GETTING THE MEASURE OF GETTING THE MEASURE OF BIODIVERSITYBIODIVERSITY

How do we define ‘biodiversity’?How do we define ‘biodiversity’?

The sum of all The sum of all biotic variation biotic variation from the level of from the level of genes to genes to ecosystems.ecosystems.

The number, The number, variety, and variety, and variability of living variability of living organisms in a organisms in a quantified area.quantified area.

Methods to Measure Methods to Measure BiodiversityBiodiversity

Species RichnessSpecies Richness Species EvennessSpecies Evenness DisparityDisparity Species RaritySpecies Rarity Genetic VariabilityGenetic Variability. .

Measuring Biodiversity…Measuring Biodiversity… Species RichnessSpecies Richness; the total number of given species in a ; the total number of given species in a

quantified area.quantified area. Species EvennessSpecies Evenness; the degree to which the number of ; the degree to which the number of

individual organisms are evenly divided between different individual organisms are evenly divided between different species of the community.species of the community.

www.nature.com/cgi-tafwww.nature.com/cgi-taf

Measuring Biodiversity…Measuring Biodiversity… DisparityDisparity; ; measures the phenotypic differences among measures the phenotypic differences among

species resulting from the differences genes within a species resulting from the differences genes within a population.population.

Species RaritySpecies Rarity; the rarity of individual organisms within a ; the rarity of individual organisms within a quantified area.quantified area.

http://www.rit.edu/~rhrsbi/GalapagosPages/DarwinFinch.html

Biodiversity & GeneticsBiodiversity & Genetics Genetic Variability:Genetic Variability: each population of a species each population of a species

contributes to additional biodiversity due to variations contributes to additional biodiversity due to variations between genes. between genes.

http://magma.nationalgeographic.com/ngm/bestwildlife/wallpaper13.html

Biodiversity and the Relationship to Biodiversity and the Relationship to Ecosystem FunctionsEcosystem Functions

Diverse communities are typically Diverse communities are typically more stable and function more more stable and function more efficiently.efficiently.

Loss of a umbrella species leads to a Loss of a umbrella species leads to a unoccupied niche, in turn potentially unoccupied niche, in turn potentially affecting ecosystem processes.affecting ecosystem processes.

Extinction events are commonly Extinction events are commonly followed by high rates of followed by high rates of diversification. Ex) Species turnoverdiversification. Ex) Species turnover

ProductivityProductivity

Increase of productivity in an area corresponds Increase of productivity in an area corresponds with an increase in biodiversity.with an increase in biodiversity.

Ex) tropical rain forest compared to semi-desert Ex) tropical rain forest compared to semi-desert or tundraor tundra

http://www.rainforest.org/projects/balamna/balamna.html

Biodiversity & Exotic Species;Biodiversity & Exotic Species;

Ecosystems with high measures of Ecosystems with high measures of biodiversity are more resistant to biodiversity are more resistant to invader species.invader species.

Ex) Cheatgrass & TamariskEx) Cheatgrass & Tamarisk

http://tncweeds.ucdavis.edu/ http://tncweeds.ucdavis.edu/photos

Keystone & Umbrella SpeciesKeystone & Umbrella Species

Species whose presence or resource Species whose presence or resource requirements affect ecosystem requirements affect ecosystem functions. functions.

Health of an umbrella species is a Health of an umbrella species is a way to monitor the health of an way to monitor the health of an ecosystem.ecosystem.

Ex) Northern Spotted Owl & Ex) Northern Spotted Owl & Grizzly Bears Grizzly Bears

Taxonomy Taxonomy

New DiscoveriesNew Discoveries Grouping togetherGrouping together Splitting apartSplitting apart Phylogenies; showing past Phylogenies; showing past

relationships between organisms relationships between organisms using evolutionary lineages.using evolutionary lineages.

Increasing Species WorldwideIncreasing Species Worldwide

Phylogenic Species ConceptPhylogenic Species Concept Computer databasesComputer databases Increased human explorationIncreased human exploration Technology; electron microscope Technology; electron microscope

and evidence using mDNA.and evidence using mDNA.

Species RichnessSpecies Richness

www.nature.com/cgi-tafwww.nature.com/cgi-taf

Taxonomic methods used in Taxonomic methods used in relation to quantifying relation to quantifying

biodiversitybiodiversity Phylogenic Species ConceptPhylogenic Species Concept Biological Species ConceptBiological Species Concept Evolutionary Species ConceptEvolutionary Species Concept

Phylogenic Species ConceptPhylogenic Species Concept

taxa are separate species if they can taxa are separate species if they can be diagnosed as distinct either by be diagnosed as distinct either by phenotypic or genotypic information.phenotypic or genotypic information.

Leads to an increase in the number Leads to an increase in the number of species.of species.

Does not allow for natural variations Does not allow for natural variations within populations to be listed as within populations to be listed as separate species.separate species.

Biological Species ConceptBiological Species Concept

Groups of organisms that can Groups of organisms that can interbreed freely under natural interbreed freely under natural conditions. conditions.

Most commonly used of the threeMost commonly used of the three

Evolutionary Species ConceptEvolutionary Species Concept

Groups organisms together using an Groups organisms together using an ancestral/descendant relationship ancestral/descendant relationship that is traceable in the fossil recordthat is traceable in the fossil record

Focuses on studying the Focuses on studying the morphological features of closely morphological features of closely related organisms.related organisms.

Problems in GeneralProblems in General Measuring biodiversity is ultimately a complex Measuring biodiversity is ultimately a complex

process involving many facets.process involving many facets. Various applications of species concepts either Various applications of species concepts either

divide and/or group organisms together.divide and/or group organisms together. Biodiversity can’t be reduced to a single Biodiversity can’t be reduced to a single

number.number. Studying biodiversity using all ecosystem Studying biodiversity using all ecosystem

processes at all scales.processes at all scales. In attempting to preserve biodiversity we often In attempting to preserve biodiversity we often

are ‘speciesists’ ;favoring the cute and popular are ‘speciesists’ ;favoring the cute and popular species.species.

Conclusions Conclusions

Generally, areas of higher productivity Generally, areas of higher productivity correlate with increases in biodiversity.correlate with increases in biodiversity.

Biodiversity is also measured using the Biodiversity is also measured using the genetic variability of different populations genetic variability of different populations of a single species. of a single species.

Biodiversity can’t be reduced to a single Biodiversity can’t be reduced to a single number, thus creating complications when number, thus creating complications when comparing biodiversity in different comparing biodiversity in different ecosystems.ecosystems.

The importance of biodiversity is accepted The importance of biodiversity is accepted by some and disregarded by many others.by some and disregarded by many others.

QUESTIONS…QUESTIONS…

How do different taxonomic methods create How do different taxonomic methods create potential problems in measuring potential problems in measuring biodiversity?biodiversity?

How do difficulties in measuring biodiversity How do difficulties in measuring biodiversity create complications for policy makers and create complications for policy makers and administrative regulations?administrative regulations?

Can we study all processes at all scales?Can we study all processes at all scales?

Why should anyone care about‘biodiversity’ Why should anyone care about‘biodiversity’ ??

REFERENCES;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/

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