Biodiversity-4.2 Flashcards
Define biodiversity
A measure of the variation found in the living world
Define a species
A group of individual organisms that are very similar in appearance ,anatomy, physiology,biochemistry and genetics. Whose members are able to reproduce freely to produce fertile offspring.
What is a habitat?
A place where an organism lives
What is habitat biodiversity?
-the range of habitats in which different species live
-e.g. sand dunes, woodland,meadows,streams
What contributes to species biodiversity?
Species richness and species evenness
What is genetic biodiversity?
-different breeds within a species
How can random sampling be carried out?
-sample sites are randomly selected
-e.g.
.using randomly generated numbers as coordinates for your samples
What is the advantage of random sampling?
-ensures that the data is not biased by selective sampling
What are the disadvantages of random sampling?
-may not cover all areas of habitat equally
-species with a low presence may be missed, leading to an underestimate of biodiversity
What are three examples of non-random sampling?
-opportunistic
-stratified
-systematic
How is opportunistic sampling carried out?
-when the researcher makes sampling decisions based on prior knowledge or during the process of collecting data
-the researcher may deliberately sample an area that they know or can see contains a particular species
What are the advantages of opportunistic sampling?
-easier and quicker than random sampling
What are the disadvantages of opportunistic sampling?
-the data may be biased
-can lead to an overestimate of biodiversity or an overestimate of a particular species (e.g. if it is very colourful?
How is stratified sampling carried out ?
-dividing a habitat into areas that appear different and sampling each area separately
What are the advantages of stratified sampling?
-ensures that all different areas of habitat are sampled and species are not underrepresented due to the possibility that random sampling misses certain areas
What are the disadvantages of stratified sampling?
-may lead to the over-representation of some areas in the sample
-e.g. a disproportionate number of samples are taken in small areas that look different
How is systematic sampling carried out?
-when samples are taken at fixed intervals across the habitat
-e.g. line transects and belt transects
What is an advantage of systematic sampling?
-very useful when the habitat shows a clear gradient in some environmental factors
-such as getting drier further from a pond
What is a disadvantage of systematic sampling?
-only the species on the line or within the belt can be recorded
-other species may be missed, leading to an underestimate of biodiversity
What is species evenness?
- a measure of how evenly represented the species are
-to measure this you need to carry out a quantitative survey
What is species richness?
-a measure of how many different species are present
-to measure you need to count all the species present in a habitat
How can you interpret the value of Simpson’s index?
-a high value indicates a diverse habitat-the habitat tends to be more stable and able to withstand change
-a low value indicates a habitat dominated by a few species- a small change to the environment (e.g. a disease, a new predator) that affects one of those species species could damage or destroy the whole habitat.
What is a quadrat?
-square frame that is used to define the size of the sample area often 50cm or 1m on each side
-they are suitable for sampling plants or slow moving animals
-quadrats can be places in a habitat randomly or a long a transect
Measurements within a quadrat might include…
-the number of species present
-number of individuals of a species present , i.e. species abundance
-the presence/absence of a species
-the percentage cover of a species (you can use a point frame to help with this )
What is a point frame?
-you can measure percentage cover using a point frame
-it is a frame holding a number of long needles/pointers
-you lower the frame into the quadrat and record any plant touching the needles
-if frame has 10 needles and you use it 10 times then you will have 100 readings so each plant touching the needle will have 1% cover (it is possible to find you have a high percentage cover in some habitats)
-do not forget to record bare ground
-it may be best to use a point frame at regular intervals across the quadrat
What is a transect?
- a line along which samples can be taken
-they are used during systematic sampling to assess how abundance and distribution of organisms is affected by changes in abiotic factors across a habitat
-transect lines are laid out across a habitat along the gradient that is to be investigated
How do you do a line transect?
-lay out a measuring tape in a straight line across the sample area
-at regular distances along the tape e.g. every 1metre, record the identity of the organisms that touch the line
How do you do a belt transect?
-lay out a measuring tape in a straight line across the sample area
-place quadrats at regular intervals (interrupted belt transect)
-or continuously (continuous belt transect) along the tape
-record the abundance or percentage cover of each species within each quadrat
What are sweep nets?
-strong nets made from a material with very small holes
-the nets can be swept across vegetation e.g. grass or tree branches to catch flying insects and insects that live on leaves
-after sampling the insects in the net can be counted and identified e.g. empty the contents onto a white sheet to identify them taking care that the insects do not crawl or fly away - you can use a pooter to collect insects before they fly away
What is a pitfall trap?
-a trap set in the soil to catch small animals
-they are small containers that are buried in the soil so that the rim is just below the surface
-ground-dwelling invertebrates fall into the trap as they walk along the ground and then cannot climb out again
-the trap should contain a little water or scrunched up paper to stop animals crawling out again, also some leaf litter or newspaper can be used to allow smaller insects to hide from larger predatory insects
-the trap should be sheltered from the rain so it does not fill up e.g a canopy
What is a pooter ?
-small plastic or glass containers with two tubes extending from the lid
-the tubes can be used to suck up small invertebrates
-the first tube is placed over the insect and the second tube is used to create suction
-once inside the container the sampled organisms can be easily viewed and identified
What is the equation for the mark-release-capture method?
N = (n1 × n2) ÷ m2
-N=population estimate
-n1=number of marked individuals released
-n2=number of individuals in the second sample (marked and unmarked)
-m2=number of marked individuals in the second sample
What do the symbols stand for in the Simpson’s diversity index equation?
-D= Simpson’s diversity index
-N= total number of organisms of all species/ total percentage cover for plants
-n=number of organisms of a particular species/ percentage cover for plants
What is the equation for polymorphic gene loci?
Proportion of polymorphic gene loci =
Number of polymorphic gene loci
————————————————————
Total number of loci
What is a locus in relation to genetics?
-the position of that gene on a chromosome
What is a polymorphic gene locus?
-a locus that has more than 2 alleles
How do you calculate genetic diversity?
How does human population growth affect biodiversity?
-increases the demand for resources from the environment
How does agriculture affect biodiversity?
-reduces biodiversity by monoculture ( a crop consisting of one strain of one species)
-use of herbicides and pesticides
-deforestation to clear land for crops
How is climate change a factor that affects biodiversity ?
-climate change means significant, long-lasting changes in weather patterns
-it is causing animals to migrate or to die
What are the 2 ecological reasons for maintaining biodiversity?
-protecting keystone species- species that have a larger impact on the ecosystem than others, when these species are lost there are several knock-on effects. E.g elephants -the way they graze helps to maintain ecosystem, elephant dung provides a habitat for many important fungi and insect species. When elephant population decreases there is a negative impact on the savannah
-maintaining genetic resources
What is the economic reason for biodiversity?
-reducing soil depletion (the loss of soil fertility caused by the removal of minerals through continuously growing monoculture plants)
What is the aesthetic reason for biodiversity?
-protecting landscapes
What is conservation in situ ?
-carrying out active management to maintain the biodiversity in the natural environment
-e.g. marine conservation zones and wildlife reserves
What are marine conservation zones?
-areas of the sea set aside to conserve the diversity of species and habitats
What are wildlife reserves?
-areas set aside for the conservation of species or habitats
What are the advantages and disadvantages of in situ conservation ?
ADVANTAGES
-plants and animals are conserved in their natural environment
-allows management of these areas to ensure that ecological integrity is maintained
-facilitates scientific research
DISADVANTAGES
-endangered habitats may be fragmented and each small area may not be large enough to ensure survival
-population may have already lost much of its genetic diversity
-the conditions that caused the habitat or species to become endangered may still be present
What is conservation ex situ?
-conservation outside the normal habitat of the species
E.g- seed banks, botanic gardens and zoos
What are the advantages and disadvantages of ex situ conservation?
ADVANTAGES
-organisms protected from predators and poaching
-health of individuals can be monitored and medical assistance given as required
-genetic diversity of the population can be measured
-animals can be bred to increase the numbers of an endangered species
-selective breeding can be carried out to increase genetic diversity
DISADVANTAGES
-the organisms are living outside their natural habitat
-a captive population is always likely to have a limited genetic diversity
-the correct conditions for survival may be difficult to achieve
-even if reproduction is successful the animals have to survive reintroduction into the wild where they need to find food and survive predators
-when reintroduced there can be difficulties with acceptance by the existing wild members of the species
What was the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) and what are its aims?
-an international agreement between the majority of governments in the world
-first agreed in 1973
-overall aim is to ensure that international trade in specimens of wildlife does not endanger their survival.
It aims to:
.regulate and monitor international trade in selected species of plants and animals
.ensure that international trade does not endanger the survival of populations in the wild
.ensure that trade in wild plants for commercial purposes is prohibited
.ensure that trade in artificially propagated plants is allowed, subject to permit
.ensure that some slightly less endangered wild species may be traded subject to a permit, as agreed between the exporting and importing countries
What are the concerns surrounding CITES ?
When the trade of a certain endangered species becomes illegal, its price increases
The increased economic value of the species can be a major incentive for people to break the law
What was the Rio Convention on Biological Diversity (CBD) ?
-The Convention on Biological Diversity (CBD) was signed at the Earth Summit in Rio de Janeiro in Brazil in 1992
-The convention had three main goals:
.The conservation of biological diversity by use of a variety of different conservation methods
.The sustainable use of biological resources
.The fair and equitable sharing of benefits arising from genetic resources
The countries that signed the convention agreed to design and implement national strategies for the conservation and sustainable use of biodiversity, as well as to organise international cooperation and further international meetings
What was the Countryside Stewarship Scheme?
-introduces in England in 1991 applied to land that was not considered to be in an environmentally sensitive area. Payments were made to farmers to enhance and conserve English landscape
-aims were to
-> improve the natural beauty and diversity of the countryside
-> enhance , restore and re-create targeted landscapes, their wildlife habitats and historical features
->improve opportunities for public access
What was the Countryside Stewardhip Scheme replaced by and what are the aims of this other scheme ?
This scheme was replaced by the Environmental Stewardship Scheme (ESS) in 2005
In order to qualify for the scheme, farmers and private landowners have to:
-Provide and protect valuable wildlife habitats such as ponds, hedgerows and buffer zones surrounding farmed areas
-Ensure their land is managed well, maintaining its traditional character
-Protect any natural resources or historic features present on their land
-Conserve any traditional crops or livestock present on their land
-Provide visitor opportunities so people can learn about the countryside and how important it is in sustaining biodiversity
Captive breeding programmes with D.sumatrensis have been unsuccessful
Suggest one other way in which zoos can contribute to the conservation of the Sumatran rhinoceros
(1 mark)
-education/ awareness
(Support for/promote conservation projects/research)
