4.2 Biodiversity Flashcards
What is the difference between species richness and species evenness?
(species) richness is number of species (in a habitat) ;
(species) evenness is , abundance / number of
individuals of , each / every / all , species (in a habitat)
What are the four types of sampling?
Random
Oppertunistic- prior knowledge
Stratified- broken up
Systematic- regular intervals
Define biodiversity
range / variety / number , of species (in an area) ;
range / variety of, habitats / ecosystems ;
variety of , alleles / genes ;
define species
organisms that can freely interbreed to produce fertile offspring
what are the 3 types of biodiversity?
habitat
species
genetic
what is habitat biodiversity?
the range of habitats in which different species live
what is species biodiersity?
Difference between species
This could be within a habitat, or a community
Differences could be structural or physical
what is genetic biodiversity?
variation between individuals belonging to the same species
What is habitat sampling (2)
small portion of a habitat is selected and studied carefully.
You can then multiply up the numbers of individual species found to give an estimate for the entire habitat.
what is random sampling
randomly select sample sites by randomly generate numbers as coordinates
what is one advantage and one disadvantage of random sampling?
ensures data isn’t biased
may not cover all areas equally
what are the 3 types of non-random sampling?
oppertunistic
stratified
systematic
what is oppertunistic sampling?
decides sample based on prior knowledge of the habitat
what is one advantagr and one disadvantage of oppertunistic sampling?
easier and quicker than random
may be biased
what is stratified sampling?
dividing habitat into areas that appear different and sampling each area
what is one advantagr and one disadvantage of satrtified sampling?
ensures all different areas are sampled
may lead to over representation of
what is systematic sampling?
samples are taken at fixed intervals across habitat (line/belt transects)
what is one advantage and one disadantage of systematic sampling?
useful when habitat shows gradient
some species may be missed
Sweep netting is a technique used to catch invertebretes. How is thhis done?
sweep net through vegitation
small animals will be caught in net
empty them onto white sheet to identify them.
what is a pitfall trap?
small container buired in soil containing little water or scrunched paper to stop animals crawling out again
what is a light trap?
uv light attracts insects who eentually fall into the alcohol at bottom
what does simpsons index of diversity measure?
diversity of a habitat takin into accountspecies richness and evenness
What is the formula for species index of diversity?
d= (sum (n/N)^2)
What 4 things affect biodiversity?
human population growth
agriculture
cllimate change
extinction
how does human popluation growth affect biodiversity?
we alter ecosystems to get fppd
we destroy habitats
we pollute atmosphere
how does agriculture affect biodiversity?
monoculture (crop consisting of one strain of species) has very limited genetic diversity
what are the 3 sets of reasons to maintain biodiversity?
ecological
economic
aesthetics
What is the ecological reason to maintain biodiversity? 3
1) individuals are interdependent upon each other for survival in food chains
2) keystone species are individuals that have a disproportionate
impact on a habitat and its biodiversity
3) if biodiversity declines, genetic diversity declines,
What are 4 of the economic reasons to maintain biodiversity.
reducing soil erosion/depletion
reducing the mineral depletion that occurs in monoculture
sustainability – using natural resources without their loss
avoiding the loss of potentially economically valuable species
avoiding the rapid spread of disease seen in monoculture
promoting tourism to an area
giving greater potential for the manufacture of products
giving greater genetic diversity that could be useful in genetic
engineering
What is the aesthetic reason to maintain biodiversity?
providing beautiful environment for people to live in
it would be wrong to destroy natural beauty
What is conservation in situ?
arrying out active management to maintain the biodiversity in the natural environment
What is conservation ex situ?
conservation outside the normall habitat of the species
state 2 advantages of conservation in situ.
conserved in natural environment
permanenly protects biodiversity
improve and restore ecological integrity
state 2 disadvantages of conversation in situ.
habitat may be fragmented so areas not large enough to ensure survival.
may have already lost most of its genetic diversity
may attract poachers/tourists causing disturbance
state 2 advantages of conservation ex situ.
protected from predator and poaching
health monitored and medical assistance
populations can be divided so if disasted strikes one, the other will survive.
selective breeding
bred to increase numbers of endangered species
attractions to raise funds for further conservation
education
give 2 disadvantages of onservation ex situ
limited genetic diversity
exposed to many diseases
living outsie natural habitat
dont behave as normal
difficult to achieve correct environmental conditions
expensive to achieve correct environmental conditions
have to survive reintroduction to wild
difficulties with acceptance from preexisting wild members of species
Give 2 advantages of botanic gardens.
seeds are produced in large numbers so can be collected without disturbing population
protected surroundings
dont occupy much space to store
stored/germinated in protected surroundings
can be replanted in wild
Give 2 disadvantages of botanic gardens
funding is difficult
collectin wild seeds causes some disturbance
samples wont have representive genetic diversity
stored for too long wont be viable
asexual breeding will be genetically identical so low genetic diversity
research on small sample maybe not valid for whole species
What does CITES do?
Regulate trade in selected species
Encourage trade does not endanger species
Permits enforced for trade of less endangered species
Allow trade for artificially propagated plants
Explain the importance of sampling in measuring the biodiversity of a habitat. (2)
impossible / difficult , to count every individual ;
sample provides an estimate ;
sample representative (of whole area) ;
Why do we need to measure both richness and evenness to assess biodiversity?
idea that both (richness and evenness) are needed to
reveal dominance ;
idea that high biodiversity associated with high species
richness and high species evenness ;
Explain why it is sometimes necessary to conserve a plant species (3)
(natural) habitat / ecosystem , lost due to / destroyed
by / under threat from , climate change /
(named) human activity ;
number / population , (in natural habitat) is very low ;
idea that in the wild, (sexual) reproduction is difficult (if
numbers are low) ; ora
(breeding ex situ can) maintain , the gene pool /
genetic / allelic , diversity; ora
idea that allows protection from , grazers / herbivores
/ plant collectors / competing species ; ora
idea of protection from ,
pathogen / parasites / disease ; ora
Give 3 advantages of conserving plant species as seeds and not as adult plants.
can be collected with minimal damage to (wild) ,
population / habitat / ecosystem ;
take up little space / larger numbers can be stored ;
can store great(er) , genetic / allelic , diversity
low(er) maintenance / manpower costs /
easy / cheaper, to transport /
idea of remaining viable for long periods
less , susceptible / vulnerable , to, disease / pests /
environmental change ;
Idea that prevents fertilisation by undesired pollen ;
Outline the implications for a habitat if the Simpson’s Index of Diversity is low. (2)
(habitat) dominated by, one / few / AW, species ;
change in one species , likely to affect whole
habitat / AW ;
community / ecosystem / habitat / area , is
unstable / not able to withstand change /
easily damaged ;
