GETTING THE MEASURE OF BIODIVERSITY

1. GETTING 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-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 http://www.rainforest.org/projects/balamna/balamna.html

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-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/

22. Happy Halloween