biodiversity Flashcards
biodiversity definition
the variation that exists within and between all forms of life
why is biodiversity important
it helps the resilience of ecosystems as it allows organisms to resist + cope with changes in their environment
3 main types of biodiversity
habitat diversity
species diversity
genetic diversity
habitat diversity definition
the number and range of different ecosystems and habitats
how dies habitat diversity contribute to biodiversity
if there is a large range of different habitats within an area, that area is more likely to have a high biodiversity
e.g. a coral reef = very complex with many microhabitats
vs the desert = similar conditions throughout area
species diversity definition
the number of species in an area and their relative abundance
what 2 factors make up species diversity
species richness and species evenness
species richness definition
the total number of species in 1 ecosystem
species evenness definition
the evenness of abundance of each species in an ecosystem
how does species diversity contribute to biodiversity
high species richness + high species evenness = high species diversity = higher biodiversity
how does species diversity relate to the stability of an ecosystem
ecosystems with high species diversity tend to be more stable as they are more resilient to changes in their environment
genetic diversity definition
the genetic variation within a species
gene pool definition
all the alleles for all genes in a species
how does genetic diversity relate to the stability of an ecosystem
- some genes within a species have different alleles
- this leads to genetic diversity within a species
- this allows for better adaptation to environmental changes + selection pressures
give 2 biotic selection pressures
- new predators
- pathogens / disease
give 3 abiotic selecton pressures
- changing temperatures
- changing rainfall
- changing humidity
loci definition
the specific position of a particular gene on a certain chromosome
what are the some causes + consequences of low genetic diversity
low genetic diversity may occur in small isolated populations or as a result of inbreeding
it can cause a high proportion of homozygous individuals which reduces genetic diversity
it also means genetic diseases caused by recessive alleles become more common
give 3 ways to measure genetic diversity
- measuring the proportion of polymorphic gene loci
- measuring the proportion of the population that is heterozygous for any specific gene locus
- measuring allele richness
polymorphic loci definition
a loci/genes with 2 or more alleles
how can genetic diversity be assessed
through examining phenotypes - for some genes, the expression of different alleles produces observable differences
or through examining DNA sequences / proteins of alleles
give the formula for calculating the proportion of polymorphic gene loci
P = proportion of polymorphic gene loci =
(no. polymorphic gene loci) / (total no. gene loci examined)
give 1 limitation of using the formula for calculating the proportion of polymorphic gene loci to calculate genetic diversity
- it doesn’t illustrate the alle richness of a species as the no. of alleles for each gene locus are not the same
outline the 2 other ways genetic diversity could be assessed
- comparing the amino acid sequences of proteins / alloenzymes, and how they may function differently
- comparing DNA sequences, as genetic code is degenerate, this is more effective than comparing amino acid sequences, as the sequence could be the same but the base sequence could be different
alloenzyme definition
slightly different forms of the same protein, coded for by different alleles
give 1 method of measuring levels of biodiversity + a limitation of this method
identifying + cataloguing all organisms in an ecosystem, this allows a species list to be built, showing the species living in an ecosystem and their population sizes
- this may only be possible where species are very large or where the area is very small, in large complex ecosystems e.g. rainforest this isn’t feasible
give 1 method of measuring biodiversity that is more applicable to larger or more complex ecosystsems
sampling - taking different samples of the area + using them to estimate the total number of species
what is the simpsons index + the formula
a formula used for measuring species diversity as it takes into account both species evenness and species richness
D = 1 - (Σ(n/N)^2)
D = simpsons index
n = total number individuals for 1 species
N = total number individuals for all species
what does the D (simpsons index) value tell you
D can fall between 1 and 0
near 0 = low biodiversity
near 1 = high biodiversity
sampling definition
a method of investigating abundance + distribution of species populations
what are the 2 types of sampling
random
non random
what is random sampling
this is when the positions of sampling points are random, there is no bias by the sampler that could affect results - this is more representative of the whole area
what is non random sampling
this is when the positions of sampling points are chosen by the sampler, meaning there could be bias towards a certain area e.g. places with lower species diversity as it’s faster to count - this could be unrepresentative of a whole area
what is non random sampling
thi
give 6 methods used in random sampling + what they measure
- quadrants placed randomly - distribution of plants + slow moving animals
- sweeping nets - flying insects or those living in long grass
- pitfall traps - ground dwelling insects
- pooters + suction e.g. from a mouth- small insects
- tullgren funnels with light bulbs above - invertebrates living in soil, light + heat forces them down until they drop into container
- kick sampling + net - freshwater invertebrates
when is non random sampling appropriate
when random sample isn’t possible or will take too long
what are the 3 types of non random sampling
opportunistic
stratified
systematic
opportunistic sampling definition
when sample locations are chosen based on other non random factors, e.g. areas that are nearby, safe to reach
stratified sampling definition
involves matching number of sampling locations with relative proportion of the area that a specific habitat covers - used when a single area contains many habitats e.g. woodland, fields, bare soil, etc
systematic sampling definition
sampling with transects at regular intervals to show how species distribution changes across an area, used when there is a clear change in physical conditions occurring across an area, e.g. altitude, light intensity, salinity
why has human population increased exponentially for the last few hundred years
improvements in technology which increases food supply, as well as medicine, hygiene and healthcare - this has increased birth rates and decreased death rates
why does the growth of the human face threaten biodiversity
humans use lots of resources from the earth, e.g. land, water, fuel
as population and economic development increases, demand for these resources also increases
this has harmful effects on many ecosystems and organisms living within them, as well as the climate
give 5 main factors affecting biodiversity
- habitat destruction
- over exploitation
- hunting
- agriculture
- climate change
how is habitat destruction affecting biodiversity + 2 examples of specific habitats
- land is cleared for agriculture, industry, housing, water storage, etc
- this can result in habitat loss or fragmentation, which threatens the organisms living in them
EXAMPLES
forests - deforestation is very damaging as forests often have very high levels of biodiversity
the ocean - marine habitats like coral reefs are destroyed due to extreme fishing methods, like dynamite
what is the difference between habitat loss and fragmentation + a consequence of each
habitat loss - when habitats are completely destroyed, this threatens the survival of the organisms living in them
habitat fragmentation - when habitats are divided into small areas, populations may suffer from local extinction or inbreeding
how is over exploitation affecting biodiversity
many natural resources are being used faster than they can be replaced
e.g. deforestation is not sustainable as trees are being cut faster then they are being replanted
how is hunting affecting biodiversity
many wild, non farmed species of animal are being hunted and removed more quickly then populations can be replenished e.g. rhinos
how is agriculture affecting biodiversity - 7 damaging practices
there is now a need to produce food at a faster rate, farms have become more specialised + modern through:
- monoculture - lower biodiversity compared to natural habitats
- growing cereal crops rather than vegetables
- making fields larger so they accommodate machinery
- removing hedgerows - an important habitat, supported wildlife is now gone
- draining wetland or filling in ponds to make more agricultural land
- fertilisers - can leach into water and kill aquatic organisms
- pesticides - can also kill many non target species e.g. bees, which are essential pollinators
why is it difficult to implement ecologically friendly practises in farming
high yields and profits make farming economically viable
however farming practises that maintain + increase biodiversity are much more expensive and labour intensive, and can sometimes reduce livestock or crop yields
e.g, not using pesticides means less organisms are harmed but plants are destroyed by actual pests, decreasing yield of high quality crop
how is climate change affecting biodiversity - 3 negative consequences
climate change affects weather patterns and the frequency of extreme weather events e.g. floods, hurricanes
- it may be occurring too fast for organisms to be able to adapt, potentially resulting in extinction, decreasing biodiversity
- global warming causes many species to move towards poles, increases competition in these areas, decreasing biodiversity
- marine life is threatened by global warming which increases ocean temperatures, leading to coral bleaching, as well as increasing CO2 emissions which dissolves in seawater making it more acidic - both of these cause habitat destruction, leading to major biodiversity loss
outline ecological reasons for maintains biodiversity
high biodiversity means more stable ecosystems which are more able to adapt to changes, and ensures the survival of keystone species
keystone species definition
a species which is essential for maintains biodiversity, they have a disproportionately large effect on their environment relative to their abundance
outline economic reasons for maintaining biodiversity
ecosystems can have a lot of economic value such as through
- medicines that are derived from plants + fungi + bacteria
- ecotourism
- many scientific + technological contributions have come from nature in specific ecosystems, reasonable to assume there are many things in nature that could benefit humans
outline aesthetic reasons for maintaining biodiversity
humans find pleasure + joy + peace in the beauty of nature
helps ecotourism
outline social reasons for maintaining biodiversity
many people enjoy spending time in nature e.g. hiking, climbing - these activities could be lost if environments aren’t conserved
outline moral reasons for maintaining biodiversity
humans have a moral obligation as the most intelligent species to protect against the loss of biodiversity resulting from human activity - we share the planet with other organisms, we shouldn’t be causing their extinction
outline environmental reasons for maintaining biodiversity + 5 examples
humans need diverse ecosystems because of the essential environmental services they provide:
- plants absorb CO2 from atmosphere, reducing greenhouse effect
- microorganisms can digest masses of organic waste
- plant transpiration allows us to have irrigation and drinking water
- fungi and bacteria are essential to nutrients cycle and maintaining soil nutrition
- plants are producers, indirect + direct energy source for humans
outline agricultural reasons for maintaining biodiversity
most crops are uniform, low genetic diversity, and wild variants that can provide new alleles are under threat due to climate change + habitat destruction
also low diversity among plants increases susceptibility to disease, wild variants could be bred with farm crops to introduce variation
what are the 2 main types of conservation of endangered species
in situ and ex situ
what is in situ conservation + example
a method of conservation where organisms are kept in their natural habitat as all support systems needed for their survival already exist e.g. national/marine parks
what is ex situ conservation + 2 examples
a method of conservation where species are kept in captivity for later conservation efforts e.g. zoos and botanical gardens
outline how zoos and captive breeding programs allow ex situ conservation of animals
allow individuals of a species to be bred so offspring can be released into the wild , also they allow scientific research, animals genetics, behaviours and habitats can be studies
give 3 disadvantages of zoos
- captive breeding decreases genetic diversity
- some animals will not breed in captivity
- not all zoos can provide adequate habitats for all species
outline how botanical gardens allow the ex situ conservation of plant species
cuttings of plants can be used to obtain large numbers from a small sample size, these can then be reintroduced into habitats
also research can be carried out to study reproduction of plants and allow new habitats to be found if old ones are destroyed
give 1 general advantage + disadvantage of the in situ / ex situ conservation of endangered species
- these methods like zoos, botanical gardens, etc are important for education + awareness
- if a species goes extinct in the wild these conservation efforts aren’t useful
what are modern methods of conserving endangered species
now we can store genetic information / genetic material of endangered species so it isn’t lost forever, e.g. seed banks, frozen zoos
- these store eggs, stern, tissue samples, seeds, etc, ideally collected from many individuals to maintain a large gene pool, in the hopes that some animals can be reintroduced in the future, through IVF or genetic engineering
- remember they will need a habitat to return to, pollution, deforestation, etc are still threats
give 2 methods of conserving areas/habitats
national parks, marine parks
national park definition
areas where wildlife + environment are protected as enforced + controlled by government legislation
give 3 examples of restrictions on human interference in national parks
- human access is strictly controlled
- industrial activities are rightly regulated e.g. agriculture/builing
- hunting is limited or strictly prohibited
marine park definition
protected areas of water which have been set up for the conservation of marine ecosystems + species, and to prevent overfishing
what 3 methods are used to increase the success of national/marine parks
- heavy focus on public engagement
- ecotourism which provides money for conservation efforts
- also allows the education of the importance of the conservation
what is 1 advantage of conservation agreements
these encourage international cooperation, which is essential to conservation
give 4 examples of conservation agreements
CITES
CBD
IUCN
CSS
what does CITES stand for + what is its purpose
convention on international trade in endangered species of wild flora and fauna - a signed deal
- aims to control trade of endangered species + associated products, e.g. elephants + ivory tusks
what is a concern about CITES
as trade becomes illegal, price will increase, which can be a major incentive for people to break the law
what does CBD stand for + what is its purpose
convention on biological diversity - a signed deal
- main goals are conservation of biological diversity, sustainable use of biological resources, fair and equitable sharing of benefits arising from genetic resources
what does IUCN stand for + what is its purpose
international union for conservation of nature - organisation
- they are the global authority on status of natural world + safeguarding
- they asses conservation status of animals + plants
what does CSS stand for + what is its purpose
countryside stewardship scheme - a scheme
- provides funding to farmers + private land owners who use environmental management strategies to increase biodiversity on their land
