4.2.1 Biodiversity Flashcards
Define ecosystem
All the interacting living organisms and non-living conditions in an area
Define community
all the populations of living species in a particular habitat at a particular time
Define habitat
An area that a particular species lives in
Define species
The smallest similar group of organisms able to reproduce to give fertile offspring.
Define population
All the individuals of one species living in a specific area at a specific time.
Define biodiversity
the variety of living species in an area
Range of habitats
Define habitat diversity
The number of different habitats in an area
Define genetic diversity
the variety of alleles within a species
Define species diversity
the number of different species found in an area and the abundance of each species
What are the 3 levels of biodiversity?
Habitat
Species
Genetic
What are 3 examples of different habitats?
Desiduous woodland
Fen
Lake
Define biotic factor
the living components in an ecosystem
Give examples of biotic factors
predation
parasites
species
population size
Define abiotic factor
the non-living components in an ecosystem
Give examples of abiotic factors
pH
soil nutrients
climate
rainfall volume
temperature range
light intensity
Define sampling
taking measurements of a limited number of individual organisms or locations within a larger population or area
Why is sampling important?
whole population/ too large to collect data from
samples are quicker + cheaper and can provide good estimates for entire populations
What are the two usual ways to take a sample?
Random sampling
Non- random sampling
What is random sampling?
- selecting individuals/locations to be samples by chance
- ensures each individuals/locations has equal (=) likelihood of being in the sample
What is non-randomly sampling?
- sampling when there is some method to the individuals/locations being sampled
- each individual or location does not have equal likelihood of being in the sample
Describe method of random sampling an area
- place 2 tape measures at 90 degree angle to eachother
- use a random number generator to create coordinates
- place centre of the quadrat at coordinate
- count relevant organisms in the quadrat
- repeat as many times as possible
Name the 3 main techniques of non- random sampling and describe them
- OPPORTUNISTIC - samples chosen by investigator, simple to carry out, biased
- STRATIFIED - population divided into groups and a sample taken from each group proportional to its size
- SYSTEMATIC - samples taken at fixed intervals often along a line (transect) sections of area identified and sampled separately
Define frame quadrat
a square, rigid structure of fixed size used to identify an area to be sampled. usually divided into a grid of equal sections
Define point quadrat
- frame containing horizontal bar
- at set intervals along the bar long pins pushed through bar to reach the ground
- each species of plant the pin touches is recorded
Define line transect
mark out a line along the ground between two poles and record the location and type of each species that touches the line.
Define belt transect
two parallel lines are marked and samples are taken of the area between the two lines
Define interrupted belt transect
sampling using a frame quadrat at specific intervals along a line transect
Method to sample an area using an interrupted belt transect
- mark a line along the ground between 2 poles
- at regular intervals place a frame quadrat against the line
- take a sample
When would random sampling would be appropiate?
- large area of the same type
When would systematic sampling be appropriate?
- to look for change across an area
What are 5 ways to sample animals? Describe them
- POOTER - small insecets - sucked into chamber
- SWEEP NETS - catch insects in long grass
- PITFALL TRAPS- catch small crawling invertebrates -
hole dug in ground deep enough that they cannot crawl out
put in a jar
covered so doesnt fill with rain water
left overnight so nocturnal animals fall in - TREE BEATING - sample animals living in tree/bush
large sheet under tree
tree shaken and animals fall onto sheet - KICK SAMPLING - sample organisms in river
river bed ‘kicked’ to move substrate
net held downstream to collect dislodged creatures
What are 2 ways to sample plants/very slow animals?
quadrats - point or frame
What are 3 ways to colect data using a frame quadrat?
Percentage Cover - estimate the percentage of the quadrat area that is covered by the organism
Density - counting number of individuals to give a number per m^2
Frequency - count the number of small divisions the species is present in - if quadrat divided into 100 small squares and organis present in 65 of them = 65%
Name and state the equipment used to measure 6 abiotic factors
wind speed - anemometer
light intensity - light meter
relative humidity - humidity sensor
pH - pH probe
Temperature - temperature probe
oxygen content in water - dissolved oxygen probe
Explain why a temperature probe linked to a data logger may be advantageous over the use of a thermometer when investigaring factors affecting the abundance of distribution of organisms in an area
-can record rapid changes
- high precision measurements with reduced chance of human error
What are 2 ways to measure species biodiversity?
Species richness
Species evenness
What is species richness?
- the number of different species in an area
- higher the number = greater species richness
What is species evenness?
- the number of individuals of a species in an area
- more similiar population size of each species = greater species evenness
How can the population size of animals be estimated?
capture - mark - release - recapture method
How can the population size of plants be estimated?
Samples taken with quadrats to find average per m^2
–> multiply by total area = population size
How does measuring species diversity lets us get information about the stability of an ecosystem/degree of pollution?
Stable ecosystem = high biodiversity w/ lots of species + even + large population sizes
How is species diversity measured?
Simpson’s Index of diversity
(D)
What two factors does simpsons index of diversity take into account?
Species richness
Species evenness
What do each of the symbols in Simpsons equation mean?
D = 1–Σ [(n/N)2]
Σ = sum of
n = total number of organisms for a single species
N = total number of organisms of all species
What numbers can Simpsons index be between?
0 and 1
What does 0 on simpsons index of diversity show?
0 = no biodiversity
What does 1 on simpsons index of diversity show?
closer to 1= more diverse habitat
What are typical features of a habitat with low biodiversity?
- few successful species
- extreme conditions few ecological niches
- few species w/ specific adaptations
- relatively simple food webs
- change has major effects on ecosystem
What are typical features of a habitat with high biodiversity?
- many successful species
- benign conditions many ecological niches
- many species w/ few specific adaptations
- complex food webs
- change has small effects on ecosystem
Why does a high genetic biodiversity increase species chance of long term survival?
Greater genetic biodiversity = more likely to survive a change in environment + continue reproducing
have advantageous allele - adapted to change
What are 2 ways to increase genetic biodiversity
- interbreeding between populations
- mutations in DNA
How does interbreeding between populations
increase genetic biodiversity?
transfers alleles between populations - gene flow
How does mutations in DNA
increase genetic biodiversity?
mutations in DNA creates more alleles
What are 6 factors that can cause a decrease in genetic diversity?
-selective breeding
-captive breeding
-rare breeds
-artificial cloning
-natural selection
-the founder effect
-genetic drift
-genetic bottlenecks
How does selective breeding decrease genetic biodiversity?
specific alleles are selected, reduces number of possible alleles within a population
How does captive breeding decrease genetic diversity?
there is only a small number of individuals available for breeding
How does artifical cloning decrease genetic diversity?
artifical cloning = asexual reproduction
- no genetic variation/mutations
How does natural selection decrease genetic diversity?
species evolve to contain primarily the alleles which code for advantageous characteristics
Why do captive breeding programmes in zoos have low genetic biodiversity?
there are a small number of individuals so limited number of different alleles
Define polymorphic in terms of genes
genes with different possible alleles
Define locus in terms of genes
the position of a gene on a chromosome
What is the equation to measure genetic diversity?
proportion of polymorphic gene loci =
(number of polymorphic gene loci / total number of loci)
Between which values can proportion of polymorphic gene loci be?
what does each value mean?
0 and 1
or converted to %
0 = no diversity
1= all genes polymorphic
What are the 3 main factors affecting biodiversity that have come about from increased human population?
-Human population growth=
- Increased agriculture
- climate change
- deforestation
Describe th change in human population since 1800
now double that in 1960
7 x size in 1800
Why is the human population increasing so rapidly?
Improvements in:
- medicine
- hygiene
- housing & infrastructure
What are 4 ways on how deforestation affects biodiversity?
- reduce number of trees
- takes out one species leaving the rest
- reduces number of animal species
- animals forced to migrate - increaesd biodiversity in other areas
What are 5 methods in agriculture which affects biodiversity?
- deforestation
- removing hedgerows
- pesticides&herbicides
- removing weeds - plants growing where they are unwanted + compete with crops
- monoculture - (growing of a single variety of single crop)
- animal biodiversity reduced as plant food sources removed
Define global warming
a gradual increase in the overall temperature of the earths atmosphere
Define climate change
a change in global or regional climate patterns, like temperature and rainfall patterns
Why is global warming happening?
greenhouse effect caused by increased levels of CO2, CFCs and other pollutants
Why is climate change happening?
natural but humans speeding it up by:
- increased emissions of greenhouse gases e.g. CO2
What is some evidence for climate change?
- Increasing global average temperatures
- warming trend ~2x of when 100 yrs ago
- global ocean temperatures rising
- more precipitation
- reduced glaciers + ice caps
- arctic temps increasing
- sea levels rising
How are human activities contributing to climate change?
CO2 production
CFCs
What are 4 ways how climate change can affect biodiversity?
- melting polar ice caps = affect organisms living there
- rising sea levels = flood low lying land, salt water further up rivers
- higher temps = less rainfall
- insect lifecycles change = pollination affected
What are 3 reasons to maintain biodiversity?
Aesthetic
Ecological
Economic
Define Ecological in context of reasons for maintaining biodiversity
reasons concerning the potential impact on other species and whole ecosystems
Define Economic in context of reasons for maintaining biodiversity
reasons involving people, communities or companies earning or making more money from the biodiversity in a sustainable way
Define Aesthetic in context of reasons for maintaining biodiversity
reasons based around the beauty of nature and its ability to enrich lives and inspire people
What are 3 aesthetic reasons for maintaining biodiversity?
- enriches lives = relaxation
- inspiration to musicians, writers
- patients recover better when surrounded by nature
What are 8 economic reasons for maintaining biodiversity?
- Soil depletion (bc of continuous monoculture) - more vulnerable to insects = more money on pesticides
- raw materials - industry can collapse without them
- losing species before medicine/chemicals discovered
- soil erosion - reduce ability to grow crops - country dependant on others for resources
- high biodiversity = protects against abiotic factors and disease
- attractive areas = tourists = money
- potential manufacture of new product in future
- plant varieties needed for cross breeding to introduce new favourable characteristics
What are 8 economic reasons for maintaining biodiversity?
- Soil depletion (bc of continuous monoculture) - more vulnerable to insects = more money on pesticides
- raw materials - industry can collapse without them
- losing species before medicine/chemicals discovered
- soil erosion - reduce ability to grow crops - country dependant on others for resources
- high biodiversity = protects against abiotic factors and disease
- attractive areas = tourists = money
- potential manufacture of new product in future
- plant varieties needed for cross breeding to introduce new favourable characteristics
What are 2 ecological reasons for maintaining biodiversity ?
- to protect keystone species
- to maintain genetic resources (e.g. materials from plants,
animals, microorganisms)
food+drink, clothing (cotton), drugs, fuels, industrial - all organisms interdependant on others for survival
loss of one species can have drastic effects on
ecosystem e.g. food chain, disruption of nutrient cycles
Define keystone species
species essential for maintaining biodiversity, they have a large effect on their environment relative to their abundance
Why are keystone species important in maintaining biodiversity?
they affect many other organisms in the environment.
their removal would drastically effect species richness and evenness
Give example of keystone species and how it effected the ecosystem?
(WOLF)
- Wolf - keystone species in America
- Eliminated in 20th century.
- No wolves to hunt elk, elk population increased= overgrazing
- overgrazing = loss of plant species
- loss of species depending on those plants e.g. beavers + songbirds
Define conservation
the maintenance of biodiversity
Define In situ conservation
protecting a species within their natural habitat
“on site”
Define Ex situ conservation
protecting a species out of their natural habitat
“off site”
Name 2 methods of in situ conservation
Wildlife reserves
Marine conservation zones
What are 7 methods of active management in wildlife reserves? (in situ)
- Controlled grazing
- Regulated human access
- Controlling poaching
- Feeding animals - help reach reproductive stage
- Reintroduction of species
- Culling or removing invasive species
- Halting succession
How do marine conservation zones help maintain biodiversity?
(in situ)
- Ensure sustainable fishing
- Provide areas where populations can grow/recover
Name 3 methods of ex situ conservation
- Botanical gardens
- Seed bands
- Captive breeding programmes
How do botanical gardens help maintain biodiversity?
Plant species grown successfully with optimum conditions
= no extinction
How do seed banks help maintain biodiversity?
Store seeds so species can be grown = preventing extiction
Describe 3 ways zoos contribute to conservation
- Captive breeding programmes - aim to build up healthy populations of species + Reintroduce them into wild
- Carry out research to support conservation efforts elsewhere
- Animals given food, water, shelter, absence od predators, vet care
Explain how seed banks store the seeds?
- dried
- stored at -20°C
Why do seed banks store seeds in those condition?
to maintain viable
- slows down loss of ability to germinate
How do captive breeding programmes help maintain biodiversity?
aim to build up healthy populations of a species + reintroduce into wild - prevent extinction
How do captive breeding programmes maintain/increase genetic diversity?
- global catalogue kept of gentic information of individuals = most suitable matches can be made to maintain genetic diversity
- artificial insemination + embryological techniques used to prevent animals having to be transported across the world
Why is it not possible to release some captively bred organisms back into the wild?
- diesease - captive populatins may not hav developed resistance to wild diseases
- lack of learnt behaviour to survive
- genetic races - captive population may be too genetically different to wild pop to interbreed
- insufficient wild habitat remaining to support new individuals- habitat has to be replaced / or stress + competition will mean individuals fight for small number of resources
State the full name of the IUCN
International Union for the Conservation of Nature
What is the role of the IUCN?
- involved in agreements between nations
- publish red list each year of endangered species
- involved in setting up CITES to regulate trade of endangered species across borders
Name 2 international conventions that aim to protect biodiversity
- The Rio Convention
- Convention on international trade in endangered species
(CITES)
State the full name of the CITES
Convention on international trade in endangered species
How does CITES help protect biodiversity?
Regulates trade in wild plants and animals across borders to prevent over-exploitation of certain species
What were the 3 outcomes from the Rio convention 1992
leading to…
- The convention on biological diversity
- The united nations framework convention on climate change
- The united nations convention to combat desertification
State the full name of the CBD
Convention on biological diversity
How does the CBD help protect biodiversity?
National strategies for sustainable development
Name a local scheme in England that aimed to protect biodiversity
Countryside Stewardship Scheme
How did the Countryside Stewardship Scheme aim to protect biodiversity
- offered governmental payments to farmers + land owners for:
- sustaining beauty + diversity of landscape
- improving, extending + creating wildlife habitats
- restoring neglected land + conserving historical +
archaeological features - improving opportunities for countryside employment
Why is sampling important
whole population/ too large to collect data from
samples are quicker + cheaper and can provide good estimates for entire populations
