How do you interpret a rank abundance curve?
How do you interpret a rank abundance curve?
Interpreting a rank abundance curve A steep gradient indicates low evenness as the high-ranking species have much higher abundances than the low-ranking species. A shallow gradient indicates high evenness as the abundances of different species are similar.
What is the broken stick model?
The Broken Stick distribution is a standard null. model of community structure. It predicts the distribution of. species’ relative abundances (i.e. dominance/diversity relations) when resources are partitioned into niches at random.
Which rank abundance model has the least equitable distribution of species?
dominance-preemption model
The dominance-preemption model, which produces the least equitable species distribution, has successive species preempting a dominant portion (50% or more) of the remaining niche space; the first, most dominant species takes more than 50% of the total niche space, the next more than 50% of what remains, and so on.
What is Shannon Wiener diversity?
The Shannon-Weiner diversity represent the proportion of species abundance in the population. Its being at maximum when all species occur in similar number of individuals and the lowest when the sample contain one species.
What is a critical factor affecting a community’s composition after a major disturbance?
Community structure is influenced by many factors, including abiotic factors, species interactions, level of disturbance, and chance events. Some species, such as foundation species and keystone species, play particularly important roles in determining their communities’ structure.
What is niche preemption?
of niche preemption by which a sequential colonization of. species into a community is assumed. The first species that. colonizes the community preempts the first k fraction of the. total resource or space.
How do you make a rarefaction curve?
The rarefaction curve is a plot of the number of species against the number of samples. This curve is created by randomly re-sampling the pool of N samples several times and then plotting the average number of species found on each sample.
How do you use the Shannon diversity index?
Take the natural logarithm of each proportion (lnp) and then multiply the proportion and the ln of the proportion (p*lnp). Add these values together, take the negative value of it (to make it positive) and you will have your Shannon Weiner index score (H’).
What is a rarefaction curve?
Rarefaction curves are plots of the number of individuals on the x-axis against the number of species on the y-axis. Sample sizes (N) may differ, but the relevant sections of the curves can still be visually compared.
What does Simpson’s Diversity Index tell you?
Simpson’s Diversity Index is a measure of diversity which takes into account the number of species present, as well as the relative abundance of each species. As species richness and evenness increase, so diversity increases. With this index, 1 represents infinite diversity and 0, no diversity.
