1. Geography 442 Biogeography
Dr. Christine M. Rodrigue

2. Shagbark hickory Carya ovata (large pores allow ice crystal damage < -40-45°C)

3. Northern red oak Quercus rubra (large pores, ice damage < - 49-45°C)

4. Quaking aspen Populus tremuloides (small pores, no ice damage)

5. Black mangove Avicennia germinans (limited by temperatures <20°C)

6. Saguaro Carnegiea gigantea

7. Saguaro Carnegiea gigantea

8. SaguaroCarnegiea gigantea (dots = weather stations never experiencing 36 hrs below freezing; X = stations that have)

9. Eastern phoebe Sayornis phoebe

10. Eastern phoebe: summer Sayornis phoebe (USGS Breeding Bird Survey) Multiple limits: timberline/permafrost, aridity, summer mean or max temperatures

11. Eastern phoebe: winter Sayornis phoebe (Christmas Bird Count) Small birds=high surface to volume=risk of not being able to eat enough of the much fewer bugs to survive < ~4°C)

12. Sugar maple Acer saccharum (limited by mean Jan < -18°C to N; mean Jul >27°C to S; < 50 cm precip in cooler N; <100 cm in warmer S)

13. Liebig's Law of the Minimum
If several factors are essential to the survival and growth of a plant, the one in scarcest supply will be the limiting factor