The measurement of biodiversity

What is biodiversity, how to measure biodiversity..and classification

1. THE MEASURE OF
BIODIVERSITY

2. How do we define ‘biodiversity’?
The sum of all biotic
variation from the
level of genes to
ecosystems.
The number, variety,
and variability of
living organisms in a
quantified area.

3. Methods to Measure
Biodiversity
Species Richness
Species Evenness
Disparity
Species Rarity
Genetic Variability.

4. Measuring Biodiversity…
Species Richness; the total number of given
species in a quantified area.
Species Evenness; the degree to which the
number of individual organisms are evenly divided
between different species of the community.
www.nature.com/cgi-tafwww.nature.com/cgi-taf

5. Measuring Biodiversity…
Disparity; measures the phenotypic differences
among species resulting from the differences
genes within a population.
Species Rarity; the rarity of individual organisms
within a quantified area.
http://www.rit.edu/~rhrsbi/GalapagosPages/DarwinFinch.html

6. Biodiversity & Genetics
Genetic Variability: each population of a species
contributes to additional biodiversity due to
variations between genes.
http://magma.nationalgeographic.com/ngm/bestwildlife/wallpaper13.html

7. Biodiversity and the
Relationship to Ecosystem
Functions
Diverse communities are typically more stable and
function more efficiently.
Loss of a umbrella species leads to a unoccupied niche,
in turn potentially affecting ecosystem processes.
Extinction events are commonly followed by high rates
of diversification. Ex) Species turnover

8. Productivity
Increase of productivity in an area corresponds with an
increase in biodiversity.
Ex) tropical rain forest compared to semi-desert or
tundra

9. Biodiversity & Exotic Species;
Ecosystems with high measures of biodiversity are more
resistant to invader species.
Ex) Cheatgrass & Tamarisk
http://tncweeds.ucdavis.edu/http://tncweeds.ucdavis.edu/photos

10. Keystone & Umbrella Species
Species whose presence or resource requirements affect
ecosystem functions.
Health of an umbrella species is a way to monitor the
health of an ecosystem.
Ex) Northern Spotted Owl & Grizzly Bears

11. Taxonomy
New Discoveries
Grouping together
Splitting apart
Phylogenies; showing past relationships between
organisms using evolutionary lineages.

12. Increasing Species Worldwide
Phylogenic Species Concept
Computer databases
Increased human exploration
Technology; electron microscope and evidence using
mDNA.

13. Species Richness
www.nature.com/cgi-tafwww.nature.com/cgi-taf

14. Taxonomic methods used in relation to
quantifying biodiversity
Phylogenic Species Concept
Biological Species Concept
Evolutionary Species Concept

15. Phylogenic Species Concept
taxa are separate species if they can be diagnosed as
distinct either by phenotypic or genotypic information.
Leads to an increase in the number of species.
Does not allow for natural variations within populations
to be listed as separate species.

16. Biological Species Concept
Groups of organisms that can interbreed freely under
natural conditions.
Most commonly used of the three

17. Evolutionary Species Concept
Groups organisms together using an
ancestral/descendant relationship that is traceable in
the fossil record
Focuses on studying the morphological features of
closely related organisms.

18. Problems in General
Measuring biodiversity is ultimately a
complex process involving many facets.
Various applications of species concepts
either divide and/or group organisms
together.
Biodiversity can’t be reduced to a single
number.
Studying biodiversity using all ecosystem
processes at all scales.
In attempting to preserve biodiversity we
often are ‘speciesists’ ;favoring the cute
and popular species.

19. Conclusions
Generally, areas of higher productivity
correlate with increases in biodiversity.
Biodiversity is also measured using the
genetic variability of different
populations of a single species.
Biodiversity can’t be reduced to a single
number, thus creating complications
when comparing biodiversity in different
ecosystems.
The importance of biodiversity is
accepted by some and disregarded by
many others.

20. QUESTIONS…
How do different taxonomic methods
create potential problems in measuring
biodiversity?
How do difficulties in measuring
biodiversity create complications for
policy makers and administrative
regulations?
Can we study all processes at all scales?

Why should anyone care
about‘biodiversity’ ?

21. REFERENCES;
 Purvis, Andy. Hector, Andy. May 2000. Getting the Measure of Biodiversity. Nature
Magazine. Vol.405 pgs 212-219. Berkshire, United Kingdom.www.nature.com/cgi-taf

 Wildland Invasive Species Team. July 2002.Vernal, UT. Retrieved on 10-26-02
http://tncweeds.ucdavis.edu/photos

 Macdonald, Glen. 2003. Biogeography; Introduction to Space, Time, and Life. New York.
John Wiley & Sons Inc.

 Sartore, Joel. 2002. National Geographic Society. Retreived
10-20-02 http://magma.nationalgeographic.com/ngm/bestwildlife/ wallpaper13.html

 Dr. Robert Rothman: Darwin’s Finches. Retrieved on 10-18-02.
http://www.rit.edu/~rhrsbi/GalapagosPages/DarwinFinch
 Paul Walker. Balam Na Project. Rainforest Preserve. 8-28-02
http://www.rainforest.org/projects/balamna/balamna.html
      Paul Williams, 2002 ”Biodiversity: Measuring the variety of nature and selecting the priority
areas for conservation.” London, 10/23/02, http://www.nhm.ac.uk/science/projects/worldmap/
     Bryant, Peter J., 2001, “Biodiversity and Conservation: A Hypertext book”. Irvine, 10/23/02,
http://darwin.bio.uci.edu/~sustain/bio65/Titlpage.htm#Table%20of%20contents
 Dooley, Laura Lee S., 1982-2002, “Biodiversity and Protected Areas”, Washington D.C.,
10/23/03, http://www.wri.org/biodiv/