1. Controls: climate

2. Controls: soils, parent material

3. Controls: topography

4. Controls: disturbance

5. <0.01% of pre-settlement prairie in Illinois remains
Controls: humans
<0.01% of pre-settlement prairie in Illinois remains
Self-scouring, steel-bladed plow

6. Controls: herbivory

7. Controls: microclimate

8. Controls are not constant; they have changed through time
For example:
Continental drift
Mountain building and rain shadows
Climate change
Human alteration to land cover; greenhouse gas emissions

9. Biomes during last glacial maximum

10. Trees following last glacial maximum

11. Latitudinal movement of the solar equator causes seasons

12. Solar equator moves seasonally

13. Seasonal cycles in temperate lakes13

14. Variation in temperature generates winds.
Winds drive ocean currents, which redistribute heat and moisture.
clockwise
counter-
clockwise
upwelling

15. Upwelling currents bring cold, nutrient-rich water to the surface & lead to high productivity

16. 16

17. 17

18. Effects of El Niño on climate18

19. Effects of El Niño on crop production

20. Stronger El Niño events in recent decades

21. Fundamental niches and climatic envelopes for hypothetical 20th- and 21st-century climates
Shifts in distributions (1-3)
Community
disaggregation (1 & 3)
New communities (2 & 3)
Extinction (4)
Williams et al PNAS.

22. Maps of novel 21st-century climates and disappearing 20th-century climates
12-39%
4-20%
10-48%
4-20%
Assumes no dispersal limitation; w/ disperal limitation the %s approx. double
Williams et al PNAS.

23. Summary
Ecosystems are complex, resulting from many interacting factors
Ecosystems and their controls are not constant; they have changed through time
Humans now have a dominant influence on Earth’s climate and ecosystems
The present helps us interpret the past and anticipate future changes