4.2 biodiversity Flashcards
What is biodiversity?
a measure of the variation found in the living world
define habitat biodiversity
The range of habitats in which different species live
define species biodiversity
the range of organisms found in a habitat
define species
a group of organisms which can freely interbreed to produce fertile offspring
define genetic biodiversity
variation between individuals belonging to the same species, can create breeds
define sampling
selecting a small portion and studying that carefully
how is random sampling carried out
sample sites are randomly selected such as through random generation of coordinates
advantage of random sampling
ensures data isn’t biased through selective sampling
disadvantage of random sampling
may not cover all areas of habitat equally and can lead to underestimate of biodiversity
types of non-random sampling
Opportunistic, stratified, systematic.
how is opportunistic sampling carried out
researcher makes sampling decisions based on prior knowledge or during the process of collecting data
advantage of opportunistic sampling
Easier and quicker than random sampling
disadvantage of opportunistic sampling
data may be biased- can lead to overestimate of biodiversity
how is stratified sampling carried out
dividing a habitat into areas which appear different and sampling each area separately
advantage of stratified sampling
ensures all different areas of a habitat are sampled and species are not under represented
disadvantage of stratified sampling
may lead to overrepresentation of some areas
how is systematic sampling carried out
samples are taken at fixed intervals across the habitat
types of systematic sampling techniques
line transects and belt transects
advantage of systematic sampling
useful when a habitat shows a clear gradient in some environmental factor
disadvantages of systematic sampling
only species on the line or within the belt can be recorded, some may be missed and lead to underestimate of biodiversity
what preparation should be considered when sampling a habitat
suitable clothing and footwear
apparatus needed to carry out sampling
clipboard pen and paper to record observations
appropriate keys to identify plants
camera to record specimens and grid location
what is best to do when measuring biodiversity
use a range of sampling techniques- can be important if the habitat is not homogenous (even)
what is an important aspect to consider when sampling a habitat
the effect your presence will have on the habitat- sampling should cause as little disturbance as possible
what is the best way to count plants which are too small or there’s numerous
calculate a value of percentage ground cover occupied by each species
define quadrat
square frame used to define the size of a sample area
how may you use a quadrat with random sampling
generate random numbers then use them as coordinates to place the quadrats within the habitat
what can help with placing a quadrat accurately
a tape measure
what do you need to do inside the quadrat
identify the plants found and then calculate the percentage cover as a measure of their abundance
what do some quadrats have to make estimates more accurate
a grid of string that divides the quadrat into a number of smaller squares
what can you use to measure percentage cover
a point frame
what is a point frame and how do you use it
a frame holding a number of long needles
lower the frame into the quadrat and record any plants touching the needles
what should you not forget to record when using a quadrat and why
bare ground as its easy to bias your readings by using the point frame not randomly within the quadrat
what is the best way to use a point frame
at regular intervals across the quadrat
what is a transect and how do you use it
a line taken across the habitat
stretch a long string across the habitat and take samples along the line
what would you record with a line transect and where would you use it
the plants touching the line at set intervals along it
in a large habitat
define interrupted belt transect
Quadrat placed at regular intervals along the line
what does an interrupted belt transect provide
quantitive data at intervals across the habitat
define continuous belt transect
placing a quadrat beside the line and moving it along the line so you can study a band or belt in detail
identify the two types of transect
line transect and belt transect
how can you catch intevertebrates
- by sweep netting through a habitat with a stout net and emptying them on a white sheet to count
- placing a white sheet under a branch and knocking the branch with a stout stick so they drop and you can count them
what do you need to be carful with when catching invertebrates
you need to make sure to be quick as they may crawl or fly away
you can use a poster to collect animals before they fly away
what may you use a pitfall trap for and how does it work
to catch small animals
it is a small container in soil with a little water or scrunched paper so when animals fall in it they can’t crawl back out
when may you used a tullgren funnel and how does it work
to collect small animals from leaf litter
you place a leaf litter in a funnel and a light above the little drives the animals downwards so they fall and can be collected in a jar underneath the funnel
what can a light trap be used for and how does it work
to collect flying insects at night
has an ultraviolet light that attracts insects and they fall into a collecting vessel containing alcohol
what can you used a Longworth trap for and how does it work
for small animals without harming them
consists of near box which contains food in it then when animal enters it the door closes
what technique can you use to calculate population size
mark and recapture technique
how would you calculate total population with mark and recapture technique
capture sample of animals
mark each animal as C1
release the animals and leave traps for some time
animals captured mark as C2 and animals that where already marked are C3
multiply C1 by C2 then divide by C3
what problem is there with the mark and recapture technique
estimate calculated can be affected by animals that learn the trap is harmless or by animals that don’t like the experience so keep away from the trap after their first capture
what assumptions should you consider with the mark and recapture technique
- there is no migration
- no births or deaths
- all members of the population mix randomly
- the mark doesn’t harm the animal or affect the chances of recapture
define species richness
number of species found in a habitat
define species evenness
a measure of how every represented the species are
how would you use Simpsons index of diversity
E= sum of n= no of individuals of a particular species N= total number of all individuals of all species
how would you interpret data from using Simpsons index of diversity
the closer to 1 your answer is the more diverse the habitat is
the further from 1 your answer is the less diverse the habitat is
what can destroy a habitat
a small change to the environment such as a disease or predator
what populations have little genetic biodiversity
isolated populations such as captive animals in a zoo, rare breeds or pedigree animals
where is genetic diversity found
when there is more than one allele for a particular locus as it leads to variations that are more observable
how can you calculate genetic diversity
no. of individuals that have more than 1 allele/ total no. of loci X 100
what are polymorphic gene loci and how do you calculate it
loci with more than 2 alleles
no. of polymorphic gene loci/ total no. of loci
what factors affect biodiversity
human population growth
agriculture
climate change
how does human population growth affect biodiversity
- leanred to use environment to our advantage
- alter ecosystems to provide ourselves w/ food
- destroy and fragment habitats
- using more of earths resources
- pollute the atmosphere
how does agriculture affect biodiversity
- by clearing natural vegetation, reduces the size of habitats and population
- species gave less capacity to adopt to changing conditions
- modern agriculture relies on monoculture (1 type of crop) and selective breeding
- due to selective breeding other characteristics get ignored and die out
how does climate change affect biodiversity
- species are less able to adapt to changes in temp and rainfall-slow migration towards poles
- obstruction to migration include mountain ranges, large bodies of water, agricultural land
- selective bred plants cause little variation
- agricultural species unlikely to adapt and vulnerable to disease
- efficiency of agriculture will decline so crops grown in diff are and original areas will become desert
what is extinction
when last living member of a species dies and ceases to exist
why are domesticated species more at risk of extinction than wild populations
through selective breeding, you are getting rid of other alleles so if there were a disease, a species is less likely to survive
define keystone species
one that has a disproportionate effect upon its environment relative to its abundance
examples of keystone species
mountain lions- hunted to protect deer population
Beavers- build dams
Sugar maple- have roots which access water deep in soil and transfer it to make it accessible to there plants
bees- pollenate plants allowing them to reproduce
define soil depletion
loss of soil fertility caused by removal of minerals by continuous cropping
identify ecological interdependence of organisms reasons for maintaining biodiversity
if one species is affected by human activity and its numbers decline, it can affect other species
the decline of a keystone species can have catastrophic effect on environment
identify ecological genetic resource reasons for maintaining biodiversity
genetic diversity declining can destroy species as they won’t be able to fight off pests and disease
identify economic reasons for maintaining biodiversity
- growth of timber, food and fuel
- purification of fresh water
- formation and fertilisation of soil
- developing new medicines
- detoxification and recycling of wastes
identify aesthetic reasons for maintaining biodiversity
- experience feeling of wellbeing and patients recover quickly from stress and injury
- deforestation has been linked to severe flooding
- developing new medicines and vaccines
define conservation in situ
carrying out active management to maintain the biodiversity in a species natural environment
aim is to enable endangered species to survive and maintain biodiversity
how can legislation conserve species
pass laws to stop hunting, lagging and clearing land for development and agriculture
internationals laws can govern what people can import and export
what are the principles of choosing a wildlife reserve
- comprehensiveness: how many species in area
- Adequacy- is it large enough for survival
- Representativeness- is there full range of diversity
why have wildlife reserves led to conflict in the past
- protected animals escaped reserves and raided crops
- people continued to hurt protected animals for food
- illegal harvesting of timber or other plant products
- tourists fed protected animals or left litter
examples of wildlife reserves in the UK
- National parks
- National nature reserves
- sires of special scientific interest
- local nature reserves
- marine conservation zones
advantages of conservation in situ
- plants and animals conserved in natural environment
- protect biodiversity
- protect significant elements of natural and cultural heritage
- allow management of areas to ensure ecological integrity is maintained
- provide opportunities for ecologically sustainable land users
- facilitates scientific research
- possible to improve and restore ecological integrity of area
disadvantages of conservation in situ
- endangered habitats may be fragmented and not large enough for survival
- population may have already lost genetic diversity
- condition that caused habitat/species to be endangered may still be present
define conservation ex situ
conservation outside the normal habitat of the species
describe how zoos contributes to conservation ex situ
- concentrate of captive breeding- breed endangered species and conduct research to benefit them
- freezing eggs/sperm/embryos preserves large amounts of genetic material
- artifical insemination used on wild animals
- carry out research on common species similar to target special so endangered are spared from research but benefit long term from it
advantages of conservation ex situ
- organisms protected from predation and poaching
- health is monitored/ medical assistance if required
- populations can be divided/ if disaster strikes one, other is safe
- genetic diversity can be measured
- selective breeding to increase genetic diversity
- modern reproductive techniques increase chances of success
- breeding to increase no. of endangered species
- used for attraction to raise funds and for education
disadvantages of conservation ex situ
- captive population can mean limited genetic diversity
- animals exposed to range of diseases
- animals living outside natural habitat
- nutritional issues hard to manage
- animals might not behave normal
- correct environmental conditions hard to achieve and expensive
- when reintroduced to the wild, difficulties w/ acceptance by existing members of wild species
methods of conservation ex situ for plants
botanic gardens
seed banks
storage of seeds
why is conservation of plants easier than of animals
- plants have dormant stage (the seed)
- seeds are produced in large numbers
- seeds can be stored in protected surroundings and huge numbers
- captive bred individuals can be replanted in the wild
what are the problems with botanic gardens
- funding (ppl not as enthusiastic as w/ animals)
- collecting wild seeds causes disturbance
- collected samples may mot represent level of genetic diversity
- seeds from one area may be genetically different to those elsewhere
- seeds stored for long time may not be viable
- plants breed asexually (less genetic diversity)
- conclusions based from research on small sample not valid for whole species
how do seed banks contribute to conservation ex situ
- contain seeds that remain viable for decades
- seeds are stored and used to provide benefits for humanity
- store seeds for food crops, disease resistance crops for agriculture and repopulation of endangered species
how does storage of seeds contribute to conservation ex situ
- to pro-long viability they are stored in very dry freezing conditions
- 1% increase in moisture level, double life span
- 5*c reduction in temp, doubles life span
- seeds tested at regular intervals to check viability
identify the International agreements to protect species/habitats
CITES
Rio convention on biological diversity
Identify the aims of CITES
- ensure international trade of wildlife doesn’t threaten survival
- regulate + monitor international trade in selected species of plants + animals
- ensure trade in wild plants for commercial purposes is prohibited
- ensure trade in propagated plants is allowed
- ensure slightly less endangered species may be traded
why can the CITES policies be difficult to enforce
when there is demand for a product, there will be attempt to supply it (smuggling)
Identify the aims of the rio convention on biological diversity
- conservation of biological diversity
- sustainable use of its components
- appropriate shared access to genetic resources
- appropriate sharing and transfer of scientific knowledges and technologies
- fair sharing of benefits ringing out of use of genetic resources
how does the role of zoos, botanic gardens and seed banks play an international role
- ex situ conservation facilities in diff states provide support for eachother, share technologies and genetic materials
- sharing genetic material save time expense and distress to rare animals
- wild life reserves are essential for reintroduction to the wild
- plant breeding programmes can be enhanced by sharing stored specimens
identify local conservation schemes
the countryside stewardship scheme
identify the aims of the countryside stewardship scheme
- improve the natural beauty and diversity of the countryside
- enhance, restore and recreate targeted landscapes their wildlife, habitats and historical features
- improve opportunities for public access
what was the countryside stewardship scheme replaced by
environmental stewardship scheme
what are the aims of the environmental stewardship scheme
- look after wildlife, species and their habitats
- ensure land is well managed and retains its traditional character
- protect historic features and natural resources
- ensure traditional livestock and crops are conserved
- provide opportunities for people to visit and learn ab the countryside
