M4 C11:biodiversity Flashcards
what is biodiversity?
the number of different ecosystems and habitats in an area, the number of species within the ecosystems and the genetic variation
what is a habitat?
where an organism lives
what is a species?
a group of organisms of common ancestry that interbreed to give rise to fertile offspring
what are the 3 levels of biodiversity?
habitat
species
genetic
what is habitat biodiversity?
where species inhabit included both abiotic and biotic factors. number of different habitats in area
examples of abiotic factors?
air, soil, temperature, light, water
examples of biotic factors?
food webs, competition, predators,
what is species biodiversity?
species richness- no of dif species
species evenness- no of each species
for example there may be a high species richness but a low species evenness if the area is dominated by 1 species more than the rest
what is genetic biodiversity?
genetic diversity- variation of alleles within species.
this allows better adaptation if species to a changing environment. this is often limited in smaller populations due to inbreeding
what is sampling?
taking measurements of a limited no of organisms present in a specific area
what must sampling be representative of?
size or area of transect
repeat measurements
accounting for different times of the year
what 3 things do quadrats measure?
species frequency- % of quadrats with the species
species density/ richness- no of individual organism in quadrat
percentage cover- % of area of quadrat with the organism
what is random sampling?
taken to avoid any bias, random generators are used to determine coordinates for sampling, each site has an equal chance of being chosen
what is opportunistic sampling?
most biased, researcher makes sampling decisions based on prior knowledge or during process. may use favoruable areas
what is stratified sampling?
habitat divided into areas which appear different and each area sampled differently to include all different areas
what is systematic sampling?
taken at fixed intervals across the habitat
either using a;
belt transect-provides info on quadrats along transect line
interrupted belt transect- records at set intervals along transect line
line transect- records species touching transect line
evaluate random sampling?
least bias as every site has an equal chance of being used
time consuming and may only cover 1 area
evaluate opportunistic sampling?
more chances of species being present and is easier and quicker
most bias- observer bias
evaluate stratified sampling?
takes all areas into account
may be over representative and biased as lots of area is covered
evaluate systematic sampling?
more representative
some species may be missed if not close to transect line
how else can we sample animals?
beating tray
pooter- suck animals into a glass
sweep net
pond net
pitfall trap- trap covered with lid to keep out rain
what is the capture- mark- release- recapture method to sample animals?
catch fist sample and mark them
release them back into environment
after a certain time catch another sample, some in this may be marked from the first sample
smaller no of marked individuals= larger population
how do we estimate population by the Lincoln index?
population size= sample 1 x sample 2 divided by no of marked in sample 2
what formula dop ypu use to calculate biodiveristy?
simpsons index
what are some features of a low biodiversity habitat
-few successful species
-extreme environment
-few species live, these have specific adaptations
-simple food webs
-major effecdts on ecosystem due to change om the enmvionemnt
what are some features of a high biodiversity habitat?
large number of species
more ecological niches
many species with less specific adaptations
complex food webs
changes to environment havea small effect on the ecosystem
how is genetic biodiversity increased?
mutations arise that causes difference in alleles
why is genetic biodiversity important?
allows species to adapt to future environmental changes and avoid inbreeding. Inbreeding, which happens when there are small, isolated populations, can reduce a species’ ability to survive and reproduce.
what decreases genetic diversity?
selective breeding
captive breeding
rare breeds
artificial cloning
natural selection
genetic botlenecks
founder effect
genetic drift
what are genetic bottlenecks?
when few individuals in a population survive an event/change reducing the gene pool
what is the founder effect?
where a small number of individuals create a new colony isolated from the individual
what does genetic drift mean?
due to random nature of alleles being passed on, the frequency of occurrence of alleles will vary
what is polymorphism?
occurs when there are two or more alleles present at a single loc
what is the main cause for loss of biodiveristy?
humans as we use many resources from the Earth such as land.As the human population increases and countries become more developed, our requirement for these resources also increases
having a harmful effect on the environment, including aquatic and terrestrial ecosystems and climate
The damage to these ecosystems is negatively impacting the species and habitats contained within them
why is agriculture decreasing biodiversity?
increase in land farmed to accommodate the population so deforestation takes place killing habitats
monoculture where farmers grow 1 plant reduces habitats and selectively breeding decreases genetic biodiversity
why is climate change decreasing biodiveristy?
-release of pollutants from burning fossil fuels increases global temperatures
-melting ice caps leads to extinction of species living there,
-rising sea levels which could cause flooding decreasing land habitats.
-Hot temperatures means some species will die and xerophytic species become dominant
what effect do keystone species have on biodiversity
they help maintain structure and have large effect on environment disproportionate to their abundance
if they leave other species may disappear or be affected
what are aesthetic reasons for maintaining biodiversity?
brings people joy and ecotourism
what are ecological reasons for maintaining biodiversity?
protecting species especially keystone species as if one species disappears others might to
maintaining genetic resources which can adapt to change
what are some examples of keystone species?
wolf- prey is elk they increase and overgrazed which causes other species to die
what are the economic reasons for maintaining biodiverdity?
-soil depletion by monoculture means increased spending on fertilizers
-ecosystem services- water from transpiration of plants adda to our water
-water filters throguh rocks
-pollinators ensure crops are fertilised to provide food
-discovery of medicine
-ecotourism, areas appreciated by many
how is biodiversity maintained?
conservation
what are the 2 types of conservation?
in situ
ex situ
what is in situ conservation?
protection of area so species can continue to live in their original habitat
what is involved in in situ conservation?
legislation
wildlife reserves
repopulation
how can legislation conserve biodiversity?
laws can include prohibiting hunting or restricting logging and clearing of land. international laws cover what countries can import and export. these can be hard to enforce though
what are wildlife reserves?
areas set aside for conservation of species or habitats
key features of wildlife reserve sites?
has a range of diversity within it and is large enough for long term
Humans access is strictly controlled
Industrial activities such as agriculture and building are tightly regulated
Hunting is limited or completely prohibited
what are some examples of wildlife reserves?
national parks
national nature reserve
marine conservation zones
what are the advantages and disadvantages of wildlife reserves?
+species in natural environment
+facilitates scientific research
-area may become popular to ecotourists causing disturbance
-conditions causing species to be endangered may still exist in natural environment
what is repopulation?
process of restoring or increasing the size and abundance of a population of a particular species that has declined due to various factors
what is ex situ conservation?
removal of species to a protected place that is not its normal habitat
what are some types of ex situ conservation?
zoos
botanic gardens
seed banks
international conservation
how do zoos conserve biodiversity?
-run captive breeding of endangered species so they can get a stable population of the species, then reintroduce them to their habitat
-they ensure inbreeding doesn’t occur by looking at genealogical data and use techniques such as IVF.
-also can be used to educate people about endangered species
what are the pros and cons of zoos?
+protection from predators
+selective breeding can increase biodiversity
-animals may not be accepted back into the community when back in normal habitat
-expensive to maintain
how to botanic gardens conserve biodiversity?
conserve endangered plants, easier to do so than animals. involves controlled environments to grow rare plants for research and display + conservation
what are seed banks?
collection of seed samples from every species of plants, can be viable for years and are stored in very dry or freezing conditions, can be used for repopulation.
pros and cons of seed banks and botanic gardens?
+ plants can reproduce asexually
+seeds can be stored without taking up too much space
-difficulty funding compared to animals
-no genetic diversity
what are some examples of international cooperation?
Rio convention- aims to develop international strategies on conservation
cites agreement- regulates trade if wild animals and plants, and makes it illegal to kill endangered species
countryside stewardship scheme- encourages hedgerows via financial incentives
