2. Biodiversity Flashcards
Biodiversity
measure of variation within the living world
3 types of. Biodiversity
Habitat, species, genetic
Habitat biodiversity
where an organism lives
Species biodiversity
Organisms that can interbreed to produce fertile offspring
Genetic biodiversity
Within the same species there’s variation of alleles
Random sampling
- number generator, coordinate generator
- Advantage = not biased
- Disadvantage = may not cover all areas of habitat equally
3 types of non random sampling
Opportunistic, stratified, systematic
Opportunistic
based on previous knowledge, know exactly where to sample. Adv = easier and quicker than random sampling. Dis = data is biased + can lead to overrepresentation something
Stratified
dividing habitat into segments of things that look different. Adv = allows you to sample everything that looks different = representative. Disadv = data is biased + can lead to overrepresentation
Systematic
when samples are taken at fixed intervals across habitat. Done w/ belt transect and line transect. Adv = clear gradient is visible. Disadv = data is biased + can lead to underestimation because only samples along the line will be measured
How to sample plants
To sample plants you use quadrats = everything that touches the grid you count. Point frame lowered after quadrat = same square and everything that touches the grid you count.
Quadrats can be places above transects as well
Observation to sample animals
if you can see them or droplets or footprints you can count them for larger animals
Pitfall trap
placed in ground with a little water to drown small invertebrates. May be more likely to come the second time of capture and release bc they know there’s food or may be less likely to come bc they known it’s a trap = influencing their behaviour.
Pooter
suck in small invertebrates to capture them
Using pitfall trap
- dig hole and place container in soil
- Make top of container level w soil level
- Cover to protect from rain
- Leave overnight
- Count invertebrates
Tullgren funnel
traps insects that are light sensitive = moves away from heat and goes into collecting pot. Ethanol in collecting pot underneath to kill the insects bc some may be predators some prey so if alive u won’t get an accurate representation.
Kick sampling
kicking the ground allowing the species to come out (small invertebrates in streams + rivers). Number of kicks + how vigorous kicks are. Disturbs organisms in the habitat
Sweepnet
catches invertebrates. standardised by controlling how many times you sweep and how high you sweep from the ground. Disturbs organisms in the habitat
What can be a limitation of a sampling technique
disturbing the organisms in the habitat
Capture and release formula
Everything you’ve captured you mark as c1. Let them go and put the trap there again and check who came back and which ones are unmarked. The ones that were already marked you mark as c3 and the ones that aren’t marked you mark as c2. Use equation (c1xc2)/c3 = total population.
Capture and release
The period between the first trap and the second trap should be quite short to stop animals from moving far away from the region. Animals may condition themselves to not come back because they think it’s a trap or they might think the trap isn’t harmless and will come back. Only people with a license can perform this experiment. You don’t want the marking to be toxic to the animal.
Species richness
a measure of how many different species there are
Species evenness
a measure of how many of each species there are
Species richness and evenness in a place w good biodiversity
High
Simpsons index
The value can be between 1 and 0 and the closer it is to one, the more diverse it is.
If a habitat has low biodiversity…
small change to the environment is likely to effect the whole habitat so the habitat is unstable and is unlikely to withstand change.
Locus
position of a gene on a chromosome.
How to assess genetic diversity
- The way we asses genetic diversity is by checking how many loci are polymorphic ( genes that have more than 2 alleles). For example hair colour is polymorphic but dimples aren’t.
- Proportion of polymorphic gene loci = number of polymorphic gene loci / total number of loci
Benefits of genetic biodiversity
allows for adaptation to changing environment, provides variation for natural selection, can offer camouflage from predators
What affects biodiversity
Human population growth, agriculture, climate change, extinction
Human population growth
need for more agricultural land, destroys habitats and more pollution produced
Agriculture
Monoculture and selective breeding to increase efficiency = reduces biodiversity selective breeding can lead to genetic erosion = overtime we’re losing some of our alleles. = reduced genetic diversity = inability to adapt to changing conditions
Monoculture
when there’s a field you grow the same crop again and again
Climate change
warmer climate, modern strains not adapted, migration may not be possible, more frequent flooding affects terrestrial ecosystems
Reasons to maintain biodiversity
Ecological, loss of genetic resources, economical, aesthetic
Ecological reasons
interdependence of organisms = organisms depend on eachother because they’re linked in a predator prey way. When one species is affected it can affect many other species.
Key stone species
have significant effect on ecosystem and many other species rely on their activity. If something effects the keystone species it will have a dramatic affect on the habitat
Loss of genetic resources
many drugs found in plants so maintaining biodiversity increase chance of finding new drugs and maintaining genetic resource for future
Economical reasons
purification of water, recycling of nutrients, crop pollination , growth of timber, food and fuel are done by organisms and if we reduce biodiversity and kill these organisms we won’t get these
What does monoculture lead to
soil depletion = soil is less fertile which means that eventually it can’t be used to grow crops.
Aesthetic reasons
greenery improves peoples physical and mental health
How does tourism increase biodiversity in an area
ecotourism = money from tourists used to support conservation
In situ conservation
when you want to conserve something in their natural environment, this can be done by creating local laws e.g. not being able to poach in a certain area, minimise tourism, you can create wildlife reserves. Whole aim is to prevent you from shaking the system and allowing some human activity to happen.
Examples of in situ conservation
national parks, marine conservation zone
In situ advantages
plants and animals are conserved in their natural environment, permanent method to protect biodiversity, allows managements of this area, facilitates research, if biodiversity was declining in this area in situ conservation gives you the possibility to restore it
In situ disadvantages
population may have already lost too much of its genetic diversity, condition that caused the initial threat may still be present, area can be targeted by poachers and eco tourists
Ex situ
conserving the habitat outside of the normal habitat,
Ex situ examples
g. zoos, sperm banks, seed banks, botanic gardens
Ex situ advantages
animals are protected from poaching and predators, health of the animals can be monitored and medical help can be given, genetic diversity can be restored, reproductive technology can be used to increase species number, good place for education
Ex situ disadvantages
because it is a captive population there will be low genetic diversity, organisms are living outside of their natural habitat = may not behave as normal and reproduction may be difficult, the ideal environment conditions would be hard to maintain, animals may not be able to be reintroduced to the wild
Benefit of reintroduction of species
Ecotourism, education
Seed banks
we can store seeds for a long period of time without taking up a lot of space.
Disadvantage of seed banks
funding, collecting samples would give you low genetic diversity, some seeds may not be viable,
to store a seed (to make it viable) it has to be in a very dry or freezing condition
CITES
convention of international trade in endangered species)
- Aim is prevent trade in endangered species and restrict international wild life trade
Rio convention
- aims to conserve biological diversity while maintaining the need of people
- sustainable use of biological resources
The country stewardship scheme
- Local uk scheme
- Landowners were paid to maintain the land = to conserve English landscape
- In 2005 the scheme changed to environmental stewardship scheme which is when grants were given to farmers and land managers to conserve and protect the landscape including animals + habitats + historical features
Preservation
keep something the exact same as it is = let natural stuff occur DONT let human activity disturb it
Conservation
actively doing something to protect the species
Why may a species be endangered in the wild
loss of habitat or hunting
Increasing habitat diversity affect on species diversity and genetic diversity
species diversity = more species live in new habitats and increases
genetic diversity = species have wider range of conditions to live in
Why is extinction sped up if populations are small and scattered in isolated areas
hard to find a mate and low genetic diversity due to inbreeding = can’t cope w environmental disease + all wiped out by same disease
Genetic biodiversity affect on small population
- genetic diversity low
- Small gene pool
- Inbreeding = genetic erosion = low potential for adaption to future change + can’t cope w environmental distress + all wiped out by same disease
Decrease in Species biodiversity affect on small population
- may go extinct = one less species
- Former prey species may increase
- Affect food chain
