module 4 bio biodiversity

the number of different species and individuals within each species in a community

the variety of genes amongst all the individuals in a population species

the range of different habitats

the number of different species in a particular area at a particular time

its species diversity classified even further

mean you have lots of alleles for all the fdifferent genes therefore more likely for the whole population to adpat to its environment through natural selection

captive breeding

genetic bottleneck

founder effect

only a small number of individuals breeding togethr so limited gene pool and the same alleles keep being passed on

when only a small number of population hvae survived an event such as a disease

the gene pool is decreased and only the alleles in the remaining population can be passed on to future offspring

when from an original population a small number migrate to a isolated area

the small number of organisms that have migrated means that those individuals alleles are the only ones present

inbreeding is more likely as they are the only individuals there and so are going to pass on the same alleles

by examining polymorphic genes

a polymorphic gene is a gene that has more than one allele

most genes within the population only have one allele and are therefore monomorphic

to calculate genetic diversity you can measure the polymorphism using the formula

proportion of polymorphic gene loci = number of polymorphic gene loci/ total number of loci

the higher the proportion of polymorphic gene loci the larger the genetic diversity within the population

in terms of species diversity using index of diversity

the total number of organisms of all species

total number of organisms of a particular species

Simpson’s diversity index

it is the index of diversity

1

a larger value for D however its usually between 1-10

to measure the biodiversity of a habitat

use sampling becaus eit would take too long to count every individual in an area dn it is a way to get a representative of the population

take a large sample -can calculate means and statistical tests to see if any difference you see are significant

randomly sample - to avoid bias

lay out two tape measures at right angles to eachother to create a gridded area

use a random number generator to generate two numbers to serve as coordinates on the grid

place your quadrat on the coordinate and take your sample record the data

opportunistic, stratified and systematic

unlikely to result in a smaple that accurately represents the population

this megthod involves sampling organisms that are readily available therefore involves bias

some habitats or populations can be sorted into grouops to sample from or stratae.g. in a pond surface, shallow and deep water regions

you would then take random samples within each group

this method involves identifying dofferent areas within a habitat to sample it is used when there is a change in the distribution of species within a habitat and you want to investiagte the impact of the change on the biodiversity of the area

often involves a belt transect

this is when you would place a tape measure along the sample area and at a regular distance along the tape measure ypu would place your quadrat and record the data

used to sample plants and slow moving organisms

density - count the individuals present

frequency - quick method requires a gridded frame quadrat with 100 squares you would the count how many sqaures out of the 100 that yourt soecies is present in and calculate the %

Percentage cover - estimate the % of the entire quzdrsat covered with the species that is being investigted this method is quick but subjective therefore results in lower accuracy. can be inproved by standardising how the % is calculated eg using quadrat with 100 squares and counting 1% for every small square that is at least half covered w the plant

sweeping nets

pitfall traps

pooters

tullgren funnel

kick sampling

nets that can be used to capture insects in long grass

hole that can be dug in the ground and a pot is placed in it

small invertebrates may crawl into the trap and be unable to crawl out

a roof is placed over the trap to prevent it from filling with water and investigators will return daily to collect results and release the animals

used to extract small organisms from within soil samples

the soil sample is dried using a heat lamp and this causes teh animals to move in the opposite direction, downwards where a collecting dish is placed

used to sample organisms on riverbeds

one investigator will gentpy kick the river bed to disturb the earth and the organisms within is

a secon dinvestigator stands behind them with a net to capture any organisms that are released

the number of different species

sampling methods could be used to record that

for each species identified you woudl also have to recordthe number of individuals present

do you have a relativelyt equal amount of individuals of different species?

increase in human population increased need for space for food housing adn industry requiring deforestation

agriculture needed to feed the growing population clearing land for agriculture results in the destruction of habitats chemical pesticides or fertilisers may be added to the land and monocultures may be grown all of this reduces the number of habitast and range of food sources

climate change - increase in global temperatures melting polar ice caps caps therefore destroying habitatsalso resuting in sea levels rising which is reducing biodiversity due to flooding higher global temperatures amd lower rainfall means that certain plants and animals are unable to survive xerohpytes are becoming the dominant species in some areas with these plants outcompeting others as they can survive in harsher abiotic conditions

if an ecosystem experiences a loss in biodiversity this is a cause for concern as it indicates the change is causing a loss of habitats and therefore death and extinction of species often follows

reduction in biuodiversity is undesireable for economic, ecological and aesthetic reasons

agriculture reduces biodiversity as it removes natural habitats

all organisms are inetrdependent on each other and therfore the loss of one species imapcts all others

it is tehrefore imperative that we put in place conservation measures to protect these habitats but not to an extent that farming is no longer possible

deforestation can result in soil erosion adn monocultures can result in soil becoming deficient in particular minerals that crops absorb a lot of

both result in soil depletion and can negatively impact a countries ability to grow crops

tourism often relis on people visiting areas of natural beauty extinctions of animals plants and habitats could reduce tourism and therefore impact the economy

also many medicines have been based on chemicals naturally occuring in plants so plant species going extinct that could have potentially held the cure for disease in humans

being in nature and around plants and animals enriches people’s lives and this is why people may choose to visit different environments like the rainforest and beaches

nature is also a creative inspiration for art music and writers (think Romanticism)

being on nature has been shown to improve people’s mental health

in situ (within the natural habitat) and ex situ (not within the natural habitat)

happens within the natural habitat

getic diversity is maintained as individuals are not being bred captively

because species are interdependent putting measues in place in situ to prevent the extinction of one species will havre a positive impact on all other species dependent on it

eg marine conservation zones and wildlife reserves these areas are actively managed to conserve wildlife

involves removing organisms from their natural habitat to try and protect them usually used in addtion to in situ measures

eg. botanical gardens seed banks and captive breeding

seed banks are like a store of genetic materila they are kept in water and temoerature cpmtrolled envirnments to keep them viable for longer these are stored as a backup for potential plant soecies that may go extinct

captive breeding programmmes involve breeding aniomals in zoos and aquariums the aim is to increase the number of endangered species and these individuals can then be introduced into the wild