Adaptive Leaf Size Week Two (analysis)

1. Adaptive Leaf SizeWeek Two (analysis)

2. Hypotheses: • H1: Plants in wet soil do not have to conserve water, so they will be as warm as possible to maximize photosynthesis. • H2: Plants in dry soil must conserve water, so they will be as cool as possible. • Predictions :

3. Wet Dry Predictions: In the sun, a leaf can be warmed above the air temp by the sun, so this leaf should be large to increase photosyn.: stay hot In the sun, the air temp is the coolest the leaf can be, so this leaf should be small to reach air temp and conserve water: get cool Sunny In the shade, the leaf can get below air temp (due to evaporative cooling), so this leaf should be large to conserve water: stay cool In the shade, the air temp is as warm as the leaf can be, so this leaf should be the air temp to increase photosyn.: get hot Shady Decrease water loss Increase photosynthesis

4. Assumptions: •  Temperature :  Photosynthesis (to a point) •  Temperature :  Water loss

5. We will do 4 t-tests • Don’t forget where you predicted the larger vs. smaller leaf! Fun with Statistics!

6. t-test… t = t-test value X = group mean s = st. dev. n = sample size

7. According to the model, what environmental factors determine leaf size? • What other environment factors could influence leaf size? • Why is the model applied to vine-like plants? • What assumptions did you make to test the model? • Do you think they were valid? • Which lab measurements were: • Qualitative? • Quantitative? Food for thought…

8. What is important in the wet habitat? What is important in the dry habitat? Wet Dry Sunny Shady

9. Wet Dry Sunny Shady Increase photosynthesis Decrease water loss

10. Wet Dry Sunny Shady Decrease water loss Increase photosynthesis

11. Wet Dry Sunny Shady Decrease water loss Increase photosynthesis

12. Wet Dry Sunny Shady Decrease water loss Increase photosynthesis