biodiversity Flashcards
3 strands of biodiversity?
ecosystem diversity
species diversity
genetic diversity
species that lack genetic diversity due to isolation/ low population numbers are much more vulnerable to fluctuations due to what 3 factors?
climate change
disease
habitat fragmentation/ destruction
coral within coral reefs provides what to the organisms within the ecosystem?
microhabitats
shelters
bacteria/microorganisms
breeding grounds/ nesting sites
what is a keystone organism?
has a disproportionate effect on other species
many other organisms depend on it for they survival
when was the rio convention on biological diversity?
what else is it referred to as?
1992
earth summit
on what 3 levels does the rio convention on biological diversity consider biodiversity?
1) the range of habitats/ microhabitats within an ecosystem
2)the range of species within each ecosystem
3)the range of genes/alleles within each species
what does the rio CBD encourage?
cooperation between countries and states
encourages each partner to develop a national strategy for conservation and the sustainable use of biological diversity
states that partner states must adopt e situ measure to compliment in situ measures
what is ex situ and in situ conservation
ex situ= out of natural habitat
in situ= in natural habitat
circle of CBD?
conservation of biological diversity
sustainable use of biological diversity
fair and equitable sharing of benefits arising from the utilisation of biological diversity
what is meant by ‘variation’
differences due to genes and the environment
what are the 2 types of variation?
intraspecific variation=differences within a species
interspecific variation= differences between species
population definition
members of the same species living in a habitat
ecosystem definition
all members of all species and their environment (abiotic factors)
species definition
a group of organisms which can interbreed to produce fertile offspring
what are the 3 levels of biodiversity?
ecosystem/habitat biodiversity
species biodiversity
genetic biodiversity
describe ecosystem/habitat biodiversity
the variety of ecosystems in an area OR the variety of habitats within an ecosystem
the higher the ecosystem diversity, the more stable it is and the less likely it is to change
describe species biodiversity
the variety of species within an ecosystem
considered on 2 levels: species richness and species evenness
definition of species richness
the number of different species in an ecosystem
species evenness definition
the relative abundance of each species
disadvantage of lower species evenness
much less stable
more susceptible to chnage
describe genetic biodiversity
the variety of genes in a gene pool for a particular species
(each gene could have multiple alleles, which increases variation in offspring. combination of meiosis (crossing over/ independent assortment) and random fertilisation increasing number of combination of alleles within a population i.e. increasing genetic diversity)
what are phenotypic differences due to?
a combination of genes and environment
gene definition
a sequence of DNA bases that codes for a specific amino acid sequence
do members of the same species have the same or different genes?
they have the same genes but different versions of them (ALLELES)
what is genetic diversity determined by?
the variety and frequency of different alleles in a population
methods used to calculate genetic diversity?
proportion of polymorphic genes
proportion of heterozygous genes
proportion of genes that are homozygous recessive
what is a polymorphic gene?
a gene that has more than 2 possible alleles
what is a heterozygous geen
a gene that has dominant and recessive alleles expressed
proportion of polymorphic genes equation
no. of polymorphic genes
/////////////////////////////////
no. of genes studied
habitat definition
the specific place where an organism lives
which measure of biodiversity is most significant when assessing the health of one ecosystem
species diversity: an ecosystem, containing multiple habitats, should support multiple different species
how can a habitat contain many species but have a low biodiversity?
high species richness
low species evenness
global biodiversity is in decline
explain how human population growth, agriculture and climate change contributes to a decline in biodiversity
HUMAN POP GROWH
need for more agricultural land/ housing
destroys habitats
more waste produced
more pollution produced
damaging ecosystems
specific example (e.g. overfishing)
global biodiversity is in decline
explain how human population growth, agriculture and climate change contributes to a decline in biodiversity
AGRICULTURE
agricultural land has monoculture/lower biodiversity
loss of older/wild type strains
reduced genetic diversity
subject to disease
inability to adapt to changing conditions
altering habitats
specific example (e.g. draining wetlands reduces habitat diversity)
pesticide use
use of fertiliser
nitrate pollution
eutrophication
global biodiversity is in decline
explain how human population growth, agriculture and climate change contributes to a decline in biodiversity
CLIMATE CHANGE
warmer/drier climate
modern strains/species not adapted
migration may not be possible
rise in sea level reduce land area
more frequent flooding affects terrestrial ecosystems
suggest why the number of species identified is likely to be lower than the actual number of species present on earth
organisms mistakenly identified
some species difficult to identify e.g. if microscopic
some species undiscovered due to remote locations/deep ocean
factors taken into account when describing biodiversity of an area
habitat biodiversity
genetic diversity and range of alleles
species diversity
why conservation of a particular species is important
part of a food web that means other species impacted
have a right to existence
beautiful creatures
ecotourism
genetic resource
biodiversity definition
variety of species, genes,habitats within a particular ecosystem
what term describes this pond:
a dynamic environment that is home to a variety of organisms. temp of pond depends on time of year and weather, and this affects the populations of species that live here
ecosystem
true or false: many pathogenic bacteria have become immune to antibiotics
false
categories for reasons to conserve biodiversity
economic (relating to income e.g. ecotourism, medicines)
ecological (feeding relationships e.g. food webs, natural cycles)
aesthetic (looks, beauty)
economic reasons to conserve biodiversity
soil erosions and desertification may occur as a result of deforestation, leading to decreased crop yield
decreased soil fertility as a result of deforestation may lead to greater spending on fertilisers
people visit Masai Mara in Kenya to see gazelles, zebras and wildebeests
GM crop plants can feed a growing population
plants and fungi in rainforests have the potential to provide new cures for diseases
areas rich in biodiversity provides an attractive environment for tourists
aesthetic reasons to conserve biodiversity
the natural environment can provide a more rapid recovery for patients from stress and injury
the presence of plants and animals enriches our lives
natural world provides inspiration for artists, writers and musicians
ecological reasons for biodiversity conservation
monoculture can reduce the genetic diversity of crop species, reducing their tolerance to disease and environmental change
some species are keystone species, and have a disproportionate effect on the ecosystem, including disrupting N and C cycles
plant varieties are needed for cross-breeding, which can lead to better characteristics such as disease-resistance and greater yield
if wild plants are lost, the crops become more vulnerable to extinction
all organisms are interdependent on each other, so removal of one species may have a significant effect on another
2 examples of in situ conservation
wildlife reserves
marine conservation zones
2 examples of ex-situ conservation
zoos
botanic gardens
describe wildlife reserves
no human access (except park rangers)- acts to limit activity e.g. poaching
animals are fed manually
reintroducing species to their natural habitat (from ex-situ)
culling of species of certain organisms
allow species to graze- prevents ecological succession
describe marine conservation zones
restricting and monitoring fishing practices
restricting visiting policies- bans on commercial boast: particularly during breeding seasons
protected areas within zone which allow breeding- may also selectively breed fish species to boost species
describe zoos
captive breeding programmesL highly controlled artificial selection: can help to increase genetic diversity of a population so when reintroduced, the population is more adaptable to change
DANGER= when reintroduced, species have no basic survival instinct and are susceptible to competition form other members of same species
describe botanic gardens
provide optimum conditions for plant species to grow, as well as optimum nutrition e.g. concentrations of mineral ions
glasshouses provide a lack of herbivores and a lack of pests. compared to their natural environment, this is unrealistic
pests can invoke economic damage and can cause disease
advantages of in-situ conservation
plants/animals are conserved in their natural environment
it permanently protects biodiversity & representative examples of ecosystems
permanently protects significant elements of natural and cultural heritage
allows management of these news to ensure that ecological integrity is maintained
facilitates scientific research
disadvantages of in-situ conservation
endangered habitats may be fragmented, and each small area may not be large enough to ensure survival
the population may already have lost much of its genetic diversity
area can act as ‘honeypot’ to poachers and ecotourists, who inadvertently cause disturbance
conditions that caused habitat or species to become endangered may still be present
advantages of ex-situ conservation
organisms are protected from predation/poaching
health of individuals can be monitored so medical assistance can be given as required
genetic diversity of a population can be measured
selective breeding can be carried out to increase genetic diversity
animals/plants can be bred to increase numbers of an endangered species
conservation sites can be used for education & as attractions to raise funds for further conservation efforts incl. fundraising for iconic animals species e.g. pandas
disadvantages of ex-situ conservation
a captive population is likely to have limited genetic diversity
animals can be exposed to a wide range of diseases
organisms living outside of natural habitat
nutritional issues can be difficult to manage
correct environmental conditions for survival may be difficult to achieve or expensive
even if reproduction successful, animals must survive reintroduction to wild, need to find food and survive predation
when reintroduced, there can be difficulties with acceptance by existing wild members of species
what are seed banks?
a type of gene bank: they store a wide variety of plant species in seed form, in a temperature-controlled environment
why are seeds in a seed bank collected from a variety of different sites?
to ensure a large genetic diversity
advantage of a seed bank if a plant species goes extinct?
seed bank is able to grow this species again from seed, and reintroduce it back to its natural habitat
example of seed bank
Millennium Seedbank at Wakehurst
advantages of a seedbank
cheaper to store seeds, compared to fully grown plants
seeds take up less space than fully grown plants, so more can be stored
seeds are less vulnerable to disease, natural disaster, extreme weather e.t.c.
disadvantages of a seed bank
if seeds are stored for a long time, they may lose viability i.e. the may lose the ability to germinate
expensive and time-consuming to test seeds for viability
challenging to collect seeds from plants in remote environments, or environments that have been subject to forest fires
purpose of IUCN
assesses the status of many of the world’s species of animal and plant
aims of CITES?
regulating and monitoring international trade in selected species of plants and animals
ensuring that international trade does not endanger the survival of populations in the wild
ensuring that trade in artificially propagated (cloned) plants is allowed, subject to permit
they are principally concerned with conservation, sustainable use of resources, and trade, subject to permit
possible sources of animal DNA
blood
saliva
ivory
urine
faeces
bone
what does CITES stand for?
convention on international trade in endangered species
possible benefits of registration with CITES for the conservation of a species
ban on sale of ivory
ban on hunting
increased awareness and education
economic advantage to host country
allow populations to recover
international markets fall below desired price
main priority of countryside stewardship scheme?
to protect and enhance the natural environment, in particular:
increased biodiversity, improved habitat and expanded woodland areas
improved water quality
improved air quality
other outcomes supported are:
protection against flooding/coastal erosion
maintaining historic environment
improved landscape character
climate change adaptation and mitigation
what does a higher value in diversity indices indicate?
that an ecosystem is more stable and robust and is better able to adapt to a changing environment
what values is simpsons index of biodiversity between?
0 and 1
1=infinitely diverse
what is n in simpsons diversity index
number of individuals of a particular species
what is N in simpsons biodiversity index
total number of all species
how is climate change linked to biodiversity
more extreme weather threats biodiversity e.g. Australia bush fires 2019/20 destroyed 97000km^2 of forest, 3 billion animals killed or displaced
cold temps can force organisms to adapt and those who don’t die=force natural selection
global warming alters ecosystems over long periods of time by changing what can grow and live within them e.g. less water vapour in atmosphere= more browning and less growth rates
rising ocean temps affect marine organisms e.g. corals are vulnerable to heat and acidification
species forced out of habitats, those who cannot migrate may become locally extinct e.g. plant/insect species
loss of biodiversity e.g. trees, soils, peatlands are huge carbon sinks and sequester carbon, slowing CC
POSITIVE FEEDBACK LOOP: carbon released=high temps=drier forests/wildfires=carbon released
factors affecting biodiversity
deforestation
destruction of coral reefs
destruction of sea bed
over exploitation
over hunting
agriculture
pollution form agriculture
extreme weather
deforestation
causes
effects
clearing for agriculture/industry/housing
loss of species (decreases species diversity) and loss of resources to rebuild number of species; habitat destruction (loss of habitat diversity)
destruction of coral reefs
causes
effects
farming, fishing, leisure
loss of species (decreases species diversity) and loss of resources to rebuild number of species; habitat destruction (loss of habitat diversity)
destruction of sea bed
causes
effects
dragnets (trawling) scrape the sea bed
loss of species (decreases species diversity) and loss of resources to rebuild number of species; habitat destruction (loss of habitat diversity)
overexploitation
causes
effects
removal of timber for industry or furniture, overfishing so fish stock falls
reduction in number of species and habitat destruction (link to year 2 sustainable timber and fishing)
overhunting
causes
effects
removal of wild animals as “bush meat”
species at risk of extinction
agriculture
causes
effects
monoculture of one type of crop or livestock
reduction in the number of a particular species decreases species evenness
pollution from agriculture
causes
effects
waste products; use of fertilisers and pesticides (bioaccumulation)
loss of species diversity as some species thrive with the additional fertilisers and others are destroyed (eutrophication); runoff pollutes streams and pond water
extreme weather
causes
effects
modification of weather patterns e.g. droughts and floods affects species distribution
distribution of species changes (migration patterns); lack of food for some species causes decline (extinction)
describe the difference between a pioneer community and a climax community
pioneers arrive before climax
pioneers=subject to greater/more change
lower biodiversity, less stable and lower biomass
climax community is final stable seral stage
why is it sometimes necessary to conserve a plant species ex situ
low numbers
reproduction more difficult in the wild
protection form pathogens
protection form herbivores
breed plants selectively and maintain gene pool
may be vulnerable to habitat destruction
advantages of conserving plant species as seeds and not adult plants
take up less space so larger numbers can be stored
lower maintenance costs required
less susceptible to disease
store greater genetic diversity
cheaper to transport
remain viable for long period of time
factors to be considered when selecting individuals for breeding programme
of reproductive age
individuals of opposite sex
unrelated
higher proportion of females
healthy
how to ensure success of release programme
protected zone established to prevent habitat destruction
educate local population
track/monitor female’s activity
healthy before release
food supply
prepare animals for survival in wild
gradual introduction via semi-wild habitat
