Db is the particular measure of species richness and it decreases when s (the number of different species) decreases. Db decreases when N (the number of individuals) increases.
2. How s and N affect the Simpson Index?
Simpson Index is a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. In this case, a few rare species (s) with only a few representatives (N) will not affect the diversity.
3. Are the high and low values obtained from this data set for the Menhinick, Simpson and Shannon indices the highest possible for these indices? If not, can you determine the range?
The high and low values obtained from our data set for the Menhinick, Simpson and Shannon are …show more content…
not the highest possible for these indices. By changing the values of the variable mean that we can change the value of the indices. Therefore, we cannot determine a specific range.
4. What effect does adding additional rare species to a community have on Ds?
Ds is the Simpson Index which measures the likelihood that any two species will be present in a randomly sampled pair of individuals.
A community dominated by one or two species is considered to be less diverse than one in which several different species have a similar abundance. Adding additional rare species in a community increases the Ds’s measure of diversity and complexity which takes into account the number of species present as well as the relative abundance of each species.
5. What effect does sample size have on H’?
Sample size does not do anything if the diversity is the same. However, if we take a sample size from a very diverse community, the uncertainty as to the content of that sample increases because H’ (Shannon Diversity) measures species richness.
6. How does your J’ value for Community A compare with your J’ value for Community D? Do you agree with the implications of this outcome?
Based on our data, J’ value for Community A with J’ value for Community D is the same because it is only 1. I agree with the implications of this outcome because both communities had the same constant number of species and the evenness which is the proportional abundance of species is the
same.
7. Rank the five communities as most likely to least likely to occur in nature based on the data at hand. (Use your common sense and intuition here and explain your reasoning.)
Community A & D: Most Likely (Both communities have their own constant number of species and number of individuals. It displays a tough and even outcompeting situation which is very common in nature)
Community B: Second Most Likely (Most diversity to be in nature because there are different numbers for each species)
Community E: Third Most Likely (Only 5 species in the community with the same number of individuals and this is rare to see because it is even)
Community C: Least Likely (Only 91 individuals for 1 species while the rest is the same number of individuals for each species. This is rare to occur in nature)