C11 - Biodiversity Flashcards
What is biodiversity?
Variety of living organisms in an area
Why is biodiversity important?
All species are interconnected so rely on each other
What assessment is taken before a major project is undertaken?
Environmental impact assessment
What levels can biodiversity be studied at?
Habitat diversity
Species diversity
Genetic diversity
What’s habitat biodiversity?
The number of different habitats found within an area
How are habitat and species biodiversity relation?
If habitat biodiversity is greater, species diversity will also be greater
What two factors does species biodiversity?
-Species richness: number of different species living in a particular area
-Species evenness: comparison of the numbers of individuals of each species living in a community
What is genetic biodiversity?
Variety of genes that make up a species of
What is sampling?
Taking measurements of a limited number of imdicyual organisms parent in an area
What can sampling be used to estimate?
-Abundance (number of organisms in an area)
-Characteristic if an organism
Two sampling methods?
Random
Non-random
What is random sampling?
Each individual in the population has an equal likelihood of selection
What is non-random sampling?
Sample is not chosen at random
How could you take a random sample at a grass verge?
1) Mark out a grid on the grass using two tape measures laid at right angles
2) Use random numbers to determine the x coordinate and the y coordinate on your grid
3) Take a sample at each of the coordinate pairs generated
Examples of non-random samples
Opportunistic
Stratified
Systematic
What is opportunistic sampling?
-Weakest
-May not be representative of population
-Uses organisms that are conveniently available
What is stratified sampling?
-Population divided into strata based on a characteristic
-Random sample taken from each sample proportional to its size
What is systematic sampling?
-Areas within an overall habitat are identified, which are then sampled separately
-Uses a line transect or a belt transect
What’s a line transect?
Marking a line along the ground between two poles
Taking sample at specified points
What’s a belt transect?
Two parallel lines marked and samples taken in the area between the lines
Why is a sample not completely reliable?
-Sampling bias: selection process might be biased (accidentally/ deliberately)
-Chance: organism selected may not be representative of the whole population (reduced by larger sample size)
How can you sample animals?
-Pooter: small insects
-Sweep nets: insects un area of long grass
-Pitfall traps: small crawling invertebrates
-Tree beating: invertebrates lining in a tree/bush
-Kick sampling: organisms living in a river
How do you sample plants?
Using a quadrat
What are the two types of quadrat
-Point quadrat: frame containing a horizontal bar, pin placed through hole in bar and species in contact with pin are recorded
-Frame quadrat: square frame divided into grid of equal sections, type and number of species within each section is recorded
How do you collect a valid representative sample of an area?
Use random sampling technique
How do you use a frame quadrat?
-Density: count the number in a 1m by 1m quadrat, gives you density per square metre (absolute measure)
-Frequency: using small grids within quadrat, count number of squares species is present in, convert to percentage (estimate)
-Percentage cover: estimate by eye of the area within a quadrat that a species covered
Take samples at a number of diffeeent points
More samples more reliable
Calculate mean
How can you estimate population size
Capture-mark-release-recapture
How does capture-mark-release-recapture work?
Capture as many individuals of a species in an area
Mark the organisms
Release them
Wait for sometime
Again, capture as many individuals of a species in the same area
By comparing number of marked and unmarked individuals in second sample, scientists estimate population size
What are abiotic factors
Non living conditions in a habitat
How can you mean abiotic factors
Wind speed: anemometer (m/s)
Light intensity: light meter (lux)
Relative humidity: humidity sensor (mg/dm^3)
pH: pH probe (pH)
Temperature: temperature probe (°C)
Oxygen content in water: dissolved oxygen probe (mg/dm^3)
What are the advantages of quick and accurate measurements of abiotic factors using sensors?
Rapid changes can be detected
Human error in taking a reading is reduced
High degree of precision
Data can be stored and tracked on a computer
How can you calculate biodiversity?
Simpson’s Index of Diversity (D)
Formula for simpsons index of diversity
D = 1 - total (n/N)^2
N-total number of organisms of all species
n-total number of organisms of a particular species
What do results of simpsons index of diversity tell you
Value between 0 and 1
0 - no diversity
1 - infinite diversity
What does a low biodiversity value tell us
-Relatively few successful species
-Stressful/extreme environment with few ecological niches
-Relatively few species live in habitat
-Very specific adaptations to environment
-Change in environment would have a major effect on the ecosystem
What does a high biodiversity value mean
-Large number of successful species
-Relatively benign/not stressful environment with more ecological niches
-Many species live in habitat
-Few specific adaptations to environment
-Change in environment would have a relatively small effect on the ecosystem
Why is genetic biodiversity important?
More genetic diversity
More likely to be organisms that carry an advantageous allele
More likely able to adapt to changes in the environment
Less likely to become extinct
What factors increase genetic biodiversity?
-Mutations in DNA: creating new allele
-Gene flow: interbreeding between two populations
-
What factors decrease genetic biodiversity?
-Selective breeding
-Captive breeding
-Rare breeds
-Artificial cloning
-Natural selection
-Genetic bottlenecks (few individuals survive a change/event)
-Founder effect (small number of individuals create a new geographically isolated colony)
-Genetic drift
How do you measure genetic biodiversity
By measuring polymorphism
What is special about polymorphic genes?
Have more than one allele
What are genes that do not have multiple alleles called?
Monomorphic
What’s the formula for the proportion of polymorphic genes.
Proportion of polymorphic gene loci = number of polymorphic gene loci / total number of gene loci
What is loci?
Position of gene on a chromosome
What does a greater proportion of polymorphic gene loci mean?
Greater genetic biodiversity
What are human influences on biodiversity?
-Deforestation: permanent removal of large areas of forest to provide wood for building and fuel
-Agriculture: increasing amount of land has to be farmed in order to feed growing population, requiring land to be cleared for monoculture
-Climate change: release of fossil fuels increasing global temperatures
How does deforestation affect biodiversity?
-Reduces trees present in an area
-Species diversity reduced if a specific species is felled
-Reduces number of animal species present as i destroys their habitat
-Animals forced to migrate increasing biodiversity of other areas
How does agriculture reduce biodiversity?
-Deforestation
-Removal of hedgerows
-Use of chemicals (pesticides)
-Use of herbicides to kill weeds
-Monoculture
Important facts about climate change
-Global temperature rise has almost doubled in past 100 years
-Average amount of water vapour in atmosphere has increased since 1980s
-Global ocean temperatures have increased since 1961
-Global SLR by 1.8m/year from 1961-2003
-Mountain glaciers and snow cover have declined
-Long-term upward trend in precipitation has been observed from 1900s to 2005
How can global warming affect biodiversity?
-Melting of polar ice caps could cause several species to go extinct
-SLR could cause low lying land to flood
-Higher temperatures and lower rainfall could cause several species to go extinct
-Insect life cycles and populations could change, affecting plant pollination
What are reasons for maintaining biodiversity?
Aesthetic reasons
Economic reasons
Ecological reasons
What are aesthetic reasons behind maintaining biodiversity?
-Presence of different species enriches our lives
-Provides inspiration to artists
-Patients recover more rapidly when supported by natural environment
What are economic reasons behind maintaining biodiversity?
-Deforestation can cause soil erosion and desertification reducing ability to grow crops
-Important to conserve all organisms used to make things
-Large scale habitat and biodiversity losses mean species with potential economic importance may become extinct
-Continuous monoculture results in soil depletion
-High biodiversity provides protection against abiotic stresses
-Areas rich in biodiversity attract tourism
-More diversity in ecosystem means more potential products can be manufactured
-Plant varieties are needed for cross breeding
What are ecological reasons behind maintaining biodiversity?
-All organisms are interdependent on others
-Some species play a key role in maintaining the structure of a community (key stone species)
What is conservation?
Preservation and careful management of of the environment and natural resources
What are the two types of conservation?
In situ - within natural habitat
Ex situ - out of natural habitat
How are species classified
Extinct - no organisms of species exist anywhere
Extinct in the wild - no organisms of the species exist in the wild
Endangered - species in danger of extinction
Vulnerable - species considered likely to become endangered in near future
What is sustainable development?
Economic development that meets the needs of people today without limiting the ability of future generations to meet their needs
What does in situ conservation maintain?
Genetic diversity of species and evolutionary adaptation
What active management occurs in a wildlife reserve?
-Controlled grazing
-Restricting human access
-Controlling poaching
-Feeding animals
-Reintroduction of species
-Removal of invasive species
-Halting succession (early colonising species replaced over time)
Key details about marine conservation zones
Less well established that terrestrial ones
Protection against non-sustainable fishing methods
Creates areas of refuge for species populations to grow
Examples of in situ conservation
Wildlife reserves
Marine conservation zones
Examples of ex situ conservation
Botanic gardens
Seed banks
Captive breeding programs
What are botanic gardens
Active management of plant species to provide them with the best resources and conditions to grow
What are seed banks
Gene bank where seeds stored so new plants can be grown in the future
Dried and stored at -20C to maintain their viability
What are captive breeding programmes
Produce offspring in a human controlled environment
Aim to create a stable, healthy population and then reintroduce it into its natural habitat
What affect does captive breeding have on genetic diversity
Reduces it
Why may some organisms born in captivity not be suitable or the wild?
-Loss of resistance of diseases
-Behavioural differences
-Difference in genetics affecting fertility
-Insufficient habitat
What is the role of the International Union for the Conservation of Nature in conservation agreements?
-Assist in securing agreements between nations
-Publish Red List detailing current conservation status of threatened animals
-Established Convention of International Trade in Endangered Species
What is the Rio Convention?
Meeting of nations resulting in these agreements:
-Convention of Biological Diversity (sustainable development)
-United Nations Framework Convention on Climate Change (stabilise ghg conc in atm)
-United Nations Convention to Combat Desertification (reduce effects of drought)
What is the country stewardship scheme?
Local scheme in England that offered governmental payments to farmers and land managers to enhance and conserve the English landscape
Replaced by Environmental Stewardship Scheme
