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Biodiversity Flashcards

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1
Q

What is biodiversity?

A

Biological variety of organisms living in an area

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2
Q

What is a population?

A

Number of all the organisms of the same species living in a particular geographical area at the same time

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3
Q

What is a community?

A

All the populations living in a particular geographical area at the same time

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4
Q

What is habitat biodiversity?

A

Number of habitats found in an area

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5
Q

What are the two methods to measure species biodiversity?

A
  • Species richness

- Species evenness

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6
Q

What is species richness?

A

Number of different species in an area

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7
Q

What is species evenness?

A

Comparison of the size of each population in an area

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8
Q

What is genetic biodiversity?

A

Number of genes and alleles that are present in the genetic material of a species

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9
Q

Why is high genetic biodiversity beneficial?

A

Greater genetic biodiversity leads to a greater chance of adapting to selection pressures and survival of a species

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10
Q

How can you measure biodiversity?

A

Use sampling techniques by counting or measuring a limited number of individuals

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11
Q

What should sampling be?

A
  • Unbiased
  • Representative of an area
  • Not time consuming
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12
Q

What is random sampling?

A
  • Individual organisms are selected by chance
  • If it is strictly random then the same individual may be counted more than once
  • Random number tables and coordinates are used to place quadrats
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13
Q

What is non-random sampling?

A
  • Individual organisms are purposefully selected
  • Can be one of three types of non-random sampling:
    1. Opportunistic
    2. Stratified
    3. Systematic
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14
Q

How to carry out random sampling?

A
  1. Mark out a grid on grass using two tape measures laid at right angles
  2. Use random numbers to determine the x and y coordinate on your grid
  3. Take a sample at each of the coordinate pairs generated
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15
Q

What are the three types of non-random sampling?

A
  1. Opportunistic sampling
  2. Stratified sampling
  3. Systematic sampling
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16
Q

What is opportunistic sampling?

A
  • Counting visible organisms at a given time e.g. counting birds in the garden that feed on the bird feeder outside your window
  • Weakest type of sampling and not representative of population
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17
Q

What is stratified sampling?

A
  • An area or population can be divided into groups (strata)
  • A proportionate number of observations is taken for each part of the population
  • Random samples are then taken from these strata but in proportion to the size of the strata
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18
Q

What is systematic sampling?

A
  • Where observations are taken at regular intervals
  • For example, a quadrat placed every 10m along a line running from seashore inland across a beach
  • Systematic sampling may sample different areas within the same geographical area, but they are sampled separately and the samples will not be in proportion to the size of the geographical area
  • Is often done in the form of a line transect or a belt transect
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19
Q

What is a belt transect?

A

Where two parallel lines are marked out and samples are taken of the area between the two lines

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20
Q

What is a line transect?

A

Marking a line along the ground between two poles and taking samples at specified points, this can include all the organisms touching the line or distances of samples from the line

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21
Q

Why is a sample not entirely representative of the organisms in a habitat?

A
  1. SAMPLING BIAS
    - selection process is biased (accidently or purposely)
    - you see an area with lots of plants
    - this bias can be reduced by random sampling
  2. CHANCE
    - organisms selected by chance may not be representative of the whole population
    - e.g. five woodlice in a sample may have been, by chance, the five largest woodlice in the habitat and hence unrepresentative of the population
    - effect of chance can be reduced by using a large sample size
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22
Q

What is a pooter used for and how does it work?

A
  • Used to catch small insects
  • By sucking on a mouthpiece, insects are drawn into the holding chamber via the inlet tube
  • Filter before mouthpiece prevents them from being sucked into the mouth
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23
Q

What are sweepnets used for?

A

-Used to catch insects in areas of long grass

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24
Q

What are pitfall traps used for and how do they work?

A
  • Used to catch small, crawling invertebrates such as beetles, spiders and slugs
  • Hole is dug into ground which insects fall into
  • Must be deep enough so they can’t crawl out and covered with a roof structure
  • Traps left overnight so nocturnal species are also sampled
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25
Q

What is tree beating and how does it work?

A
  • Use to take samples of invertebrates living in a tree or bush
  • Large white cloths are stretched out under the tree
  • Tree is shaken or beaten to dislodge the invertebrates
  • Insects fall onto sheet where they can be collected and studied
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26
Q

What is kick sampling and how does it work?

A
  • Used to study organisms living in a river
  • River bank and bed is kicked for a period of time to disturb the substrate
  • Net is held just downstream for a period of time in order to capture any organisms released into the flowing water
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27
Q

What is the Tullgren Funnel and how does it work?

A
  • Used to extract living organisms, especially arthropods from samples of soil
  • Creates a desiccation gradient over the sample such that mobile organisms will move away from the dry environment and fall into a collection vessel
  • Here, they will perish and are preserved for examination
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28
Q

What are light traps and how do they work?

A
  • Insects are lured by light and become trapped into the collecting chamber
  • Secure poles into the ground, mount the lights on the pole 5m above the ground
  • Used to collect flying insects
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29
Q

How are point quadrats used to sample plants?

A
  • Consists of a frame containing a horizontal bar
  • At set intervals along the bar, long pins can be pushed through to reach the ground
  • Each species of plant the pin touches is recorded
30
Q

How are frame quadrats used to sample plants?

A
  • Consists of a square frame divided into a grid of equal sections
  • Type and number of each species within each section of the quadrat is recorded
31
Q

What are the three ways frame quadrats can be used?

A
  1. Density
  2. Frequency
  3. Percentage cover
32
Q

How can frame quadrats be used to measure density?

A
  • If individual large plants can be seen clearly, count the number of them in a 1mx1m quadrat
  • This will give you the density per square metre
  • This is an absolute measure, not an estimate as the following two methods
33
Q

How can frame quadrats be used to measure frequency?

A
  • Used where individual members of a species are hard to count (grass/moss)
  • Using the small grids within a quadrat, count the number of squares a particular species is present in
  • For example, if clovers are present in 65 out of 100, the frequency of its occurrence is 65%
34
Q

How can frame quadrats be used to measure percentage cover?

A
  • Used for speed as lots of data can be collected quickly
  • Useful when a particular species is abundant or difficult to count
  • It is an estimated by eye of the areas within a quadrat that a particular plant species covers
35
Q

What is Simpson’s Index of Biodiversity?

A

-Measure of biodiversity that combines the concept of species richness and species evenness

36
Q

What is genetic biodiversity?

A

Total number of genes and their alleles in the genetic material of a species

37
Q

What is the genetic diversity of a population usually referred to as?

A

Gene pool

38
Q

Why is high genetic diversity important?

A

More genetic diversity increases the likelihood that some individuals in a population will possess alleles that are more suited for their environment
Hence, the population will continue for more generations because of the success of these individuals

39
Q

What factors increase genetic biodiversity?

A
  1. Mutations to create new alleles

2. Gene flows

40
Q

How do mutations increase genetic biodiversity?

A

Mutations increase the number of alleles that are present in a population

41
Q

How does gene flow increase genetic biodiversity?

A
  • Gene flow is the transfer of genetic material from one population to another
  • Migrants change the distribution of genetic diversity among populations by modifying allele frequencies
42
Q

What factors decrease genetic biodiversity?

A
  1. Selective breeding
  2. Captive breeding programmes
  3. Rare breed and pedigree programmes
  4. Artificial cloning
  5. Natural selection
  6. Genetic drift
43
Q

How does selective breeding decrease biodiversity?

A
  • Process by which humans use animal and plant breeding to selectively develop particular phenotypic traits by choosing which males and females will sexually reproduce and have offspring
  • Decreases genetic diversity by reducing the number of alleles in the gene pool so that all members of the breed have the same characteristics
44
Q

How do captive breeding programmes decrease biodiversity?

A
  • Keeping animals or plants in a controlled environment is an example of the founder effect
  • They are often employed to help species that are under threat
  • By taking individuals from a population , you are reducing the number of the alleles in both groups, hence decreasing genetic biodiversity
  • However, they can save a species from extinction
45
Q

How do rare breeds and pedigree programmes decrease genetic biodiversity?

A

-A rare breed is a breed of poultry or livestock that has been selectively bred and have a very small breeding population (hundred to thousand)
-This is an example of a genetic bottleneck
-There are very few alleles present in the breeding population
-The same thing occurs with pedigree animals, who are breeds that is also selectively bred and actively maintained by an organisation e.g. The Kennel Club
-However, rare breeds do have unique alleles and can
be a source of future alleles and therefore could be a source of genetic diversity

46
Q

How does artificial cloning decrease genetic diversity?

A
  • Cloning is the process of producing individuals with identical or almost identical DNA
  • In nature, many organisms produce clones through asexual reproduction
  • In agriculture, cloning is used for monoculture of cash crops
  • Artificial cloning increases the size of a population but cloned organisms are all genetically identical so this decreases genetic biodiversity
47
Q

How can you quantify the amount genetic biodiversity in a population?

A
  • Polymorphism is when there is more than one form or form for a characteristic
  • E.g. the dark morph of the jaguar is the panther and the light morph is known as the jaguar
  • Alternatively, it is when there is more than one allele for a gene that give rise to different phenotypes
48
Q

How can you calculate the proportion of polymorphic genes?

A

total number of loci

49
Q

What is loci?

A
  • Loci (plural of locus) is the geneticist term for a gene

- It refers to the position of the gene on the chromosome

50
Q

What is the relationship between proportion of polymorphic loci and genetic diversity?

A

The greater the proportion of polymorphic loci, the greater the genetic diversity

51
Q

Why is low genetic biodiversity a negative?

A
  • Less chance of an individual to have an allele for an advantageous characteristic for its environment
  • Therefore species is less likely to be successful for generations
  • It also reduced resistance to disease, especially in crops
52
Q

What factors affect biodiversity?

A

-Deforestation
-Agriculture
-Climate change
All partly caused by human population growth

53
Q

How does deforestation affect biodiversity?

A
  • Caused naturally by forest fires, but most commonly due to human action
  • Areas of forest been destroyed either by directly cutting them down or due to acid rain from pollution
  • Reduces number of trees in an area
  • If only one specific type of tree is felled, the species diversity is reduced
  • Reduces number of animal species in an areas as it destroy their habitat and their food source
  • It can also disturb animals causing them to migrate out of an area
  • Or they are forced to migrate to other areas to ensure their survival
  • Often only commercially viable trees are replanted so biodiversity isn’t every fully restored
54
Q

How does agriculture affect biodiversity?

A
  • Farmers will only grow a few different species of crop plants or rear just a few species of animal
  • Species selected based on high yields and desirable characteristics
  • Selection of only a few species reduces biodiversity in an area
  • Monoculture often used where many acres of land are used to grow one species
  • Reduces number of animal species that can be supported by these crops
  • Palm oil production terrible for deforestation and monoculture
  • Pesticides and herbicides reduce biodiversity and remove food sources for other species, as well as herbicides
  • Removal of hedgerows destroys habitat of animals such as blackbirds, hedgehogs, mice and many invertebrates
55
Q

How does climate change affect biodiversity?

A
  • Melting of polar ice caps could lead to the extinction of the rare, few species living in these areas
  • Animals in the Arctic are migrating further North to find favourable conditions
  • Rising sea levels will destroy low lying islands and coastal regions, reducing the available terrestrial habitats
  • Saltwater would flow further up rivers, reducing habitats for freshwater plants and aquatic animals
  • Higher temperatures and less rainfall would result in some plant species failing to survive, leading to drought resistant crops (xerophytes) becoming more dominant
  • Loss of non-resistant species will affect loss of some animal species dependent on them for survival
  • Insect life cycles and populations will change as they adapt to climate change
  • Insects are key pollinators and their migration could leave many plant species behind, causing extinction
  • Insects also carry many plant and animal pathogens so if tropical insects spread, there would be a spread of tropical diseases towards the poles
56
Q

Aesthetic reasons for maintaining biodiversity:

A
  • Presence of different plants and animals in our environment enriches our lives
  • Natural world provides inspiration for people, such as musicians and writers
  • Studies have shown that patients suffering from stress and injury recover more rapidly when supported by a natural environment
57
Q

Economic reasons for maintaining biodiversity:

A
  • Soil erosion and desertification due to deforestation and climate change can reduce a country’s ability to grow crops and feed its people, which can lead to resource and economic dependence on other nations
  • Non sustainable removal of resources will eventually lead to collapse of that industry in an area
  • Timber production and mining needs to be done sustainably
  • Large scale habitat and biodiversity loss means species may be destroyed before we even see their economic or social potential, especially in rainforests for medicines
  • Monoculture results in soil depletion, a reduction in the diversity of soil nutrients
  • This will lead to a greater reliance on fertiliser, herbicides and pesticides which can all come at a great cost
  • High biodiversity protects against abiotic stress and disease
  • Irish potato famine caused due to pathogen infection which affected the only two varieties of potato in the region
  • Lead to widespread famine which killed around 1million people in 1840s
  • Areas with high biodiversity attract tourism
58
Q

Ecological reasons for maintaining biodiversity:

A
  • All organisms are interdependent on one another, the removal of one species may have a significant effect on others e.g. a food source or pollination
  • Decomposers break down dead plant and animals matter into nutrients that can be used by plants for growth, bees are important pollinators
  • Keystone species have a disproportionately large effect on their environment relative to their abundance
  • They affect many other organisms in an ecosystem and help to determine species richness and evenness
  • Removal of keystone species means other species will be affected and some may disappear altogether
  • Plant varieties needed for cross breeding and as a future source of genetic biodiversity
  • Wild relatives of crop plants provide an invaluable source of genetic material to aid production of new, more resistance varieties of crop, hoping to take up less land
  • If wild varieties are lost, crop plants themselves become more vulnerable to extinction
59
Q

What is in situ conservation?

A

Conservation within the natural habitat

60
Q

What is ex situ conservation?

A

Conservation out of the natural habitat

61
Q

In situ conservation:

A
  • Maintains genetic diversity
  • Maintains evolutionary adaptations that enable a species to adapt continually to changing environmental pressures
  • Preserves interdependent relationships
  • Generally cheaper than ex situ
  • Take form of wildlife reserves or marine conservation zones
62
Q

Wildlife reserves:

A
  • Ex situ conservation
  • Area under active management
  • Controlled grazing
  • Restricting human access e.g. during breeding season to prevent disruption or providing paths to prevent plant trampling
  • Feeding animals to help ensure more organisms survive to reproductive age
  • Controlling poaching, including creating defences, issuing fines or more drastic steps like removal of rhino horns
  • Reintroduction of species
  • Culling or removal of invasive species to reduce competition with native species for resources
  • Halting succession by controlled grazing, controlled burning so native species aren’t outcompeted by new, developing ones
63
Q

Marine conservation zone:

A
  • Vital in preserving species rich areas such as coral reefs
  • Aim not to prevent fisherman from visiting the entire area, but to create areas of refuge where populations can build up and repopulated adjacent areas
  • Large areas of sea are require for marine reserves as the target species often move large distances, or breed in different geographical areas
64
Q

Ex situ conservation:

A
  • Involves removal of organisms from their usual habitat

- Includes botanic gardens, seed banks and captive breeding programmes

65
Q

Botanic gardens:

A
  • Plant species can be grown successfully in botanic gardens
  • Species are actively managed to provide them with the best resources to grow, such as as the provisions of soil nutrients, sufficient watering and removal of pests
  • There are roughly 1500 botanic gardens worldwide, holding 35000 plant species
  • Majority of the species are not conserved
  • Wild relatives of selectively bred crop plants are under represented amongst the conserved species
  • Wild species are a potential source of genes, conferring resistance to diseases, pests and parasites
66
Q

Seed banks:

A
  • Example of a gene bank, a store of genetic material
  • Seeds are carefully stored so that new plants may be grown in the future
  • Dried and stored at temperatures of -20*C to maintain their viability, by slowing down the rate at which they lose their ability to germinate
  • It is expected that they will remain viable for centuries, providing a back up against the extinction of wild plants
  • One vault in Norway houses 800,000 species
  • Plan is to have 3million different types of seeds
  • Storing seeds for future reintroduction, research and genetic engineering in the future
  • Technique doesn’t work for all seeds, especially many tropical plants which could cause an issue for plant species that provide chemicals for vital medication
67
Q

Captive breeding programmes (zoos):

A
  • Produce offspring of species in a human controlled environment
  • Often run and managed by zoos and aquatic centres
  • Several species are now solely represented by animals in captivity
  • Aim to create a stable, healthy population of a species then gradually reintroduce that species back into its natural habitat
  • Arabian Oryx was extinct in the wild before its reintroduction
  • Provide animals with shelter, an abundant supply of nutritious food, an absence of predators and veterinary treatment
  • Suitable breeding partners or AI can be imported from other zoos if not available within zoo’s own population
  • Low genetic diversity due to small set of breeding partners and problems related to inbreeding can occur
  • Some organisms in captivity may not be suitable for release because: loss of resistance to local diseases in captivity, or new diseases may have developed that animals lack resistance to, lack of learned behaviour can cause animals to lack survival skills such as how to find food, genetic makeup of captive animals becomes too different from wild population so can no longer breed and if a habitat is damaged competition would be too great if new animals were released
68
Q

The Rio Convention:

A
  • 1992 historic meeting of 172 nations
  • Held in Rio de Janeiro
  • Became known as the earth summit
  • Resulted in some new agreements:
  • Convention of Biological Diversity requires countries to develop national strategies for sustainable development
  • United Nations Framework Convention on Climate Change is an agreement between nations to take steps to reduce GHG emissions
  • United Nations Convention to Combat Desertification aims to prevent transformation of fertile land into desert to reduce the effects of drought through programmes of international cooperation
69
Q

Countryside Stewardship Schemes:

A

-Many conservation schemes set up at a more local level
-Scheme operated from 1991-2014
-Offered governmental payments to farmers and other land managers to enhance and conserve the English landscape
-General aim was to make conservation a part of normal farming and land management practise
Specific aims included:
-Sustaining diversity and beauty of landscape
-Improving, extending and creating wildlife habitats
-Restoring neglected land and conserving archaeological and historic features
-Improving opportunities for countryside enjoyment
-Now replace by other scheme that operate similarly

70
Q

International Union for the Conservation of Nature (IUCN):

A
  • Assist in securing agreements between nations
  • IUCN publishes the red list, detailing the current conservation status of threatened animals
  • Countries can then work together to conserve these species
  • Also involved in the establishment of the Convention on International Trade in Endangered species
  • Treaty regulates the international trade of wild plant and animals specimens and their products
  • Require international cooperation to safeguard certain species from over exploitation
  • More than 35,000 species of animals and plants and protected by this treaty

Biology (33 decks)

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