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.
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.
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/