Chapter 7 Energy relations

1. Chapter 7 Energy relations Energy sources and trophic biology: light, organic molecules, or inorganic molecules

2. Announcements? • Meetings?

3. Energy sources and trophic biology • Photosynthesis = autotrophic • Plants, bacteria, protists

4. Energy sources and trophic biology • Chemosynthesis = autotrophic • Bacteria

5. Energy sources and trophic biology • Consume organic matter = heterotrophic • Bacteria, fungi, protists, animals, plants

6. Trophic diversity across biological kingdoms Figure 7.2

7. 3 biochemical pathways for photosynthesis: • C3 • In dry environments: • C4 • CAM

8. Different photosynthesis types in different environments - C3 • Cool/moist, low light environ • Energy efficient • Less efficient water use • Less efficient CO2 uptake

9. Different photosynthesis types in different environments - C4 • Hot/dry, high light environ • Less energy efficient • More efficient water use • More efficient CO2 uptake

10. Different photosynthesis types in different environments - CAM • Desert - succulents • Less energy efficient • Most efficient water use • Efficient CO2 uptake at NIGHT

11. Energy Relations In Plants(All measured by CO2 flux) • Gross Photosynthesis (Pgross ) • Total amount of CO2 fixed into glucose • Respiration (R) • Total amount of glucose utilized for energy • Net Photosynthesis (Pnet ) • Pgross- R

12. Generalized Light Response Curve Pnet (= Pgross- R) + 0 - Irradiance Compensation Point Saturation Point

13. Figure 7.21 Contrasting photosynthetic response curves

14. Light response curve: • 1 = range of irradiance where P limited by low light

15. Light response curve: • 2 = optimum irradiance (max Pnet)

16. Light response curve: • 3 = range of irradiance where P limited by high light; breaks down photosynthetic apparatus faster than repaired

17. Light Response Curves C4 Plant Species Sugar Cane Sorghum Corn Pnet (= Pgross- R) C3 Plant Species Trees Wheat Algae + 0 C3 Species Have Higher Pnet in Low Light - Irradiance

18. Light response curve for different species

19. Generalized Nutrient Response Curve Growth Rate Saturation <<<< Deficiency >>>> Toxicity >>>> Optimum Nutrient Concentration

20. Nutrient Response Curves Micro- Nutrient Fe Mn Zn Cu Mo B Cl . . Macro- Nutrient C O H P K N S Mg Ca Required in small quantities Become toxic at higher concentrations Required in large quantities Rarely toxic at concentrations that occur in Nature Growth Rate Nutrient Concentration

21. Energy/nutrients usually in limited supply • Environment-plant relations: • Photosynthesis only with appropriate T, light, water, nutrients (based on climate/soil)

22. Energy/nutrients usually limited supply • Plant-Herbivore relations • Plants are numerous • Easy to find, catch • Low nutritional value • Available seasonally

23. Energy/nutrients usually limited supply • Plant-Herbivore relations • Plants use physical and chemical defenses • Thorns • Toxins • Digestion-reducing compounds

24. Energy/nutrients usually limited supply • Predator-Prey relations: • Prey animals less numerous than plants • difficult to find, catch • Higher nutritional value

25. Energy/nutrients usually limited supply • Predator-Prey relations: • Evolution of defenses by plants and prey animals • NS pressure on herbivores/predators to evolve alternative methods

26. Energy/nutrients usually limited supply • Detritivores: • Majority of food plant material

27. Predation 1 search 2 recognition 3 catching 4 consumption

28. Pred activity Searching Pred adaptation Sensory acuity Search where prey are abundant Search image Table of adaptations • Prey counter-adaptation • Improved sensory acuity • Space out • Polymorphism

29. Table cont. • Pred activity • Recognition of prey • Pred adaptation • Learning • Prey counter-adaptation • Warning signals, mimicry

30. Table cont. • Pred activity • Catching • Pred adaptation • Improved motor skills • Weapons of offense • Prey counter-adaptation • Improved motor skills, startle responses, aggregation formation • Weapons of defense

31. Table cont. • Pred activity • Handling prey • Pred adaptation • Subduing skills • Detoxification ability • Prey counter-adaptation • Active defense, tough integument, autotomy • Toxins

32. Anglerfish: Frogfish: Cryptic against rocky background. Lure to attract prey.

33. Harris Hawk To detect small prey, extremely good eyesight. For capturing prey, has sharp beak and talons.

34. SEA ANEMONES - poisonous tentacles. Counter-adaptation, CLOWNFISH coat themselves with chemical inhibitor -prevents anemone stings, avoid predation from anemone and other fish.

35. FLOUNDER Lies on one side of its body - prevents shadow. Chromatophores modify color to match background. Throws sand on the top of their flattened body to increase concealment.

36. What do these BUTTERFLIES mimic?

37. Some INSECTS resemble twigs in physical structure and behavior. They can branch off a limb and remain motionless.

38. AUSTRALIAN TAWNY FROGMOUTH Resembles part of the tree in which it rests. This bird is active at night and remains motionless during dayight hours.

39. GRAY TREEFROGS occur as two different color morphs within the same population: a brown morph... . . . and a green morph.

40. EASTERN CORAL SNAKE is highly venomous Predators generally avoid snakes with a bright banding pattern of black, yellow, and red. ~ 70 spp. of New World snakes have this "coral" type of banding.

41. Warning signals need not always be visual. RATTLESNAKES possess a highly venomous bite and give a warning noise with their rattle.

42. Warning signals can be olfactory: SKUNKS- warning coloration and bad odor warn predators. Spray temporarily blinds close predators; offensive odor lingers long after discharge.

43. MONARCH BUTTERFLY feeds as larva on milkweed plants - contain toxins. Toxins are sequestered in tissues of adult. Distinctive colors of adult Monarch warns birds not to eat them.

44. VICEROY (left) closely resembles Monarchs. Although not distasteful, birds avoid Viceroy.

45. Katydids employ two types of defense. First, coloration resembles leaves - crypsis decreases chances of detection. If detected, second line of defense decreases probability of being captured - it hops away.

46. PEACOCK BUTTERFLY from Ireland has spots resembling eyes. These "eyes" frighten away insectivorous birds.

47. Squids deter predation by forming a group. Group formation may decrease per capita predation risk in number of ways: selfish herd behavior, confusion effects, or by having more individuals on look out for approaching predator. This may explain why large ungulates travel in herds.

48. ELK have keen sense of smell, good hearing, and are swift runners to avoid most predators. If trapped in deep snow, antlers are a match for most predators.

49. Turtles have tough integument which is virtually impenetrable. BOX TURTLES have broad hinge across plastron, allows them to completely close shell so tightly - not even a knifeblade can be inserted.

50. Six-lined Racerunner has a bright colored tail that distracts predators from its head. When caught, the tail breaks off allowing the lizard to escape = AUTOTOMY.