Dear Guma, Hope all is well. Charles, My issue is my H’ value is 7,054 and my H’max 4,392 for 21 species so it’s impossible. How do I include this point on a bar graph?

Since some categories from the population may not be present in a sample (especially in a small sample), the sample value of J’ tends to overestimate the corresponding population relative diversity index J′ (which again means that it is a biased estimate). This number represents three standard deviations less than the average.C3: =C2+\$B\$4 To create a sample bell curve, follow these steps: Enter the following column headings in a new worksheet: A1:Original B1:Average C1:Bin D1:Random E1:Histogram G1:Histogram. I guess I am doing similar thing as you do. The ‘Khasi hill sal’ forest ecosystem in Meghalaya, India represents the easternmost limit of sal distribution. This will generate 2,000 random numbers that fit in a normal distribution. Shannon’s diversity index uses the natural log of pi not log base 10. of each species. For more information about creating charts, click Microsoft Excel Help on the Help menu, type create a chart in the Office Assistant or the Answer Wizard, and then click Search to view the topic. Beside the Simpson Index there are many other indices used to describe diversity.

In particular, for a random sample, we can use Shannon’s index of diversity (aka as Shannon-Weiner’s index), which is defined as, where ni is the number of observations from the sample in the ith of k (non-empty) categories and n = is the sample size. Using cover data for vegetation. J′ can be viewed as a measure of heterogeneity (or dominance). Charles. A bell curve is a plot of normal distribution of a given data set. You now have a chart that compares a given data set to a bell curve. Vegetation was sampled in 11 transects of 10 m width and up to 500 m length covering 5.2 ha area. It is common to consider the following measure of relative diversity (aka evenness or homogeneity): J′ can be viewed as a measure of heterogeneity (or dominance). Subscribe to Comments