does a Tullgren funnel work
- place the leaf litter in a funnel and the light above the litter drives the animals down as the litter dries out and warms up.
- they fall through the mesh screen and are collected in a jar under the funnel
How does a light trap work
- consists of a UV light attracting the insects.
- Under the light is a collecting vessel containing alcohol. Moths and other insects attracted to the light eventually fall into the alcohol
what is systematic sampling
transect is used when the environment changes from 1 place to another. Samples are taken at fixed intervals along a line laid out across a habitat
positives of systematic sampling
useful when habitat shows a clear gradient in environmental factors - ie grassland to woodland
negatives of systematic sampling
only species on the line/belt are measured leading to an underestimate
what is stratified sampling
divide habitat into areas which appear to be different and sample each section separately
positives of stratified sampling
ensures all areas of the habitat are samples and species are not under represented
negatives of stratified sampling
may lead to overrepresentation or there could be a disproportionate number of samples taken
what is opportunistic sampling
- researcher takes samples based on prior knowledge or during the process of collecting data
- they may sample an area they know contains a particular species
positives of opportunistic sampling
easier and faster than random sampling
negatives of opportunistic sampling
data may be biased or there may be an overestimation
how is species richness measured
taking random samples and counting the species present
A higher species richness indicates a greater diversity
how is species evenness measured
taking samples and counting individuals of each species
more evenness indicates diversity
what does simpsons index of diversity measure
the diversity of a habitat
what does n stand for in simspons index of diversity
total number of organisms in 1 species
what does N stand for in simpsons index of diversity
total number of all organisms
what does a higher value of simpsons index of diversity mean
- it is more diverse
- the habitat provides a place for many different species and organisms to live
- each species only represents a relatively small proportion of the habitat
- any change affecting 1 species tends to have a small effect on the whole habitat
- it is more likely to withstand change
what is polymorphsim
when a gene has more than 1 allele
example of a gene with polymorphism
hair/eye colour
what is monomorphism
when a gene only has 1 allele
what do monomorphic genes ensure
ensures that the basic structure of the species is similar
proportion of polymorphic gene loci
= number of polymorphic gene loci/total number of loci
why should biodiversity be maintained
- to maintain interdependence
- we can source medicine
- mangroves and coral reefs protect from extreme weather such as storm surges
- to maintain aesthetics
- economic reasons
- ecological reasons
human activities that reduce biodiversity
- cutting down trees
- pollution
- water pollution (affects species drinking from it/living in it)
- burning coal (releases greenhouse gases and causes global warming)
- hunting animals
- overfishing
ways we can maintain biodiversity
- afforestation (replanting trees)
- cutting carbon emissions
- use renewable energy
- consume less and responsibly
- eat meat and dairy responsibly
- reduce food waste
- educate people
- introducing laws and policies
ecological reasons for maintaining biodiversity
- protecting keystone species
- a species that has a disproportionate effect in its habitat
- ex - wolves in Yellowstone National Park
- a species that has a disproportionate effect in its habitat
- maintain interdependence of organisms
economic reasons to maintain biodiversity
- there are resources such as food
- nature does a lot of processes on its own such as pollination which would be expensive and time consuming for humans to do
- avoid monoculture - habitat with only one species
- if a new disease kills 1, all will be killed
- reduced biodiversity
aesthetic reasons to maintain biodiversity
ecotourism can be done
what are the main conservation agreements to protect species and habitats
- Convention on International trade in endangered species (CITIES)
- The Rio convention of biological diversity (CBD) 1992
- Countryside stewardship scheme (CSS) 1991 (CSS was replaces by the environmental stewardship scheme (2005))
what are the aims of the CITIES agreement
- regulate and monitor international trade in selected species of plants and animals
- ensure that international trade does not endanger the survival of populations in the wild
- ensure that trade in wild plants for commercial purposes is prohibited
- ensure that trade is artificially propagated plants is allowed, subject to permit
- ensure that some slightly less endangered wild species may be traded subject to permit, as agreed between the exporting and importing countries
what are the aims of the CBD agreement
- develop international strategies on the conservation of biodiversity
- using plant and animal products in a sustainable way
- appropriate shared access to genetic resources
- appropriate sharing and transfer of scientific knowledge and technologies
- fair and equitable sharing of the benefits arising out of the use of genetic resources
what are the aims of the CSS scheme
- improve the natural beauty and diversity of the countryside
- enhance, restore and re-create targeted landscapes, their wildlife habitats and historical features
- improve opportunities for public access
