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![Biodiversity indices
• Shannon index: H = -Σpi*ln(pi)
• Simpson index: C = Σ(pi)2
• Probablity of interspecific encounter: PIE’ = 1- C
• Hills diversity index: N1 = e[H]
• Margalef: D= (S-1)/ln(N); S: # spp, N: # individuals in sample
Assumptions:
All individuals are randomly sampled
Population is indefinitely large, or effectively infinite
All species in the community are represented](https://image.slidesharecdn.com/biodiversity-250304185002-cc74a986/85/Biodiversity-pdf-conservation-biology-course-14-320.jpg)
![Gamma diversity
• Product of α diversity of landscape communities and degree
of β differentiation among them
• (dS/dD)*[(g+l)/2]](https://image.slidesharecdn.com/biodiversity-250304185002-cc74a986/85/Biodiversity-pdf-conservation-biology-course-17-320.jpg)
Biodiversity.pdf conservation biology course
- 1. Biodiversity assessment • RB1:4 & TB1:1 Objectives • Biodiversity definition and its measurement • Importance of and challenges in biodiversity assessment. • Rarity and endemism
- 2. Biodiversity "the connections thathuman beings subconsciously seek with the rest of life.“ “the passionate love of life and of all that is alive.”
- 3. • Measurable parameter •WWF: millions of plants, animals & µorg., the genes they contain and the intricate ecosys. they help to build into living env.
- 4. Biodiversity Source: Noss. 1990.Conservation Biology, 4: 355 - 364.
- 5. • Earth andTheia collision • Life depended on chemosynthesis, Anaerobes dominated • Photosynthesis • O2 increased gradually, Ozone • Temp. decrease • Uni. → multi.
- 7. • Variations, characterdisplacement, fitness, heritability, change in the gene pool – phyletic speciation/evolution • Adaptive/evolutionary radiation (much greater biodiversity)
- 9. Variations in localbiodiversity • Niche assembly theory: EC – limited membership assemblages of spp. – co-exist – strict niche partitioning • Dispersal assembly theory: EC –open non-eqlbrm assemblage that changes continuously, random dispersal and stochastic local extinction
- 10. Island biogeography: examinesthe factors that affect the species richness and diversification of isolated natural communities S = cAz
- 11. • Conservation biologist –aim spp. conservation • Species? –Morphological: easy to use –Biological: difficult Might not give same results – problems!
- 12. • Measuring spp.Diversity –α –β –γ
- 13. Alpha diversity • Evennessand richness • Uneven distribution: –rare spp. – extinction –Poor habitat – skewed distribution
- 14. Biodiversity indices • Shannonindex: H = -Σpi*ln(pi) • Simpson index: C = Σ(pi)2 • Probablity of interspecific encounter: PIE’ = 1- C • Hills diversity index: N1 = e[H] • Margalef: D= (S-1)/ln(N); S: # spp, N: # individuals in sample Assumptions: All individuals are randomly sampled Population is indefinitely large, or effectively infinite All species in the community are represented
- 15. As species richnessdecreases, the distribution of relative species abundance becomes steeper, and the common species become even more dominant” Dominance diversity curve θ = 2ρAV
- 16. Beta diversity • Spp.diversity among communities • Whittaker’s measurement: (S/α)-1 ; α – avg # spp. per site • Gives insight into: – Sensitivity of spp. in diff. communities to changing env. conditions – Interdependence of spp. – Measure the spp. loss/gain due to changing conditions
- 17. Gamma diversity • Productof α diversity of landscape communities and degree of β differentiation among them • (dS/dD)*[(g+l)/2]
- 18. Setting areas forconservation?
- 19. Relating disturbance tospp. diversity Site Forest distr. rank Hunting pressure rank Shannon index Pielous evenness index Margalafs index of richness A 5 4 0.98 0.45 1.25 B 4 3 1.61 0.74 1.42 C 3 2 1.79 0.7 2.05 D 1 5 1.697 0.82 1.34 E 2 1 2.16 0.79 2.39 Site Forest distr. rank Hunting pressure rank Shannon index Pielous evenness index Margalafs index of richness A 5 4 0.98 5 0.45 5 1.25 5 B 4 3 1.61 4 0.74 3 1.42 3 C 3 2 1.79 2 0.7 4 2.05 2 D 1 5 1.697 3 0.82 1 1.34 4 E 2 1 2.16 1 0.79 2 2.39 1
- 20. • High levelsof each leads to rarity –α rarity –β rarity –γ rarity
- 21. Problems with indices •Inverse relation b/w spp. richness & evenness Site Forest distr. rank Hunting pressure rank Shannon index Pielous evenness index Margalafs index of richness A 5 4 0.98 5 0.45 5 1.25 5 B 4 3 1.61 4 0.74 3 1.42 3 C 3 2 1.79 2 0.7 4 2.05 2 D 1 5 1.697 3 0.82 1 1.34 4 E 2 1 2.16 1 0.79 2 2.39 1 • Diff. indices diff values • Ecological value • Sampling bias/error • Human interference – edges increase
- 22. Phylogenetic diversity index •“taxonomic distinctness” - # & abundance of diff. taxonomic levels I: # groups to which each terminal taxon belongs Q: measure of taxonomic uniqueness W: standardized weight P: percentage contribution for each terminal taxon to total diversity
- 23. • Critical faunalanalysis: endemism + taxic weight rank sites based on # endemic gps. it has I W P I W P
- 25.
- 26. Areas - coveronly 2.3% of the Earth’s terrestrial surface, contain 50% of the world’s plant species and 42% of terrestrial vertebrates 1. Geographic-based approach : Biodiversity hotspots, endemic species
- 27. Lamoreux et al. Willprotection of highly endemic areas protect high biodiversity?