11 - Biodiversity 🪸 Flashcards
What is habitat biodiversity?
the number of different habitats found within an area
What is the habitat biodiversity in the UK?
Large, due to meadows, woodlands, streams and sand dunes
What is the habitat biodiversity in Antartica?
Smaller, as all covered by ice
What is the two components of species biodiversity?
species richness and species evenness
What is species richness?
the number of different species living in an area
What is species evenness?
the comparison of the number of individuals of each species living in a community
What is genetic biodiversity?
the variety of genes that make up a species
What does greater genetic biodiversity result in?
A species better adapted to their environment
Define sampling
taking measurements of a limited number of individual organisms present in an area
What is the number of individuals in a species known as?
the abundance
What can the results of a sample be used for?
To make generalizations, estimates on numbers, characteristics and species distribution
What is random sampling?
Selecting individuals by chance, so each individual in a population has an equal likelihood of selection
How can random sampling be done?
Using a computer to randomly generate coordinates
What are the 3 non-random sampling techniques?
- Opportunistic
- Stratified
- Systematic
What is opportunistic sampling?
The weakest form of sampling because it uses organisms that are conveniently available
What is stratified sampling?
Dividing populations into a number of sub-groups, then randomly selecting individuals from those
What is systematic sampling?
Different areas within an overall habitat are identified, which are then sampled separately
What is a line transect?
Marking a line along the ground between 2 poles, and taking samples at specific points
What is a belt transect?
Two parallel lines are marked, and samples are taken of the area between the 2 lines
What impacts the reliability of sampling?
- sampling bias
- chance
Why is it important to conserve habitats with low biodiversity?
Rare species may not survive elsewhere
What does Simpson’s Index of Diversity measure?
biodiversity, taking it account both species richness and evenness
What does 0 mean in Simpson’s Index of Diversity?
no diversity
What does 1 mean in Simpson’s Index of Diversity?
infinite diversity
How is genetic biodiversity created amongst species?
Alleles
Increasing Genetic Biodiversity
What is gene flow?
When an individual migrates from one population and breeds with a member of another population - interbreeding
Decreasing Genetic Biodiversity
What is selective breeding?
Specific individuals are chosen to breed for their advantageous characteristics
Decreasing Genetic Biodiversity
How does captivity decrease genetic biodiversity?
Where only a small number of individuals of a species are available to breed
Decreasing Genetic Biodiversity
How does natural selection decrease this?
Species with advantageous characteristics live, and less advantageous characteristics are lost
Decreasing Genetic Biodiversity
What are genetic bottlenecks?
Where few individuals within a population survive an event or change
Decreasing Genetic Biodiversity
What is the founder effect?
Where a small number of individuals create a new colony, geographically isolated from the original. The gene pool for this new population is small
Decreasing Genetic Biodiversity
What is genetic drift?
Due to random nature of gene inheritance from parents, the frequency of occurrence of an allele will vary
What are polymorphic genes?
genes that have more than one allele
Are most genes polymorphic or monomorphic?
Monomorphic = a single allele exists for the gene
What is the advantage of monomorphic genes?
The basic structure of individuals within a species remains consistent
Formula for the proportion of polymorphic gene loci
number of polymorphic gene loci / total number of loci
What does the greater proportion of polymorphic gene loci mean?
Greater genetic biodiversity
What 3 bad humans influences are on biodiversity?
- deforestation
- agriculture
- climate change
How does deforestation affect biodiversity?
- reduces number of trees
- reduces species diversity
- reduces habitats
- forces migration
How does agriculture affect biodiversity?
- deforestation to create space
- removal of hedgerows
- use of chemicals
- herbicides used to kill insects
- monoculture
How does climate change affect biodiversity?
- melting of polar caps removes habitat
- rising sea levels
- higher temp and less rainfall changes environment
Reasons for maintaining biodiversity
Why is it maintained for aesthetic reasons?
- enriches our lives
- nature provides inspiration
- reduces stress
Reasons for maintaining biodiversity
Why is it maintained for ecological reasons?
- organisms are interdependent on each other for survival
- keystone species maintain the structure of an ecology community
What are keystone species?
Species that have a disproportionally large effect on their environment relative to their abundance
Reasons for maintaining biodiversity
What economical reasons for maintaining biodiversity are there?
- conserve natural resources
- medicines
- protection against natural disasters
- ecotourism
Reasons for maintaining biodiversity
What are the farming reasons for maintaining biodiversity?
- prevents soil depletion, so crops have good yields
- to prevent soil erosion and desertification affecting yield
Reasons for maintaining biodiversity
What are the farming reasons for maintaining biodiversity?
- prevents soil depletaion, so crops have good yeilds
Define conservation
the preservation and careful management of the environment
What is in situ conservation?
within the natural habitat
What is ex situ conservation?
outside of the natural habitat
What are the categories of conservation statuses?
- extinct
- extinct in the wild
- endangered
- vulnerable
- non-threatened
- least concern
Define sustainable development
economic development meeting today’s needs without impacting the future
Pros of in situ conservation
- maintains genetic biodiversity
- allows evolution so the species can continuously adapt to the environment
- preserves interdependent relationships
- cheaper
In situ
What is necessary for successful wildlife reserves?
active management
In situ
What are some active management techniques in wildlife reserves?
- controlled grazing
- restricting human access
- controlling poaching
- feeding animals
- reintroduction of species
- removing invasive speeches
- halting succession
What is succession?
a natural process in which early colonizing species are replaced over time until a stable mature population is achieved
In situ
What is the only statutory marine reserve in England?
Lundy Island
In situ
Why are marine reserves so important?
to preserve species-rich areas
When is ex situ conservation normally used?
Alongside in situ
Ex situ
How can botanic gardens help to maintain biodiversity?
Plant species can be provided with the best resources to grow
Ex situ
How do seed banks maintain biodiversity?
store seeds so new plants can grow in the future
Ex situ
Why can’t all plant seeds be stored in seed banks?
some seeds die when dried and frozen (most tropical rainforest tree seeds)
Ex situ
What do captive breeding programs do?
Create a stable, healthy population of a species, and then reintroduce them into their natural environment
Ex situ
Why is maintaining genetic diversity in captive breeding programs hard?
All bred together, so inbreeding
Ex situ
Why might some organisms born in captivity not then be suitable for release into the wild?
- disease
- behavior
- genetic races
- habitat
Conservation Agreements
What do the International Union for the Conservation of Nature do?
assist in securing agreements between nations to help conserve animals
Conservation Agreements
What did the IUCN create?
CITES = a treaty regulating the international trade of wild plant and animal specimens and their products
Conservation Agreements
What was the Rio Convention?
In 1992 when 172 nations created the Earth Summit, a meeting resulting in conservation agreements between countries
Conservation Agreements
What is the countryside stewardship scheme?
UK govt offer payments to farmers and other land managers to enhance and conserve the English landscape
Conservation Agreements
What are some specific aims of the countryside stewardship scheme?
- sustain beauty
- improve wildlife habitats
- improve opportunities for countryside enjoyment
- restore neglected land
Sampling techniques
What is a pooter?
used to catch small insects by sucking on a mouthpiece to draw insects into a chamber
Sampling techniques
What can sweep nets catch?
insects
Sampling techniques
What do pitfall traps catch?
catch small crawling invertebrates, like beetles, spiders, slugs
Sampling techniques
How do pitfall traps work?
a hole is dug into the ground which insects fall into. It is covered with a roof-structure so the trap doesn’t fill with rain
Sampling techniques
What is tree beating?
a white cloth is stretched under a living tree/bush. It is then shaken, dislodging animals onto the sheet
Sampling techniques
What is kick sampling?
A river bank and bed is kicked to disrupt the substrate. A net is then held down stream to capture any organisms released
Sampling techniques
What is used to sample plants/slow moving animals?
quadrats
What is a point quadrat?
a frame of a horizontal bar. At set intervals along the bar, long pins can be pushed through the bar to reach the ground. Each species of plant the pin touches is recorded
What is a frame quadrat?
a square frame divided into a grid of equal section
What are the 3 main sample ways of using frame quadrats?
- density
- frequency
- percentage cover
How are frame quadrats used to sample density?
If individual plants can easily be seen, count the number of them in a quadrat to get density per square metre
How are frame quadrats used to sample frequency?
Can use the small squares in a quadrat to count the number of squares a species is present in
How are frame quadrats used to sample percentage cover?
Used for speed as lots of data can be quickly collected. It is useful when species are abundant and hard to count by estimating the area within a quadrat
Why is it hard to estimate animal population size?
They constantly move
What is the capture-mark-release-recapture technique?
Capturing and marking as many organisms as possible. Then releasing them, allowing time for them to redistribute in habitat before recapturing and comparing figures
What does the greater number of marked individuals recaptured mean?
The smaller the population
What are abiotic factors?
non-living conditions in a habitat that have a direct impact on organisms
What are the advantages of being able to quickly measure abiotic factors?
- rapid changes can be detected
- human error is reduced
- high degree of precision
- data can be stored and tracked on a computer
