Research methods- quantitive and numerical measures Flashcards
What is local abundance?
relative representation of a species in a particular ecosystem
How is relative abundance calculated?
dividing the number of species from one group by the total number of species from all groups
What can be used to study an area quickly?
DAFOR scale
Limitation of the DAFOR scale?
not accurate as based on opinions
results not usually suitable for quantative analysis as not numerical
What does DAFOR stand for?
Dominant
Abundant
Frequent
Occasional
Rare
What can be used to get more accurate results for plants?
Quadrat study
What estimate method can be used for animal numbers?
Capture/ Recapture
What is species richness?
number of species within a community or area
what is the limitation of species richness?
does not take into account the distribution of species within the area or what is referred to as species evenness
What is an example of species richness?
2 areas A and B
A 10 species
B 20 species
B has higher species richness
why is species richness more useful then DAFOR?
can be standardised
How do you standardise species richness?
simply decide on a specific area in size to compare two locations
focus on a specific aspect or taxon ( not everything)
What are somethings you may focus on for species richness?
trees
birds
insects
amphibians
What is frequency? (Quadrat)
number of times a plant species occurs in a given number of quadrats
usually a %
How do quadrats show distribution?
Proportion of plots that contain a specific plant can indicate the extent of distribution across the landscape
What is an example of quadrats being used to measure extent?
450 quadrats in shrubland
found desert marigold in 54
frequency = 12% (450/54)
what is species density?
simply the number of species in a specific area
what is the unit for species density?
species/m*2
what is Cover?
the area of the ground surface covered by vegetation or other coverage like litter or moss
how is Cover expressed?
as a %
How do you calculate the Lincoln index?
population size=(number of species in first capture x number of species in second capture)/ number of marked species in second capture
what is the practicality of the Lincoln index?
way to measure population sizes of individual animal species.
What does the Simpsons biodiversity index take into account?
number of species present as well as abundance of each species
what is the formula for the Simpsons biodiversity index?
D= sum of n(n-1)/ N(N-1)
