Biodiversity.pdf conservation biology course

slides

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 that human 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 and Theia collision
•Life depended on chemosynthesis, Anaerobes dominated
•Photosynthesis
•O
2 increased gradually, Ozone
•Temp. decrease
•Uni. → multi.

7. •Variations, character displacement, fitness, heritability,
change in the gene pool – phyletic speciation/evolution
•Adaptive/evolutionary radiation (much greater biodiversity)

9. Variations in local biodiversity
•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: examines the factors that affect thespecies
richnessanddiversificationof isolated natural communities
S = cA
z

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
•Evenness and richness
•Uneven distribution:
–rare spp. – extinction
–Poor habitat – skewed distribution

14. Biodiversity indices
•Shannon index: H = -Σp
i*ln(p
i)
•Simpson index: C = Σ(p
i)
2
•Probablity of interspecific encounter: PIE’ = 1- C
•Hills diversity index: N
1 = 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 richness decreases, 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
•Product of α diversity of landscape communities and degree
of β differentiation among them
•(dS/dD)*[(g+l)/2]

18. Setting areas for conservation?

19. Relating disturbance to spp. 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 30.82 1 1.34 4
E 2 1 2.16 1 0.79 2 2.39 1

20. •High levels of each leads to rarity
–α rarity
–β rarity
–γ rarity

21. Problems with indices
•Inverse relation b/w spp. richness & evenness
SiteForest
distr.
rank
Hunting
pressure
rank
Shannon
index
Pielous
evenness
index
Margalafs
index of
richness
A 5 4 0.98 50.45 51.25 5
B 4 3 1.61 40.74 31.42 3
C 3 2 1.79 20.7 4 2.05 2
D 1 5 1.697 30.82 11.34 4
E 2 1 2.16 10.79 22.39 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 faunal analysis: endemism + taxic weight
rank sites based on # endemic gps. it has
I W P I W P

25. Non-census indicators

26. Areas - cover only 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.
Will protection of highly endemic areas protect high
biodiversity?