This document discusses biodiversity and methods for measuring biodiversity, including through the use of biodiversity indices. It defines biodiversity as the variety of living organisms present in a given ecosystem. It then explains different categories of biodiversity - alpha, beta, and gamma diversity. The document also discusses several commonly used biodiversity indices: species richness, Simpson's index, Shannon-Wiener index, and evenness. It provides formulas for calculating Simpson's and Shannon-Wiener indices and explains how to interpret the results. Overall, the document provides a overview of biodiversity and approaches for quantifying biodiversity through different indices.

1. Submitted by,
KONDURI ARUN
AEM-2018-20-06

2. INTRODUCTION:
 The term biodiversity was first coined by the entomologist E.O. WILSON
in 1986.
 Biodiversity is the heritage of million years of evolution.
 Diversity is a basic property of life.
 The striking feature of earth is the existence of life and the striking feature
of life is its diversity.

3. What is biodiversity?
In its simplest form, biological diversity is the variety of
different types of organisms present and interacting in an ecosystem.

4. BIODIVERSITY INDEX:
Introduction:
A diversity index is a mathematical measure of species diversity in a
community. Diversity indices provide more information about community
composition than simply species richness (i.e., the number of species present).

5. How do we measure biodiversity?
Use theoretical categories*
 Alpha
 Beta
 Gamma

6. Alpha diversity
 Diversity within a particular sample.
It refers to the average species diversity in habitat or specific area.
It is a local measure.

7. Beta Diversity
It refers to the ratio between local or alpha diversity and
regional diversity.
→ This is the diversity between two habitats or regions.

8. Gamma Diversity
It is a total diversity of landscape.
It is combination of both alpha and beta diversity.
 E.g. diversity of a forest landscape.

10. TYPES OF BIODIVERSITY INDICES:
1. Species richness
2. Simpson's index
3. Shannon-Wiener index
4. Evenness

11. 1. RICHNESS: It is the total number of species found in an environment or
sample. This is quantitative description.
Richness is a simple numerical count of the number of different
types of organisms present. Species richness is a count of the number of
species that are present. Taxonomic richness is a count of the number of
different taxons present. One would presume that more species equals
more diversity.
However, comparing two areas of equal species richness may
show that they are not equally diverse. For example, lets consider a list of
tree species in two forest ecosystems:

12. Community A Community B
Water Oak Water Oak
Post Oak Post Oak
Blackjack Oak Hickory
Live Oak Pine
Bur Oak Cedar Elm
Pin Oak Pecan
Hickory Black Walnut
Although each community has seven different species, in A all are within
the same genus (and thus the same family, order, class, and division), whereas in
B we have representatives of six genera, four families, two orders, two classes,
and two divisions. Clearly B is more diverse.

13. Richness tends to increase over area. In other words, a larger area
will harbor more different species, probably because of a larger variety of
microhabitats and resources. Additionally, sampling over a larger area
increases the chance of finding rare species.

14. 2.Simpson's Diversity Indices: Is the probability that two randomly
selected individuals belong to two different species/categories.
The term 'Simpson's Diversity Index' can actually refer to any one of
3 closely related indices.
a) Simpson's Index (D): measures the probability that two individuals
randomly selected from a sample will belong to the same species (or some
category other than species). There are two versions of the formula for
calculating D. Either is acceptable, but be consistent.
D =(n / N)2 (or)
n = the total number of organisms of a particular species
N = the total number of organisms of all species
The value of D ranges between 0 and 1.

15. With this index, 0 represents infinite diversity and 1, no diversity.
That is, the bigger the value of D, the lower the diversity. This is neither
intuitive nor logical, so to get over this problem, D is often subtracted
from 1 to give:
b) Simpson's Index of Diversity (1-D):
The value of this index also ranges between 0 and 1, but now, the
greater the value, the greater the sample diversity. This makes more sense.
In this case, the index represents the probability that two individuals
randomly selected from a sample will belong to different species.
Another way of overcoming the problem of the counter-intuitive
nature of Simpson's Index is to take the reciprocal of the Index:

16. a) Simpson's Reciprocal Index (1/D):
The value of this index starts with 1 as the lowest possible
figure. This figure would represent a community containing only one
species. The higher the value, the greater the diversity. The maximum
value is the number of species (or other category being used) in the
sample. For example if there are five species in the sample, then the
maximum value is 5.

17.  The name 'Simpson's Diversity Index' is often very loosely applied and all three related indices
described above (Simpson's Index, Simpson's Index of Diversity and Simpson's Reciprocal
Index) have been quoted under this blanket term, depending on author. It is therefore
important to ascertain which index has actually been used in any comparative studies of
diversity.
To calculate Simpson's Index for a particular area, the area must first be sampled. The
number of individuals of each species present in the samples must be noted.
For example, the diversity of the ground flora in a woodland, might be tested
by sampling random quadrants. The number of plant species within each quadrat, as well as the
number of individuals of each species is noted. There is no necessity to be able to identify all the
species, provided they can be distinguished from each other.

18. Simpson’s index scale: level of biodiversity
1 No diversity
0.9 Extremely low diversity
0.8 Very low biodiversity
0.7 Low biodiversity
0.6 Moderate low biodiversity
0.5 Moderate diversity
0.4 Moderate high diversity
0.3 High diversity
0.2 Very high diversity
0.1 Extremely high diversity
0 Infinite diversity

19. 3. SHANNON INDEX: Methods: The Shannon diversity index (H) is
another index that is commonly used to characterize species diversity in a
community. Like Simpson's index, Shannon's index accounts for both
abundance and evenness of the species present.
The Shannon index has been a popular diversity index in the
ecological literature, where it is also known as Shannon's diversity index,
the Shannon-Wiener index, the Shannon entropy.

20.  Shannon Wiener Index:
s
H’ = -∑pi logepi
i=l
H’ = Value of SW diversity index.
 pi = Proportion of the ith species.
 loge = Natural logarithm of pi.
 s = Number of species in community.
Typical values are generally between 1.5 and 3.5 in most ecological
studies, and the index is rarely greater than 4. The Shannon index
increases as both the richness and the evenness of the community
increase.

21. 4. EVENNESS: This is a qualitative measurement.
is a measure of how similar the abundance of different
species/categories are in a community. evenness is ranged from zero to
one. When evenness close to zero, it indicates that most of the individuals
belongs to one or a few species/categories . when the evenness is close to
one, it indicates that each species/categories consists of the same number
of individuals.
Evenness is a measure of the relative abundance of the different
species making up the richness of an area.

22. NUMBER OF INDIVIDUALS
Flower species SAMPLE -A SAMPLE-B
Daisy 300 20
Dandelions 335 49
Buttercup 365 931
total 1000 1000
As species richness and evenness increase, so diversity
increases. Simpson's Diversity Index is a measure of
diversity which takes into accounts both richness and
evenness.

23. To give an example, we might have sampled two different fields
for wildflowers. The sample from the first field consists of 300 daisies, 335
dandelions and 365 buttercups. The sample from the second field
comprises 20 daisies, 49 dandelions and 931 buttercups (see the table
below). Both samples have the same richness (3 species) and the same
total number of individuals (1000). However, the first sample has more
evenness than the second. This is because the total number of individuals
in the sample is quite evenly distributed between the three species. In the
second sample, most of the individuals are buttercups, with only a few
daisies and dandelions present. Sample 2 is therefore considered to be less
diverse than sample 1.

24. Biodiversity indices uses:
 A biodiversity index is a way of measuring biodiversity.
 To restore and maintain the chemical , physical & biological integrity of
the ecosystem.
 Diversity indices provide important information about rarity and
commonness species in a community.

25. REFERENCE:
 Https://en.wikipedia.org/wiki/Diversity_index
 http://www.tiem.utk.edu/~gross/bioed/bealsmodules/shannonDI.html
 http://aquafind.com/articles/Biodiversity-Indices.php

26. THANK YOU