1. Anna Dornhaus Assistant Professor in the Ecology & Evolutionary Biology Department University of Arizona

2. How everything in nature is connected

3. “Ecology” is the study of how organisms interact with their environment Ecology What they eat Where & when they live Who eats them

4. Interacting with your environment Ecology

5. Interacting with your environment Ecology

6. Interacting with your environment Ecology

7. Interacting with your environment Ecology Food chain

8. Interacting with your environment Predator Prey

9. Food chain Interacting with your environment Predator Consumer Producer

10. Food chain Every food chain starts with a producer Trophic level: high trophic levels are far from producers Interacting with your environment Predator Consumer Producer

11. How does the producer produce? Cycles of matter Predator Consumer Producer ?

12. How does the producer produce? Cycles of matter Producers: plants, algae, and some bacteria The process of creating organic matter (sugars, proteins, etc.) from inorganic matter (salts, water, air) in plants is called photosynthesis.

13. Making plants Cycles of matter Light is the energy that drives this process Carbon dioxide (or CO 2 ) from the air and water from the soil are used to make sugars Oxygen is a waste product

14. Cycles of matter Predator Consumer Producer CO 2 + water Producers make organic material; others just process it

15. Who eats the predator? Cycles of matter Predator Consumer Producer CO 2 + water ?

16. Cycles of matter Predator Consumer Producer CO 2 + water Decomposer

17. Cycles of matter Predator Consumer Producer CO 2 + water Decomposer

18. Cycles of matter Predator Consumer Producer CO 2 + water Decomposer 10%

19. Cycles of matter Predator Producer 10% 1% This means that predators ultimately only use 1% of the original plant-produced biomass.  To feed people meat, you need 10x more plants (area) than to feed people grains

20. Food chain Interacting with your environment Predator Prey

21. Interacting with your environment

22. Food web

23. Ecological networks Seed dispersers Plants Interacting with your environment … but in reality with thousands of species and many more interactions

24. Interactions Organisms also interact in other ways than eating or being eaten. For example: Other interactions Competition for food or nesting sites Parasitism Mutualism: – Pollination – Seed dispersal – etc.

25. Interactions Pollination What is pollination?

26. Interactions Pollination What is pollination? Plants having sex without moving! Pollinators collecting food

27. Interactions Pollination What is pollination? Plants having sex without moving! Pollinators collecting food  Plants offer nectar to attract animals (bees, bats, moths, other insects); in collecting nectar, these animals get pollen stuck on them, which is transported to the next plant

28. Interactions Pollination

29. Interactions Pollination Why do plants produce colorful, nice-smelling flowers?

30. Interactions Pollination Why do plants produce colorful, nice-smelling flowers? To attract pollinators! (and thus get their sperm=pollen spread to other plants!)

31. Interactions Seed dispersal Why do plants produce colorful, sugary fruits?

32. Interactions Seed dispersal Why do plants produce colorful, sugary fruits? To attract seed- dispersers! (often birds)

33. Interactions Plants need animals! Many plants cannot survive unless the right pollinators and the right seed disperser are present.

34. Interactions Protection: Ants and barrel cacti Cactus offers nectar, ants protect cactus by killing caterpillars and other herbivores

35. Interactions Protection: Ants and acacias Bullhorn acacia tree, Pseudomyrmex ant

36. Interactions Mutualisms Mutualistic interaction between different species evolved many times and is widespread. Humans and livestock Humans and gut bacteria Mushrooms and trees Orchids and fungus Mitos and chloroplasts in cells Ants and plants with extrafloral nectaries (e.g. barrel cacti) Ants and aphids Leaf-cutting ants and fungus Clownfish and sea anemones Corals and zooxanthellae

37. Interactions Close association of individuals of different species: Usually involves exchange of chemicals that one of the partners cannot make alone. Symbioses Lichens – a symbiosis of a fungus and a bacterium

38. The abiotic environment Why are most cacti only found in the American deserts?

39. The abiotic environment Why does any organism live where it lives? Usually three kinds of explanations: Abiotic environment (the right climate, nesting sites, etc.) Biotic interactions (prey is there) History (it evolved there and did not migrate somewhere else)

40. The abiotic environment Why are most cacti only found in the American deserts? Abiotic environment (dry with periodic rain; not too cold) Biotic interactions (can defend themselves against desert herbivores and compete with other desert plants) History (evolved in the Americas, and cannot migrate to Africa, for example)

41. Organisms interact with their biotic and abiotic environment Each animal & plant is part of a food web has a ‘trophic level’ (producer or consumer) interacts with other organisms in other ways (parasitism, competition, mutualisms) requires a certain abiotic environment (climate etc. – more on this later) Producers can make organic matter from inorganic; all others have to eat organic matter Summary: ecology

42. PBS Evolution series: The evolutionary arms race: chapter 7 "Symbiosis and leafcutter ants" (12 minutes)