4.2.1 Biodiversity Flashcards
(112 cards)
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