OUR Ecological Footprint 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 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