4.2 biodiversity Flashcards
define biodiversity
variety of living organisms within a particular area
define species
a group of individuals that successfully interbred to produce fertile offspring
define habitat
where organisms/ species live
what are the levels of biodiversity
habitat biodiversity
species
genetic
define habitat biodiversity
number of different habitats within an area
benefits of high habitat biodiversity
more species are supported
what is species biodiversity made up of
made up of species richness and evenness
define species biodiversity
the number of different species present in an ecosystem and the relative abundance of each species
define species richness
the number of different species living in a habitat
define species evenness
how evenly represented species are/ comparison of number of individuals of each species
define genetic biodiversity
variety of genes that make up a species/ individuals belonging to same species
how do you measure species biodiversity
Simpson’s index of diversity
what does a greater genetic biodiversity mean
better adaption to a change in the environment/ individuals resistant to disease
what does simpsons index of diversity take into account
species richness and evenness
equation of simpsons index of diversity and what value does it give
D= 1-(sum of (n/N)*2)
between 0-1
what does a high Simpsons index of diversity mean
high value = more diverse habitat that are stable and can withstand change
what does a low SIOD mean
habitat is dominated by a few species
define allele/ gene variant
version of a gene
define locus
position of gene on a chromosome
define polymorphic gene locus
locus that has more then two alleles
how do you calculate genetic biodiversity
% of polymorphic gene loci in a population
polymorphic gene locus equation
no. of polymorphic gene loci/ total no. of loci
what is random sampling
sites are randomly selected using a random no. generator and grid
advantages and disadvantages of random sampling
+not bias
- may not cover all areas
- species missed
name the ways of non random sampling
opportunistic
stratified
systematic
what is opportunistic sampling
researcher chooses samples based on prior knowledge/ during the process of collecting data
chooses sample areas known to have species
advantages and disadvantages of opportunistic sampling
+easier and quicker
- biased and overestimate of area
what is stratified sampling
dividing habitat into areas which appear different
advantages and disadvantages of stratified sampling
+ species not underestimated
- over representation
what is systematic sampling
samples taken at fixed intervals using a transect
explain the two types of transects
line - samples taken directly on transect line
belt - quadrat placed on transect line
advantages and disadvantages of systematic sampling
+ useful when habitat shows clear gradient
- only species on transect line recorded
preparations for sampling
suitable clothing and footwear
apparatus
keys to identify plants
camera
when would random sampling not be used
if habitat is homogenous
methods for sampling plants
counting individually
quadrat
transect
methods for sampling animals
sweep netting
pooter
stout stick and white blanket
pitfall trap
tullgren tunnel
light trap
explain mark and recapture
capture animals in set time
count and mark them
release
recapture in same time
count and use equation
equation for mark and recounter
pop. size = no. 1st sample x no. 2nd sample / no. marked in 2nd sample
measurements of abundance
density
frequency
% cover
how to find density
no. selected species in quadrat counted
no. per square metre
how to find frequency
count no, of small squares species are present in
how to find % cover
estimate species in the quadrat
what do you consider when measuring biodiversity
species richness and evenness
What affects biodiversity
Human population growth
Agriculture
Climate change
explain how human population growth affects biodiversity
As population increases = demand for goods/ resources increases
Over exploitation
Urbanisation pollution
waste produced
Monoculture
Herbicides/ pesticides
Land use
What is over exploitation
Using resources faster than replacing due to growing demand
explain how agriculture affects biodiversity
Reduces hedgerows = loss of habitat, reduces genetic diversity
Monoculture = one strain of a species , drains minerals/ nutrients from the soil and turns to dust
explain how climate change affects biodiversity
Places getting warmer and colder
Species are unable to adapt to conditions
Migration of populations
Shift in biodiversity
State the reasons to maintain biodiversity
Ecological
Economic
Aesthetics
explain ecological reason to maintain biodiversity
Minimises disruption to food chain, pollinators, nutrient cycle
Protects keystone species
Genetic resource
Define keystone species
One that has a disproportionate effect upon its environment relative to its abundance
Give an example of a keystone species
Bees , wolfs
What is interdependence
Living organisms in a habitat depending on each other
Define niche
Match of a species to a specific environmental condition (habitat plus role)
Define endemic
Species is unique to a defined geographical location
Define conservation
Maintenance of ecosystems and biodiversity
explain economic reasons to maintain biodiversity
Natural ecosystems help
recycle nutrients
crop pollination
Regulate atmosphere/climate
Purification/retention of fresh water
Formation/fertilisation of soil
Detoxification/ recycling of waste
explain aesthetic reasons of maintaining biodiversity
Protects soil from erosion and the landscape
Tourism
Inspiration for writers/ painters
Define conservation in situ
Carrying out active management to maintain biodiversity in the natural environment
Name examples of in situ conservation
Wildlife reserves
Marine conservation zones
what is a wildlife reserves in conservation
Areas designated to conservation of species or habitats
How are wildlife reserves used for conservation
Controls grazing
Restricts human access
Controls poaching
Feeds animals
Removes invasive species
What is a marine conservation zone
Areas of the sea set aside to conserve the diversity of species and habitats
How do marine conservation zones conserve
Protects habitats
Creates areas of refuge so populations can grow eg. Coral and seaweed
What is a SSSI
Site of special scientific interest
Define conservation ex situ
Conservation outside the normal habitat of the species
Name methods of ex situ conservation
Botanic gardens
Seed banks
Captive breeding programme
Explain botanic gardens
Plant species are grown successfully with the right conditions and care (minerals, water, temp, C02)
Increases the number of plant species
Explain seed banks
Collection of seed samples that are stored at right conditions (dry, -20)
To stop plants germinating to keep them viable
Provides backup if species go extinct
Explain captive breeding programmes
Offspring produced in human controlled environment
Zoos/ aquatic centres
Provides animals with shelter , food , no predators, vets, breeding partners/ semen
name the international conservation agreements
CITES - convention of international trade in endangered species
CBD - convention of biological diversity
explain what CITES involves
international agreements between governments to ensure international trade in specimens of wildlife does not threaten their survival
explain what CBD involves
the sustainable development for use of biodiversity for peoples need for food, medicine, water, shelter, healthy environments etc.
name a local convention strategy
CSS - countryside stewardship schemes
explain CSS
providing financial incentives/ funding to farmers land owners to look after the local land
using buffer strips, hedgerow management, soil protection, low input grassland
