Download Lab this week: Go to computer room!! Next lecture: Finish with Ch 23

OUR Ecological Footprint - 13
1. Recycle; pay tax for it.
2. Live near work; ride bike; minimize car use.
3. Buy energy-efficient furnace.
4. Programmable thermostat: winter/summer
5. Turn off lights when leave room; unplug appliance
6. Eat lower on food chain.
7. Buy foods locally; avoid transport/energy costs.
8. Use energy-efficient light bulbs.
9. Reduce paper/plastic (and ALL) consumption.
10. Reduce garbage + consumption of paper/plastic.
11. Be a selective fish eater.
12. Lengthen cycle of resource use; wear it out!
13. Change lifestyle of greater consumption towards
a lifestyle based on voluntary simplicity…
‘ENRICH YOUR RESUME’…
• THIS THURSDAY 4-5
• 217 NOYES LAB
• IB students describe ‘out-of-class’
opportunities
• Obtain info on how to find out about
these, when/how to apply
Last lab…
3rd Annual Ecology Symposium
Lab/TA evaluation
Chapter 25: Extinction +
Conservation
Chapter 23
Biodiversity
Chapter 24
History and
Biogeography
Objectives
•
•
•
•
•
•
•
•
•
Species diversity: different geographical scales
Factors at local vs. regional scales
Equilibrium theories of species diversity
Island Biogeography Theory
Regional-scale species diversity
Patterns and causes
Effect on local diversity
Latitudinal-scale species diversity
Continental/global scale and role of history
Equilibrium in s.d. over time?
Continental drift:
separation, joining, and biotic exchange
Role of climatic change
Multiple scales of species diversity
•
•
•
•
•
Local
Regional
Latitudinal
Continental
Global
• Ecological vs. Evolutionary Time…
• Role of history
Many factors influence local and regional
species diversity
Multiple scales of species diversity
•
•
•
•
•
Local
Regional
Latitudinal
Continental
Global
Equilibrium theories: diversity reflects a
balance between processes that add vs.
remove species.
• ***What processes add species?
• speciation
• immigration
• What processes subtract species?
•
extinction
•
emigration
• Differences in diversity between
communities reflect differences in relative
rates of these processes.
Equilibrium theory in continental communities:
balance between speciation and extinction on
regional scale
Equilibrium theory of island biogeography:
# species = balance of immigration on a
regional scale vs. extinction on local scale.
Islands closer to the mainland support more
species because of higher immigration rates.
Larger islands support more species
because of lower extinction rates.
*** What is the pattern? What explains it?
***Why do smaller islands have fewer species?
*** Do experimental results support ETIB?
Applications of Island Biogeography
Theory (IBT) to:
• Terrestrial systems
e.g. mountain tops as islands
fragmented remnants as
islands
• Design of nature reserves
Regional-scale patterns of diversity
reflect:
• Habitat heterogeneity
• Suitability of physical conditions
• Isolation from centers of diversity
***What are three patterns in species
diversity? What factor accounts for each
pattern?
Comparing diversities of communities in
similar habitats in different regions can
reveal regional effects.
Saturation of local communities: test
how local and regional diversity relate.
Variation in local species diversity
depends on regional diversity.
***Are local
communities
saturated?
***What are major changes among
regions from Tertiary to present? What
accounts for them?
Mangrove vegetation is less diverse in the
New World than the Old World tropics.
• Mangrove
vegetation
occupies a
greater
ecological range
where it is most
diverse.
Multiple scales of species diversity
•
•
•
•
•
Local
Regional
Latitudinal
Continenta
Global
***What is latitudinal gradient in woody
species diversity? What explains it?
Hypotheses to explain latitudinal gradient
in species diversity
•
•
•
•
•
•
•
•
•
Time
Energy
Productivity
Heterogeneity in space and time
(Vegetation and food complexity)
Predation
Competition/niches
Disturbance
Equilibrium models
Time hypothesis
• Tropics are older (and less disturbed??) --->more
time to accumulate species.
• What happened to climate in the tropics during
glaciation?
• What happened to species in the tropics during
glaciation?
•
Increased speciation from fragmentation?
•
Did extinction increase?
Many factors influence regional and local
species diversity
Multiple scales of species diversity
•
•
•
•
•
Local
Regional
Latitudinal
Continental
Global
Equilibrium theories: diversity reflects a
balance between processes that add vs.
remove species.
• Add species:
•
speciation
•
immigration
• Subtract species:
•
extinction
•
emigration
• Has regional species diversity been constant
(in equilibrium) over long periods of time?
How do history + biogeography influence
local communities and sp. diversity?
History of life is gauged by geologic time
scale.
***Has diversity been constant?
Catastrophes --> major changes in
direction of evolution
Asteroid
impact-->
extinctions
Continental drift --> positions of
continents change over geologic time.
Continental drift changed routes of
dispersal via separation + joining.
Exchanges of biotas after joining of
continents: e.g. The Panama land bridge
Lineages of ratite birds separated by
fragmentation of Gondwana.
Organisms are not distributed uniformly
over earth.
Phylogenetic effects
• traits shared by lineage irrespective of
environment
• e.g. marsupial model of reproduction
due to lineage of evolution
not due to environment in Australia
Wallace: Major zoogeographic regions
reflect long-term evolutionary isolation.
In contrast, similar environments among
regions leads to convergent evolution.
Similar
solutions to
common
problems…
How climatic
history
determines
species
distributions
Climate change shifts species diversity.
Local diversity as f(continental diversity).
Objectives
•
•
•
•
•
•
•
•
•
Species diversity: different geographical scales
Factors at local vs. regional scales
Equilibrium theories of species diversity
Island Biogeography Theory
Regional-scale species diversity
Patterns and causes
Effect on local diversity
Latitudinal-scale species diversity
Continental/global scale and role of history
Equilibrium in s.d. over time?
Continental drift:
separation, joining, and biotic exchange
Role of climatic change
Vocabulary
Chapte r 24 History and Biogeography
phy logenetic effects
Laurasia
Nearctic
Australian
mass extinctions
continental d rift
Gondwan a
Palearctic
Oriental
land bridges
Pangaea
vicariance
Ethiopian
Neotropical
convergence
Chapte r 23 Biodiversity
equi lbrium theory
local diversity
species sorting
alpha diversity
delta diversity
niche b readth
realized niche
inte rmediate disturbanc e
Island biogeography theory regional diversity
habita t selection
environmental filters
species pool
ecological release
beta dive rsity
gamma diversity
niche space
niche axis
niche overlap
funda mental niche
potential evapot ranspiration
pest pressure
recruitment limitation