Biodiversity Flashcards
What is biodiversity?
The variability within species, between species and between ecosystems, variety of organisms present in an area, exists at many levels from local to global, covers all habitats
Why is biodiversity important?
All species are interconnected, depend on others for nutrients, oxygen, shelter
Reduced biodiversity, reduces connections, may harm species in ecosystem
Greater biodiversity = more stable ecosystem
What is an Environmental Impact Assessment (EIA), and why is it necessary?
Measuring biodiversity is integral part of conservation
EIA carried out before any project started, gives info about the species present, assesses the positive and negative effects of the project on the biodiversity of the area
What is a habitat?
A place where individuals in species live
What is the biosphere?
The biosphere is made up of the parts of Earth where life exists—all ecosystems
What is a biome?
A region of the world characterised by its resident life, environment, and climate.
What is an ecosystem?
The interaction between organisms living
together in a particular environment.
What is habitat biodiversity?
Range of habitats in which different species live
Common examples in UK are sand dunes, woodland, meadows, streams, can contain variety of habitats
Each habitat occupied by range of organisms
What is species biodiversity?
Species richness: number of different species living in particular area
Species evenness: comparison of the number of individuals of each species living in a community
Area can differ in species biodiversity even if has same number of species
What is genetic biodiversity?
Variation between individuals belonging to same species, can create breeds within species
High genetic diversity allows species to adapt to environmental changes and inbreeding
How is genetic biodiversity measured?
Species richness: measure of the number of species.
Species abundance: relative measure of the abundance of species.
Species density: an evaluation of the total number of species per unit area
What is sampling?
Taking measurements of specific numbers of organisms
Why is sampling needed?
EIA, disease effect, indicator of climate change/habitat change, want to know what is there, how many are there
Can’t count all individuals, allows us to estimate number of individuals, can also give information on distribution of organisms, spread or clustered for example
What is random sampling?
Selecting by chance
What is opportunistic sampling?
Sampling where a sample is taken when a source is encountered therefore it is based on ease of access
What is stratified sampling?
Random sample taken from each strata, proportional to the size of the population
What is systematic sampling (line and belt)?
Line - samples taken at fixed intervals across a habitat, sample individuals touching line
Belt - samples taken at fixed intervals across a habitat, belt provides more information than line as sampling it at intervals between two parallel lines
What are the advantages and disadvantages of random sampling?
Ensures data is not biased, can cover large areas
May not cover all areas equally, species with low presence may be missed leading to underestimation
What are the advantages and disadvantages of opportunistic sampling?
Easier and quicker than random
Data may be biased, presence of large, colourful species may entice researcher to include that species, may lead to overestimation of importance and biodiversity
What are the advantages and disadvantages of stratified sampling?
Ensured all different areas of habitat are sampled and species are not underrepresented due to the possibility that random sampling misses certain areas
Possibility of over representation of some areas, ie a disproportional number of samples are taken in small areas that look different
What are the advantages and disadvantages of systematic sampling?
Good for environmental gradients (eg rocky shorlines)
Only species on the line or within the belt can be recorded, other species may be missed leading to underestimation
What is sampling bias?
Deliberately or accidentally choosing a sample area. Reduced by random sampling where human involvement is removed
What is the problem with chance when sampling?
Organisms selected may be by chance, not representative of population. Can never be removed, but reduced by large sample size
