1. Life Histories and Tradeoffs

2. Tradeoffs
“If two processes require the use of a limiting resource, then allocation of the resource to one process requires de-allocation to the second.”

3. Key Stages in the Life-History of a Plant
Seed Maturation
Growth
Dispersal
Flowering
seed phase
Dormancy
Pollination
Germination

4. Growth in Plants

5. Growth Apical meristems
Source of plant elongation; often acting to suppress lateral growth from other nodes

6. Growth Apical meristems Axillary meristems at nodes
Gives rise to leaves and flowers; can also form lateral branches when not suppressed by apical meristem

7. Growth Apical meristems Axillary meristems at nodes Internodes
Growth between adjacent nodes

8. Growth Apical meristems Axillary meristems at nodes Internodes
Secondary growth
Cambium in many perennial plants (not monocots) allows them to increase in girth over time

9. Plant growth is generally a Modular Process

10. Clonal Growth

11. Forms of Clonal Growth
Phalanx
Guerilla

12. Modes of Foraging Behavior
Number of Branches (n)
Ramet size (S)
Internode length (l)
Shoot q
Branch angle (q)
Root

13. Optimal Foraging?
Nutrient Rich
Nutrient Poor
Nutrient Rich

14. Optimal Foraging: Rich HabitatX

15. Optimal Foraging: Poor HabitatX

16. Optimal Foraging through a Plastic Response

17. Predictions Nutrient Rich Habitat Nutrient Poor Habitat
Short internodes
Long internodes
Profuse branching
Few branches
Acute branch angles
Obtuse branch angles
High shoot:root
Low shoot:root

18. An Experimental Test of
Optimal Foraging

19. The plant: Glechoma hederacea
Slade, A. J., and M. J. Hutchings The effects of nutrient availability on foraging in the clonal herb Glechoma hederacea. Journal of Ecology 75:

20. General Growth Pattern

21. Experimental Design
Nutrient poor
Legend
Nutrient rich
Mixed

22. Predictions and Results Nutrient Rich Habitat Nutrient Poor Habitat
Short internodes
Long internodes
Profuse branching
Few branches
Many large ramets
Few small ramets
High shoot:root
Low shoot:root

23. Intermediate growth in all locations
Predictions and Results
Mixed Treatment
Nutrient Rich Areas
Nutrient Poor Areas
Intermediate growth in all locations
Short internodes
Long internodes
Profuse branching
Few branches
Many large ramets
Few small ramets
High shoot:root
Low shoot:root

24. What role does physiological integration play?
General Interpretation
Glecoma hederacea exhibits a plastic growth
response to nutrient conditions
This response is not localized, but represents an average to conditions encountered across the clone
What role does physiological integration play?

25. Physiological Integration through Movement of Resources
Xylem: Transport of raw materials, e.g., H and soil nutrients
Phloem: Transport of
products of photosynthesis

26. Experimental Examination of Integration through Xylem
Experimental design
Cut leaf off
Inject fuchsin dye into xylem
Price, E. A. C., C. Marshall, and M. Hutchings Studies of growth in the clonal herb Glechoma hederacea. I. Patterns of physiological integration. Journal of Ecology 80:35-38.

27. Experimental Examination of Integration through Xylem
Experimental results
Complex pattern of nutrient flow, depends on xylem architecture
Apparent unidirectional flow of nutrients
Leaf with dye
Leaf without dye

28. Experimental Examination of Integration through Phloem
Leaf labeled with 14C

29. Experimental Examination of Integration through Phloem
Resulting radiograph
Leaf labeled with 14C

30. Experimental Examination of Integration through Phloem
Interpretation
Photosynthate stays in leaf or is transported to young developing tissues
Source-sink relationship

31. General Interpretation of Experiments
Patterns of physiological integration can be shown
Resource sharing seems to be in the direction of younger ramets
Optimal foraging is an ideal that is only partially met

32. Forms of Asexual Reproduction in Plants

33. Clonal Growth (revisited)
Rhizome
Stolon
Bulbils
Suckers
Plantlets

34. Fragmentation: jumping cholla

35. Production of seeds with no fertilization
Agamospermy
Production of seeds with no fertilization

36. Key Stages in the Life-History of a Plant
Seed Maturation
Growth
Dispersal
Flowering
seed phase
Dormancy
Pollination
Germination

37. Sexual Reproduction in Plants

38. Typical Angiosperm Lifecycle
Alternation of generations
Sporophyte (2n)
Gametophytes (1n)

39. Typical Angiosperm Lifecycle
Alternation of generations
Sporophyte (2n)
Gametophytes (1n)
Fertilization

40. Gender Expression in Plants♂ ♀
Hermaphrodites

41. Sequential Hermaphrodism
Some plants change sex over time!
Jack-in-the-pulpet (Arisemea triphyllum)

42. Distribution of Flower Types