Flashcards in Quantifying And Measuring Biodiversity Deck (15)
What does vegetation affect?
Temperature, humidity, light and wind speed
What controls biodiversity?
In the environment it’s the physical structure and the nutrition/resources that affects and controls biodiversity
What does the plant dominance index measure and who invented it?
Gives a measure of the competitive ability of plant species and tells you if it will take over an environment
Give some examples of dominant plant species
Nettle (Urtica dioca)
Bracken (Pteridium aquilinium)
Rose bay willow herb
What 4 aspects are taken into account when calculating the dominance index?
1. Growth rate
2. Potential height
3. Potential for lateral spread
4. Litter production
How do you calculate the dominance index?
Species are given a score of 1-5 on each character
The score is summed and divided by 2 to give a score out of 10
Give an example of controlling plant dominance
Rhinanthus minor (Hay rattle)
Prevents grasses in meadows becoming too dominant, allowing other plant species to grow
What is the diversity index?
Measure of the number of species/families/genera and number of individuals of each
Evenness= dominance of species
On the k-dominance curve what do you plot and where?
Different species: x axis
Abundance of each species: y axis
What does Shannon diversity calculate?
The proportion of all individuals that belong to each species
Where do natural communities usually fall on the Shannon diversity?
What does Simpson dominance index measure?
The degree of dominance by a few species in the sample
What does island biogeography take into account?
Rates of migration and dispersal
Controls on species richness
Relationship between the number of species, the size of the island and the distance from neighbours
What is colonisation and extinction dependent on?
The emergence of new ecosystems
Linkage between plants and animals