Lec 3 - BIS2B Fall 2008 Monday Sept 25 Lecture 3 Welcome to...

Welcome to BIS 2B
Evolution and Ecology
BIS2B, Fall 2008
Monday Sept 25.
Lecture 3.
Biological Diversity,
the variety of life on earth.
Geographical & Functional
Diversity

Some of what we learned about biodiversity
from the Video?
a.Most species occur in at high latitude.
b.High biodiversity is correlated with high
latitude.
c.Low latitudes are next to the ocean
d.Low latitudes are where biodiversity is
concentrated.
e.Low latitudes are especially dangerous
places.

Species differ in relative abundance. Some are common,
some are of intermediate abundance, some are rare.
This means that rank-abundance plots slope downward, from
the upper right to the lower left, from the most abundant to
the least abundant species. (If all species were of equal
abundance, the rank-abundance plot would be horizontal).
Large sample sizes are necessary to approach the asymptote
of species diversity in many ecosystems.
The common species are several orders of magnitude more
abundant than the rare species.
This necessitates plotting log abundance versus species rank
in order to visualize the relationships between the orders of
magnitude.

Plotting with logs to reveal orders of magnitude
difference in abundance between species .
Log
10
1 = 0
Log
10
2 to 10 >0 to 1
Log
10
10 to 100 ranges from 1 to 2
Log
10
100 to 1000 ranges from 2 to 3
Log
10
1000 to 10,000 ranges from 3 to 4
Log
10
10,000 to 100,000 ranges from.. You tell me!

Rank –Abundance plots of high species diversity.
Using logs to meet the challenge of multiple orders of magnitude.
Korup Forest, Cameroon. 495 species of trees.

Deciduous forest. 5 species of trees.