Transcript Wilkins PPT

Coral Reef Biodiversity
Biodiversity
The variety of the earth’s species, the genes they
contain, the ecosystems in which they live and
the ecosystem processes.
Biodiversity is a vital natural
resource
Basic Concepts of Biological
Diversity
Genetic diversity:
total # of genetic characteristics.
Habitat diversity:
total # different kinds of habitat in a given unit area.
Species diversity:
total # of a specific species, sub species or group
of species
10 species; 100 ind, 87 elephants, 9 sp w/ 2 ind each
10 species; 100 ind, 10 ind each species
Species Diversity
Merely counting the number of species is not enough
to describe biological diversity.
Basic Concepts of Biological
Diversity
Genetic diversity:
total # of genetic characteristics of a specific
species, sub species or group of species.
Habitat diversity:
the different kinds of habitat in a given unit area.
Species diversity:
Species richness- total # of sp
Species evenness- the relative abundance of sp
Species dominance- the most abundant sp
Diversity Index
A diversity index is a mathematical measure of
diversity in a community.
Important to select area, understand what you are
counting and be familiar with the organisms in
order to do a DI
What is the Diversity Index of that forest?
Species Richness
(diversity)
Species richness not very informative
Each community has 5 spp & 50 individuals
Spp1
Comm
A
10
Spp
2
10
Comm
B
46
1
Spp
3
10
Spp
4
10
Spp
5
10
1
1
1
Take a few minutes to look over the spread sheet
You will observe data gathered on 3 different
ecosystems.
1. Write down 3 observations
2. Which ecosystems are more diverse; those
with larger DI numbers or smaller ? Explain
Take a few minutes to look over the spread sheet
Write down 3 observations
1. Which ecosystems are more diverse; those with larger DI
numbers or smaller ? Explain
2. Compare Ecosystems A and B- How do their indices compare?
Each has 10 different species, Ecosystem A has only 29
organisms and Ecosystem B has over 300
Which has a healthier Diversity Index? Why
4. Compare the last two Ecosystem indices. What do you notice?
DI
Sample
A
pop.
DI
B
pop.
DI
C
pop.
DI
29
0.1058
311
0.1067
4400
0.1209
Species 1
2
0.0048
23
0.0055
100
0.0005
Species 2
3
0.0107
23
0.0055
200
0.0021
Species 3
4
0.0190
34
0.0120
500
0.0129
Species 4
3
0.0107
22
0.0050
600
0.0186
Species 5
2
0.0048
33
0.0113
400
0.0083
Species 6
3
0.0107
44
0.0200
700
0.0253
Species 7
4
0.0190
33
0.0113
600
0.0186
Species 8
2
0.0048
22
0.0050
300
0.0046
Species 9
3
0.0107
33
0.0113
700
0.0253
Species 10
3
0.0107
44
0.0200
300
0.0046
Totals
Diversity indices
To get a better description of the community we
need to get a measure of spp richness and
evenness of their distribution
Diversity indices
Over 60 indices used in ecology
Indices used to measure proportional abundance
Two major forms:
Dominance indices (e.g. Simpson index)
Information indices (e.g. Shannon Weiner index)
Simpson Diversity
Index (D)
It takes into account the number of species present, as well
as the relative abundance of each species
D ranges from 0 to 1, with 0 representing infinite diversity and 1
representing no diversity
Simpson Diversity
D = (n (n -1)/N(N-1))
Index (D)
s
1
1
Where:
Ds = Bias corrected form for Simpson Index
n1 = number of individuals of spp 1
N = Total number of spp in community
In this form as diversity increases index value gets
smaller
Simpson
Sugar Red YelloDiversity
Red White Total
w
Maple Maple
Oak
Ash
Index
(D)
Birch
#
Trees
56
48
12
6
3
((56*55)/(125*124))+
((48*47)/(125*124)) + ………….
….((3*2)/125*124)) = 0.35509
125
Diversity Lab
DIRECTIONS:
In this activity your "ecosystem" will be the
school parking lot, and the "species" will be
the different car models and colors. As a
class, we will be comparing the species
diversity of the student and staff parking
lots.
Quadrat Sampling
•
Students analyze images of two different reefs and make a hypothesis on the rate the health of each.
•
Transect studies are used to determine the biodiversity of two areas.
In order to compare the two reef systems a line or path is used for sampling. A ten meter transect in the field is transferred to every 12 inches in the
classroom
•
Students determine and classify the number and type of corals quadrat sampling method in the classroom.
•
Just because there are the same number of total organisms and species in two areas does not mean that they have the same biodiversity.
•
Conclusion should be made once data is collected. The hypothesis analyzed and new hypothesis typically formed based on the data.
Quadrat Sampling
Estimating percent cover on the benthos using a metre-square quadrat
with string or fishing line strung across at 10 cm intervals.
Transect and
Quadrat Sampling
Habitat A
Common Coral Group
HARD
CORALS
GORGON
IANS
Medium- Rusty Medium- Brown
G-Rust
G-Brow
SOFT
CORALS
S-Tree
Orange Tree Coral
Dendronephthya genus
H-Eleg
Elegance Coral (Catalaphyllia jardinei)
Ricordea Mushroom
S-Rico
Acropora Staghorn Coral
Brain coral
H-Stag
family Faviidae
H-Brai
Coral
Zoanthus Eagle Eye
Grou
S-ZoEy
p
Coun
Zoanthus S-ZoBr
Cyanobacteria covering coral
ted if
<1cm
H-EuGr Green Hammer Coral Euphyllia H-EuBR Brown
Habitat B
A
1
3
2
B
C
Conclusion Quadrat
Sampling
• Just because there are the same number of total organisms and species in two areas
does not mean that they have the same biodiversity.
• Conclusion should be made once data is collected. The hypothesis analyzed and new
hypothesis typically formed based on the data.
Earth is home to a tremendous
diversity of species
•
•
•
Ecosystem diversity- the variety of
ecosystems within a given region.
Species diversity- the variety of species in
a given ecosystem.
Genetic diversity- the variety of genes
within a given species.
Niches
•
•
•
Realized niche- the range of abiotic and biotic
conditions under which a species lives. This
determines the species distribution, or areas of the
world where it lives.
Niche generalist- species that live under a wide
range of conditions.
Niche specialist- species that live only in specific
habitats.
The Fossil Record
• Fossils- remains of organisms that have
been preserved in rock. Much of what
we know about evolution comes from
the fossil record.
The Five Global Mass Extinctions
•
Mass extinction- when large numbers of
species went extinct over a relatively
short period of time.
The Sixth Mass Extinction
•
•
•
Scientists feel that we are in our sixth
mass extinction, occurring in the last two
decades.
Estimates of extinction rates vary widely,
from 2 % to 25% by 2020.
In contrast to previous mass extinctions,
scientists agree that this one is caused by
humans.