Biodiversity Flashcards
Biodiversity
measure of the variation found in the living world
Species
individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics. So can interbreed freely to produce fertile offspring.
Species Richness
number of plant species
Species Evenness
the degree to which species are represented/ how evenly represented the species are (diverse if same amount of each)
Random sampling disadvantages
may not cover all areas of the habitat equally, species with low presence may be missed so underestimate biodiversity.
What is opportunistic sampling?
what are advantages?
what are disadvantages?
researcher makes sampling decisions based on prior knowledge of which areas contain particular species
easier and quicker than random
biased, large or colourful species may attract researcher, so overestimate
What is stratified sampling?
advantages?
disadvantages?
dividing habitat into areas which appear different and sampling each separately.
ensures all different areas are sampled
may over-represent some areas
What are types of systematic sampling?
advantages?
disadvantages?
line transects, belt transects
when habitat shows clear gradient in environmental factors like getting drier further from pond
only species on line or within belt are recorded, so underestimate
What to be careful with when sampling?
not cause disturbance to habitat
What is an interrupted belt transect?
use quadrat at set intervals along line
What is a continuous belt transect?
place quadrat beside line and move along line so study band/belt in detail
6 ways of catching invertebrates
sweep netting (with stout net, empty on white sheet)
pooter (collect animals before fly away)
knock the branch (white sheet under to catch)
pitfall trap (container in soil, contain little water/scrunched paper, in rain should be sheltered)
tullgren funnel (from leaf litter, light above drives animals down as litter dries/warms, fall through mesh to jar)
light trap (UV light attracts, eventually fall into jar containing alcohol)
How to trap small animals
may need license
Longworth trap (human trap, should monitor to release trapped animals)
enables mark-and-recapture technique
total population=no. 1st captured x no. 2nd captured
————————————————–
no. marked captured on 2nd
disadvantage of mark-and-recapture technique
animals may learn that trap is harmless and contains food, or may keep away from traps after first capture
Locus
the position of an allele (version of a gene) on a chromosome
Polymorphic gene locus
a locus that has more than two alleles
Simpson's index of diversity takes into account both... D is.. n is.. N is.. a diverse habitat will have a .. value
species richness and species evenness. D is the letter for it n is the number of individuals of a particular species N is the total number of all individuals high
Isolated populations…
have limited genetic diversity so may need conservation
Genetic diversity is found where…
these is more than one allele for a particular locus
You can calculate genetic diversity by…
calculating the number of loci in one individual that are heterozygous (contain two different alleles)
or percentage of loci in the population that have more than one allele
Monoculture
a crop consisting of one strain of one species
How do humans affect biodiversity?
alter ecosystems to provide us with food
destroy habitats
use Earth’s resources
pollute atmosphere
What happens when we clear natural vegetation and reduce size of habitats?
It reduces population sizes and so reduces genetic diversity. The species is less able to adapt to changing conditions through evolution.
Monoculture is good because… but bad because…
Selective breeding means…
it’s easier to harvest
it has limited genetic diversity
reduction in genetic diversity and other breeds become rare and may die out
Genetic erosion is…
reduction of genetic diversity of a species
Climate change will cause…
migration to a more suitable environment but there are obstructions to the migration like human development, agricultural land, bodies of water and mountain ranges.
Keystone species
has disproportionate effect upon environment relative to its abundance. (has massive effect compared to how much there is of it)
Soil depletion
the loss of soil fertility caused by removal of minerals by continuous cropping
Why is genetic diversity good for us?
genetic diversity of wild species may lead to pharmaceutical products
Economic reasons to maintain biodiversity
What other reason is there?
natural ecosystems: regulate atmosphere and climate purify and retain fresh water form and fertilise soil recycle nutrients recycle waste pollinate crops grow timber, food, fuel provide medicines
also aesthetic reasons - brings people happiness (scientifically proven)
Conservation in situ
carrying out active management to maintain the biodiversity in the natural environment
Ways of carrying out conservation in situ
legislation (stop activities like hunting/clearing land)
wildlife reserves
3 principles for choosing wildlife reserve
comprehensiveness (how many species in area, what env conditions
adequacy (area large enough for long term)
representativeness (full range of diversity within species?)
advantages of in situ
disadvantages
in natural habitat permanent allows management ecologically sustainable land uses - economic benefit research can improve/restore area
habitats fragmented, small area not large for survival
population may already lost genetic diversity
conditions that causes endangered still present
area good for poachers and ecotourists who disturb
Conservation ex situ
and types
outside normal habitat of species
Zoo, Botanic garden, Seed bank
What do zoos do?
breeding endangered species (artificial insemination, IVF, embryo transfer)
conduct research that may benefit species (may research on domestic species/common wild species that similar, to spare endangered species from research)
10 advantages and 9 disadvantages of ex situ
protected from predators and poaching
health monitored, medical assistance
populations divided so disaster doesn’t kill all
genetic diversity measured
selective breeding increases genetic diversity
increase reproductive success
bred to increase numbers
research is easier
attractions to raise funds for conservation
education
captive population limit genetic diversity
exposed to diseases
outside natural habitat
nutritional issues difficult to manage
animals not behave as normal, reproduction difficult
correct env difficult to achieve
expensive
new have to survive reintroduction to wild
reintroduced animals may struggle with acceptance by existing wild members
How do Botanic Gardens work? plus advantages ( seeds storing breeding wild
seeds produced in large numbers and collected form wild without much disturbance
stored (without occupying lots space), germinated in protected place
plants bred asexually and can very quickly increase no.
can replant in wild
Botanic Gardens disadvantages (7)
funding (fewer donations)
collecting causes some disturbance
samples may not have representative level of genetic diversity
seeds from one area may be different to others so not succeed in different place
stored seeds may not be viable
asexual breeding reduces genetic diversity
research maybe not valid for whole species
How are seeds stored in Seed banks?
dry, freezing conditions
check regularly for viability
CITES (The Convention on International Trade in Endangered Species)
international agreement to ensure internatinal trade in specimens of wildlife doesn’t threaten their survival.
stops trade for commercial purposes
less endangered species can trade subject to permit
Rio Convention on Biological Diversity
sustainable use
shared access to genetic resources
sharing of scientific knowledge and technologies (improve chance of success)
fair sharing of benefits from use of genetic resources
The Countryside Stewardship Scheme
encourages landowners to manage land in way that promotes conservation. (funding and advice)
