a level biology > Biodiversity > Flashcards

Biodiversity Flashcards

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1
Q

Biodiversity

A
  • variety of living organisms present in an area
  • includes plants, animals, fungi
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2
Q

why is biodiversity important

A
  • maintaining a balanced ecosystem for all organisms
  • as all species are interconnected
  • therefore they depend on each other
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3
Q

example of why biodiversity is important

A
  • trees provide homes for animals
  • animals eat plants
  • plants need fertile soil to grow
  • fungi/microorganisms decompose dead animals/plants returning nutrients to soil
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4
Q

what do balanced ecosystems provide us with -

A
  • food
  • oxygen
  • materials we need to survive
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5
Q

give examples of human activities which reduce biodiversity

A
  • farming
  • clearing land for housing
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6
Q

which regions of the world have the most biodiversity

A
  • tropical regions all year round
  • regions closest to the Equator
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7
Q

which regions of the world have the least biodiversity

A
  • very cold areas
  • very dry areas
  • Arctic
  • desert
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8
Q

why is measuring biodiversity important

A
  • plays important role in conservation
  • informs scientists of species that are present
  • provides baseline biodiversity level
  • from this effect of changes to an environment can be measured
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9
Q

environmental impact assessment

A
  • taken before major project begins
  • e.g buildings/new roads
  • predicts positive and negative effects of a project on biodiversity in that area
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10
Q

different levels biodiversity can be studied at -

A
  • habitat biodiversity
  • species biodiversity
  • genetic biodiversity
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11
Q

habitat biodiversity

A
  • number of different habitats found within an area
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12
Q

the greater the habitat biodiversity …

A
  • greater species diversity within that area
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13
Q

examples of habitat types in the UK

A
  • meadow
  • woodland
  • streams
  • sand dunes
    = rich habitat biodiversity
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14
Q

species biodiversity

A
  • composed of species richness and species eveness
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15
Q

species richness

A
  • the number of different species living in a particular area
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16
Q

species evenness

A
  • relative abundance of each different species living in a community
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17
Q

genetic biodiversity

A
  • variety of genes that make up a species
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18
Q

what type of gene leads to genetic biodiversity

A
  • alleles
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19
Q

what does genetic biodiversity within a species do -

A
  • lead to different characteristics being exhibited
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20
Q

example of genetic biodiversity

A
  • different breeds of dog
  • have different coat colour and length
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21
Q

greater genetic biodiversity …

A
  • better adaptation to a changing environment
  • more likely to result in individuals who are resistant to disease
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22
Q

why is sampling used

A
  • measure and compare
  • biodiversity of different habitats
  • estimate number of organisms in an area
  • without having to count them all
  • measure a particular characteristic of an organism
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23
Q

sampling

A
  • taking measurements
  • of a limited number of individual organisms
  • present in a particular area
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24
Q

abundance of an organism

A
  • number of individuals of a species
  • present in an area
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25
what can we do after measuring a sample
- use results - to make generalisations / estimates about number of organisms / distribution of species / measured characteristic
26
2 ways of sampling
- random - non - random
27
random sampling
- selecting individuals by chance - each individual in a population has an equal likliehood of selection
28
random sampling - how are organisms selected
- random number tables - computers - experimenter has no choosing in selection
29
example of random sampling - e.g grass verge
- mark out grid on grass using 2 tape measures laid at right angles - use random numbers to determine x and y coordinates on grid - take a sample at each of the coordinate pairs generated
30
non-random sampling
- sample is not chosen at random
31
3 techniques of non-random sampling -
- opportunistic - stratified - systematic
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opportunistic sampling
- weakest form of sampling - uses organisms that are conveniently available
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opportunistic sampling - weakness
- may not be representative of population
34
stratified sampling
- some populations divided into a number of strata (sub groups) based on a characteristic - random sample then taken from each of these strata - proportional to its size
35
e.g of strata
males and females
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systematic sampling
- different areas in an overall habitat are identified - these are then sampled separately - often uses a line/belt transect
37
example - systematic sampling
- may be used to study how plant species change - as you move inland from sea
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line transect
- involves marking a line along the ground - between 2 poles - taking samples at specified points - including describing all organisms which touch the line/distances of samples from line
39
belt transect
- provides more information than line transect - 2 parallel lines are marked - samples are taken of the area between the 2 lines
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why is the sample never entirely representitive of organisms present in a habitat - RELIABILITY
- sampling bias - chance
41
sampling bias
- selection process may be biased - on accident/deliberately - e.g choosing to sample in an area that appears more interesting
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how can sampling bias be reduced
- random sampling - as human involvement in choosing samples is removed
43
sampling weakness = chance -
- organisms selected by chance may not be representative of whole population - can never be completely removed from process
44
how can the chance aspect of sampling be reduced
- using a large sample size - as more individuals studied - so lower probability that chance will influence result - = more reliable
45
how are sampling techniques chosen
- dependent on information you need
46
why is more than 1 sampling technique usually used at each point
- so a range of data is collected
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ethics - animal sampling
- must be handled carefully - for a short time period - must be released back into habitat after being identified/counted/measured at point collected
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pooter
- used to catch small insects - by sucking a mouthpiece - insects drawn into holding chamber - via inlet tube - filter prevents them being sucked into mouth
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sweep nets
- catch insects - in areas of long grass
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pitfall traps
- catch small crawling invertebrates e.g slugs - hole dug into ground - which insects fall into - traps normally left overnight
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features of pitfall traps
- deep so insects cannot crawl out - covered with a roof structure - so trap does not fill with rainwater
52
why are pitfall traps normally left overnight
- to allow nocturnal species to be sampled
53
tree beating
- take samples of invertebrates living in trees/bushes - large white cloth stretched out under tree - tree is shaken/beaten to dislodge invertebrates - animals fall onto sheet where they are studied/collected
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kick sampling
- study organisms living in a river - river bank/bed is kicked to disturb substrate - net held downstream to capture organisms released into water
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how are plants normally sampled
quadrats
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how are animals sampled
- pooter - sweep nets - pitfall traps - tree beating - kick sampling
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quadrat uses -
- pinpoint an area in which sample of plants should be collected - sample slow moving animals, e.g barnacles
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2 types of quadrat
- point quadrat - frame quadrat
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point quadrat
- consists of a frame containing a horizontal bar - at set intervals along bar - long pins are pushed through bar to reach ground - each species of plant that touches pin is recorded
60
frame quadrat
- square frame divided into grid of equal sections - type and number of species in each section - is recorded
61
how can quadrats be used to collect the most valid, representative sample
- random sampling
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how should quadrats be sampled to study whether the presence/distribution of an organism across land area varies
- systematic sampling - along belt/line transect
63
how is species richness measured
- quadrats - sampling animals techniques - compile a list of species identified - calculate
64
example of an evenly distribution of species
- total = 50 - 20 woodlice - 15 spiders - 15 centipedes
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examples of an unevenly distributed species
- total = 50 - 45 woodlice - 5 spiders
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3 main ways to sample population of plants using frame quadrats
- density - frequency - percentage cover
67
density - frame quadrats
- if individual large plants can be seen clearly - count the number of them in 1x1 square Q - = density/square metre - absolute measure
68
frequency - frame quadrat
- used when individual species members are hard to count - use small grids within quadrat to count number of squares a particular species is present in
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percentage cover - frame quadrat
- used for speed - lots of data collected quickly - estimate of the eye of the area within a quadrat - that a particular plant species covers
70
percentage cover - frame quadrats - benefits
- when a particular species is abundant - or difficult to count
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after getting plenty of quadrat samples what do we do
- calculate mean - to get an average value for a particular organism per m2 - to work out total population of organism for an area - multiply mean value per M2
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why may estimating animal population size be difficult
- animals are constantly moving - some may be hidden
73
which technique is used to estimate animal population size
capture - mark - release - recapture
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capture - mark - release - recapture
- capture as many individuals in a species as possible of an area - mark organisms - release organisms back into community - give time for organisms to redistribute themselves - collect another sample - compare number of marked individuals with number of unmarked individuals - greater number of marked individuals = smaller population
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species evenness of an area -
- compare total number of each organism present - populations which are similar in size / density = even community - = high species evenness
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abiotic factors
- non - living conditions in a habitat
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abiotic factors - examples
- light availability - water availability
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why are abiotic factors measured
- to enable scientists to draw conclusions about organisms present - and conditions needed for survival
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wind speed - sensor used
- anemometer - m s-1
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light intensity - sensor used
- light meter - lx
81
relative humidity - sensor used
- humidity sensor - mg dm -3
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pH - sensor used
- pH probe - pH
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temperature - sensor used
- temperature probe - degrees Celcius
84
oxygen content in water - sensor used
- dissolved oxygen probe - mg dm -3
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abiotic factors can be measured quickly and accurately using a range of sensors, why is this useful
- rapid changes detected - human error in taking a reading is reduced - high degree of precision - data can be stored/tracked on computer
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example of calculation used to measure biodiversity
- species diversity - as diversity of species in an area is normally proportional to stability of ecosystem - greater species diversity = greater stability
87
what do the most stable communities have
- large numbers of fairly evenly distributed species - in good sized populations
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pollution - biodiversity
- reduces it - due to harsh conditions
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monitoring biodiversity - importance
- useful tool in successful conservation - good for environmental management
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easiest way to measure biodiversity
- count number of species present - = species richness
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species richness - disadvantages when measuring biodiversity
- does not consider number of individuals present - abundance of each species not considered - as a community dominated by 1/2 species is less diverse than one where several species have similar abundance
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Simpsons index of biodiversity
E (n/N)2
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Simpsons index of biodiversity - strengths
- better measure of biodiversity - considers species richness and evenness
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E
- sum of
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N
- total number of organisms of all species
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n
- total number of organisms of a particular species
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when using Simpsons index of biodiversity which sampling techniques to scientists use to estimate number of species in an area
- quadrats
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Simpsons index of biodiversity - values
- always between 0 & 1
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Simpsons index of biodiversity - 0
no diversity
100
Simpsons index of biodiversity - 1
infinite biodiversity
101
higher number of Simpsons index of biodiversity ...
- more diverse the habitat
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In terms of high biodiversity ... nature of the environment
- relatively benign - not stressful - more ecological niches
103
In terms of high biodiversity ... number of successful species
- a large number
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In terms of high biodiversity ... adaptation of species to environment
- many species live in habitat - often with few specific adaptations to environment
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In terms of high biodiversity ... type of food webs
- complex
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In terms of high biodiversity ... effect of a change to the environment on ecosystem as a whole
- often relatively small effect
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why do habitats with low biodiversity which cannot support a large species diversity contain organisms that are highly adapted to the extreme environment
- these organisms may not survive elsewehre
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why is it important to conserve some habitats with low biodiversity
- to conserve rare species - that may be too specialised - to survive elsewhere
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give an example as to where genetic biodiversity is reduced
- captive breeding programmes
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issues with captive breeding programmes
- individuals may suffer with in-breeding problems
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why do scientists calculate genetic biodiversity of a population of a species
- to monitor health of the population - to ensure populations long - term survival
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how is genetic biodiversity created
- all members of species share same genes - however they have different versions - the differences in these alleles - creates genetic biodiversity within a species - more alleles present .. more genetically diverse the population
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alleles
- different versions of the same gene
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importance of genetic biodiversity
- species with more genetic biodiversity are more likely to be able to adapt to environmental changes - less likely to become extinct - as there are likely to be some organisms within the population that carry an advantageous allele - enabling them to survive in altered conditions
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provide an example which outlines the importance of genetic biodiversity
- if a fatal disease is introduced to a population - organisms will be killed - unless individuals carry resistance to the disease - therefore can re-reproduce - leading to survival of species
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how can genetic biodiversity be increased
- number of alleles in a population must also increase
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how can the number of alleles in a population increase
- mutations in DNA of organism = new allele - interbreeding between different populations
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increasing genetic biodiversity - interbreeding
- when individual migrates from one population - breeds with a member from another - alleles are transferred between the 2 populations - = GENE FLOW
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how do we decrease genetic biodiversity
- number of possible alleles in a population must decrease
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list methods to decrease genetic biodiversity -
- selective breeding - captive breeding programmes - rare breeds - artificial cloning - natural selection - genetic bottlenecks - founder effect - genetic drift
121
selective breeding
- only a few individuals within a population are selected for their advantageous characteristics and bred
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example of selective breeding -
- breeding of pedigree animals - breeding of human food crops
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captive breeding programmes
- only a small number of captive individuals of a species are available for breeding - often the wild population is endangered/extinct - e.g zoos
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rare breeds
- when selective breeding is used to produce a breed of domestic animal/plant - with characteristics which become less popular - so numbers of breed fall - when only a small number of individuals of a breed are selected for specific breed traits - genetic biodiversity of remaining population is low
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issues with rare breeds
- causes problems when trying to restore numbers - yet maintain breed characteristics
126
artificial cloning
asexual reproduction
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artificial cloning - example
- using cuttings to clone a farmed plant
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natural selection
- species will evolve to contain the alleles which code for advantageous characteristics - over time less advantageous coding alleles will be lost from population
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genetic bottlenecks
- few individuals within a population survive an event or change - thus reducing the gene pool - only alleles of surviving members of population are available to be passed down
130
example of an event or change which causes genetic bottlenecks
- disease - environmental change - habitat destruction
131
founder effect
- a small number of individuals create a new colony - geographically isolated from the original - gene pool for new population is small
132
genetic drift
- random nature of alleles being passed from parents to offspring - frequency of occurrence of an allele will vary - sometimes existence of a particular allele can disappear from population
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where is genetic drift more pronounced
- in populations with a low genetic biodiversity
134
how is genetic biodiversity calculated
- measuring polymorphism
135
polymorphic genes
- have more than 1 allele
136
example of a polymorphic gene
- different alleles exist for immunoglobulin gene - determining human blood type
137
most genes are monomorphic -
- a single allele exists for this gene
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importance of monomorphic genes -
- ensures the basic structure of individuals within a species remains consistent
139
calculation for proportion of polymorphic gene loci -
number of polymorphic gene loci/total number of loci
140
loci
- of a gene - refers to he position of the gene on a chromosome
141
greater proportion of polymorphic gene loci...
greater genetic biodiversity within the population
142
human influence on biodiversity
- population growing rapidly - due to medical, hygiene, housing, infrastructure advancements - so people live longer - to create space for more people - humans disrupt ecology of many areas
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what are humans making space for
- housing - industry - farming
144
human factors decreasing biodiversity
- deforestation - agriculture - climate change
145
deforestation
- the permanent removal of large areas of forest - to provide wood for building/fuel - to provide space for roads/building/agriculture
146
agriculture
- increasing amount of land has to be farmed - to feed growing population - resulting in large amounts of land being cleared and planted with a single crop
147
climate change
- release of CO2 and pollutants into atmosphere - from burning of fossil fuels - is increasing global temperatures
148
monoculture
planting a single crop on land
149
other forms of pollutant - resulting in reduction in biodiversity due to humans
- chemical pollution of waterways - improper disposal of waste and packaging = littering = environmental pollution
150
natural causes of deforestation
- forest fires caused by - - lightning - extreme heat - dry weather
151
unnatural causes of deforestation
- deliberate human action - acid rain
152
how is acid rain caused
- pollutants being released into atmosphere - human cause
153
how does deforestation affect biodiversity
- directly reduces number of trees in an area - if only a specific type of tree is felled, species diversity is reduced - reduces number of animal species present in an area - animals are forced to migrate to other areas for survival (may increase biodiversity of neighbouring areas)
154
why does deforestation reduce number of animals in that area
- it destroys their habitat - food source & home - reduces number of other animal species present in turn - by reducing/removing their food source
155
deforestation - what is done now to restore biodiversity
- some areas of forests are now being replaced - however generally only a few commercially viable tree species are planted - so biodiversity is still reduced from its original level
156
agriculture - how is it reducing biodiversity
- farmers only grow a few species of crop/rear a few animal species - farmers only select species based on what gives them high yield - this small selection if only a few species reduces biodiversity of that area
157
which techniques to farmers use on their desired species to be economically viable to maximise food prodution BUT lead to less biodiversity -
- deforestation - removal of hedgerows - using chemicals - herbicides - monoculture
158
farmers - deforestation
- to increase area of land available for growing crops /rearing animals
159
removal of hedgerows
- to enable them to use large machinery to help plant/fertilise/harvest crops - frees up extra land for growing crops - reducing plant species in an area - destroys habitat of some animals
160
use of chemicals - farmers
- pesticides/herbicides - pesticides kill pests that would eat crops - reducing species diversity - as it reduces pest species - and destroys food source of other organsisms
161
herbicides
- used to kill weeds - as they compete with cultivated plants for light, minerals, water - plant diversity reduced - animal diversity reduced to due removal of important food source
162
weeds
any plant growing in an area it is not wanted
163
monoculture
- farms sometimes specialise in the production of only 1 crop - lowering diversity = only 2 species present - relatively few animal species will be supported by only 1 type of plant
164
monoculture - example - oil palm plantations
- leading causes of rainforest deforestation - leading to loss of habitat for endangered species - e.g rhino
165
climate change - facts
- warning trend over last 50yrs is nearly twice for previous 100 yrs - average amount of water vapour has increased since 1980s over land/ocean = increase consistent with extra vapour warmer air can hold - average temperature of global ocean down to 3km deep has increase - ocean has been absorbing more than 80% heat added to climate system = sea level rise - average arctic temperatures have increased almost twice the global average in past 100 yrs - mountain glaciers and snow cover has declined - leading to sea level rise
166
why is the need to produce reliable data important
- despite weight of evidence - casual links can be made
167
global warming
- a rise in the Earths mean surface temperature
168
global warming - evidence
- CO2 levels in atmosphere have increased significantly since industrial revolution - trapping more thermal energy in atmosphere - so scientists believe it is due to human activity
169
if global warming continues how will biodiversity be affected -
- melting of polar ice caps - rising sea levels - higher temperatures and less rainfall - insect life cycles and populations will change
170
melting of polar ice caps
- could lead to extinction of the animals and plant species living there - animals are migrating further to find favourable conditions as their habitat shrinks
171
rising sea levels and thermal expansion of oceans
- flood low lying land - reducing available terrestrial habitats - saltwater would flow further up rivers - reducing habitats freshwater - reducing animals living in river/near areas
172
higher temperatures and less rainfall
- some plant species cannot survive - leading to drought resistant species (xerophytes) being more dominant
173
what would the loss of none drought resistant species lead to
- loss of some animal species dependent on them as a food source
174
insect life cycle and population changes
- insects are key pollinators of many plants - so if range of insects change as they adapt to climate change - it could affect the lives of the plants it leaves behind - extinction ? - insects carry many pathogens - if tropical insects spread - could lead to spread of tropical diseases towards poles
175
if climate change is slow what could happen
- species may have time to adapt - or migrate to a new area - leading to loss of native species - but other species may move into an area - so biodiversity may not be lost, it may just change as species mix
176
reasons for maintaining biodiversity
- aesthetic - economic - ecological
177
aesthetic reasons for maintaining biodiversity
- presence of different animals/plants in environment enriches our lives - natural world provides inspiration - patients recover more rapidly from stress and injury when they are supported by plants and a natural environment
178
presence of different plants and animals enriches our lives - example
- relax on a beach - woodland walk - rainforest visit
179
example as to how the natural environment provides inspiration
- musicians - writers - provides pleasure for others
180
economic reasons for maintaining biodiversity
- levels of long term productivity are higher - soil erosion and desertification may occur - importance of conserving organisms we use to make things - large scale habitat and biodiversity losses mean species with economic importance may become extinct before discovery - continuous monoculture - crops at risk of being destroyed - areas rich in biodiversity are pleasing - greater potential for manufacture of different products - plant varieties needed for cross breeding
181
soil erosion and desertification -
- occurs due to deforestation - reduce country's ability to grow crops - therefore feed people - leading to resource and economic dependence on other nations
182
conserving all organisms that we use to make things -
- non sustainable removal of resources - will lead to collapse of industry in an area - once all raw material is lost - does not become economically viable to continue the industry
183
large scale habitat and biodiversity losses -
- species with economic importance may become extinct before they are discovered - these species may be medically/chemically useful - rich potential sources
184
continuous monoculture -
- results in soil depletion - reduction in diversity of soil nutrients - as the crop takes out the same nutrients from the soil every year and is then harvested - so nutrients cannot be recycled - depletion makes ecosystem more fragile - crops it can support becomes weaker - increasing vulnerability to opportunistic insects/plant competitors/ microorganisms - farmers become more dependent on pesticides / herbicides / fertilisers - to maintain productivity
185
risk to crops being destroyed -
- high biodiversity protects against abiotic stress and disease - when biodiversity is not maintained a change in conditions / disease can destroy crops - can lead to famine / loss of food source
186
areas rich in biodiversity provide a pleasing attractive environment -
- people enjoy - can promote tourism - has economic advantages
187
greater potential for manufacture of different products in future
- products may be beneficial to humans - may make food production more financially viable - may provide cures/disease treatments
188
plant varieties are needed for cross breeding -
- can lead to better characteristics e.g disease resistance / better yield - relatives of cultivated crop plants provide genetic material to aid production of new crops - through genetic engineering scientists can use genes from wild plants/animals to make crops and animals more efficient - reducing land needed to feed people - if wild varieties lost - plants may be more vulnerable to extinction
189
ecological reasons for maintaining biodiversity -
- organisms are interdependent on others for survival - species play a key role in maintaining structure of ecological community -
190
organisms are interdependent on others for survival
- removal of 1 species may effect others - e.g food source may be lost
191
examples as to why organisms need each other - interdependent
- decomposers break down dead plant and animal remains - releasing nutrients into soil - plants use for healthy growth - plants need bees for pollination
192
species play an important role in maintaining structure of ecological community -
- these are known as keystone species
193
keystone species
- have a disproportionately large effect on their environment relative to their abundance
194
keystone species - importance
- affect many other organisms in an ecosystem - determine species richness and evenness in the community - when a keystone species is removed habitat is changed drastically - other species are affected - therefore they are essential to protect
195
how to humans increase biodiversity
- farming - grazing - planting hedges - meadows - forest management - help to change the landscapes, habitats, ecology over uears
196
sheep grazing -
- enables rare species to survive - by maintaining grass at low levels - plantains that caterpillars feed on thrive
197
conservation
- the preservation and careful management of the environment and of natural resources - by conserving the natural habitat, organisms chances of survival are maintained - allowing them to reproduce
198
2 methods of conservation
- in situ conservation - ex situ conservation
199
in situ conservation
within the natural habitat
200
ex situ conservation
out of the natural habitat
201
how are species classified with conservation purposes
- based on their abundance in the wild - extinct - extinct in the wild - endangered - vulnerable
202
extinct
no organisms of the species exists anywhere in the world
203
extinct in the wild
organisms of the species only exist in captivity
204
endangered
a species that is in danger of extinction
205
vulnerable
a species considered likely to become endangered in the near future
206
which group of species to conservation techniques focus on increasing the numbers of
endangered species
207
scientists promote the practice of sustainable development - what is this
- economic development that meets the needs of people today - without limiting the ability of future generations to meet their needs
208
benefits of in situ conservation
- maintains genetic diversity of species - maintains the evolutionary adaptations - that enables a species to adapt continually to changing environmental conditions - preserves interdependent relationships present in a habitat - therefore interlinked species may be preserved
209
example of in situ conservation methods
- wildlife reserves - marine conservation zones
210
once an area is designated as a wildlife reserve what active management techniques may it include -
- controlled grazing - restricting human access - controlling poaching - feeding animals - reintroduction of species - culling / removal of invasive species - halting succession
211
controlling grazing -
- only allowing livestock to graze a particular area of land for a certain period of time - to allow species time to recover - keeping a controlled number of animals in a habitat to maintain it
212
restricting human access -
- not allowing people to visit a beach during the seal reproductive season - providing paths which must be followed to prevent plants being trampled
213
controlling poaching
- includes creating defences to prevent access - issuing fines - remivubg rhino horns
214
feeding animals -
- helps to ensure more organisms survive to reproductive age
215
reintroduction of species -
- adding species to areas that have become locally extinct - or whose numbers have decreased significantly
216
culling / removal of invasive species -
- removing organisms that compete with native species for resources - species that aren't native to the area - species that have negative environment, economic and health effects
217
succession
- a natural process in which early colonising species are replaced over time - until a stable mature population is achieved
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halting succession - benefits
- helps to maintain beautiful habitats for future generations
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example of a marine conservation zone
- Lundy Island
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marine reserves - importance
- vital in preserving species rich areas - e.g coral reef - which are being devastated by non-sustainable fishing methods
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marine reserve - purpose
- to create areas of refuge - within which populations can build up and repopulate adjacent areas
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why are large areas of sea needed for marine reserves
- as the target species often move large distances - or breed in geographically different areas
223
when are ex situ conservation methods normally used
- in addition to in situ measures - ensuring the survival of a species
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examples of ex situ conservation methods
- botanical gardens - seed banks - captive breeding programmes
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botanic gardens
- plant species grown successfully here - species are provided with best resources to grow
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example of how species are provided with the best resources in botanic gardens
- have provision of soil nutrients - sufficient watering - removal / prevention of pests
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weaknesses of botanic gardens
- majority of species are not conserved - many wild relatives of selectively bred crops are not conserved
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why can wild species be useful
- potential source of genes - can contain resistance to diseases - pest/parasite resistance
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seed bank
- gene bank - store of genetic material - seeds stored carefully so new plants may be grown in future - dried and stored at temperatures -20 C - to maintain viability - by slowing down the rate at which they lose their ability to germinate - most seeds can be stored this way
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strengths of seed banks
- seeds estimated to remain viable for centuries - providing back up against extinction for wild plants - so seeds are stored for future reintroduction/research - helping with future breeding / genetic engineering
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why don't seed banks always work
- some seeds die when dried and frozen
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captive breeding programmes
- produce offspring of species - in a human controlled environment - often run by zoos/acquatic centres
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aims of captive breeding programmes
- to create a stable, healthy population of a species - gradually reintroduce these species back into its natural habitat
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what do captive breeding programmes provide animals
- shelter - abundant supply of nutritious food - absence of predators - veterinary treatment - suitable breeding partners
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why is maintaining genetic biodiversity in captive breeding programmes difficult
- only a small number of breeding partners are available - inbreeding problems can occur
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how do captive breeding programmes overcome problems with maintaining genetic biodiversity
- international catalogue is maintained
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international catalogue - use
- has genealogical data on individuals - mating can be arranged to maximise genetic diversity - artificial insemination, embryo transfer, long term cryogenic storage of embryos allow genetic lines to be introduced - without having to transfer animals
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why may some organisms born in captivity not be suitable for release in the wild
- disease - behaviour - genetic races - habitat
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diseases - organism released to wild
- less resistance to local diseases in captive bred populations - new diseases may exist in the wild - captive animals have yet to develop resistance
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behaviour - organism cannot be released to wild
- during reintroduction many organisms, e.g monkeys starved - as they had no concept of having to search for food - domesticated - animals have to learn to do certain things, e.g search for food
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genetic races - releasing captive born animals into wild
- genetic make-up of captive animals can become different from the original - so 2 populations can no longer interbreed
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habitat - reintroducing captive animals back into the wild
- natural habitat must be restored first - if only a small suitable habitat exists - it is likely there are already as many individuals as the habitat can support - introduction of new individuals can lead to stress/tension - fights linked to territory / food
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international union for the conservation of nature (IUCN)
- assist in securing agreements between nations - details current conservation status of threatened animals - countries then work together to conserve these species - established CITES
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convention on international trade in endangered species (CITES)
- regulates international trade of wild plant and animal specimens and their products - requires cooperation to safeguard species from over-exploitation
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Rio convention
- meeting held resulting in agreements between nations
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Rio convention - outcomes
- convention on biological diversity - united nations framework convention on climate change - united nations convention to combat desertification
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convention on biological diversity (CBD)
-requires countries to develop national strategies for sustainable development - ensuring maintenence for biodiversity
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united nations framework convention on climate change (UNFCCC)
- agreement between nations to take steps to stabilise greenhouse gas concentrations within the atmosphere
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United nations convention to combat desertification (UNCCD)
- prevent the transformation of fertile land into desert - reduce effects of drought through programmes of international cooperation
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example of a local conservation scheme
Countryside Stewardship scheme
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countryside stewardship scheme
- offered governmental payments to farmers and other land managers - to enhance and conserve the English landscape - aim to make conservation a normal part of farming and land management practice
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aims - countryside stewardship scheme
- sustaining beauty and diversity of landscape - improving, extending, creating wildlife habitats - restoring neglected land and conserving archaeological and historic features - improving opportunities for countryside enjoyment
a level biology
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