1. Ecology 1: Ecosystems

2. Levels of Organization
Organism
Ex. an elephant
Population
A group of individuals in the same species, living and interacting in one area
Ex. a herd of elephants in the Serengeti
Community
Multiple populations interacting in one area
Ex. grazing antelope, elephants and giraffes in the Serengeti
Ecosystem
All populations in one area interacting with each other and their non-living environment.
Ex. the Serengeti (all organisms plus climate, nutrients, etc.)

3. Levels of Organization
Biosphere
All areas of the earth from the ocean depths to the atmosphere that support life.

4. Ecological roles Autotrophs - Producer Heterotrophs - Consumer
makes own food (through photosynthesis or chemosynthesis)
Heterotrophs - Consumer
must eat other organisms for food
primary (mouse), secondary (fox), tertiary (bobcat)
Herbivore (eats plants)
Carnivore (eats meat)
Omnivore (eats both or “all”)

5. Other types of Heterotrophs
Detritivore
Organisms that feed on animals remains and dead material (crabs, earthworms)
Decomposer
An organism (ex. fungi or bacteria) that completes the final breakdown of materials in an ecosystem

6. How does energy enter the ecosystem?
Energy hits the earth in the form of sunlight
Autotrophs convert sunlight energy into organic molecules
Less than 1% of the sun’s energy is converted into organic material
Eventually all energy is lost back to the atmosphere as heat.
Picture we can add here???

7. How does energy move through an ecosystem?
Energy trapped in autotrophs (producers) then gets transferred to heterotrophs (consumers) as one organism eats another
The easiest way to show this is by using a food chain, food web, or food pyramid.
Food chain – series of steps in which organisms transfer energy by eating and being eaten.

8. Food Web
Links all ecosystems in a food chain together

9. Food Pyramids
A food pyramid is designed to show the organisms in an ecosystem, grouped by their feeding position or trophic level (1st=prod, 2nd=herbivores, etc)
Both food chains and food pyramids show that only 10% of the energy at one trophic level makes it to the next trophic level (from the 2nd law of thermodynamics).
Think we need more explanation why here than just 2nd law!
Expose the right side of the picture to help explain??

10. Primary Productivity
The rate at which new organic material is created in an ecosystem by producers is called the Primary Productivity
The more energy entering the food chain (from producers), the more that can pass up through the levels (only 10% moves up at each level), and as result, the more levels there can be.
Therefore, the ecosystems with the most productive producers have the most levels (ex. rain forest)
In most cases, there are only 3-4 levels.
End of 3.2
Don’t forget I have the Presentation Pro for diagrams now. I just copied it and looked at it briefly so I am not sure if all diagrams are there or not!

11. How do nutrients cycle? Biogeochemical cycles Water Carbon and Oxygen
Energy follows a ONE-WAY path
Sun living organisms heat atmosphere
Matter CYCLES through living organisms endlessly
Biogeochemical cycles
Water
Carbon and Oxygen
Nitrogen

12. Water Cycle
How much detail are we expecting in each of these cycles?

13. Carbon and Oxygen Cycle

14. Nitrogen Cycle

15. Niches Niches vs Habitats
A habitat is the location where a species lives.
Ex. tall grassland/prairie
A niche includes all of the species’ requirements plus its role in the ecosystem. It is determined by all the the abiotic and biotic factors relevant to the species.
Ex. Top predator in prairie areas where gophers live, and the temperature is never below freezing.
What never freezes – gopher, predator, prairie???

16. Niche differences Organisms can be identified as either Generalists
Organisms with a broad niche
Eat lots of types of food
Live in many types of environments
Ex. house mice
Specialists
Organisms with a narrow niche
Eat a narrow range of food items
Live in few, specific types of habitats
Ex. panda bear
Also not in the book, but I think it’s valuable
Agreed. Will we ever do k and r?

17. Mutualism Mutualism occurs when both species benefit
Rhinos and oxpeckers
trees and mycorrhizae,
ants and acacia
Termites and protist
Pollination (Yucca and yucca moth)

18. Parasitism one organism feeds on/lives on another species
typically host is bigger than parasite
parasites usually do not kill host (weaken them)
parasites need host for food, shelter, etc.
ex. fleas on dog, tapeworm in human, mistletoe, lamprey

19. Commensalism
Commensalism occurs when one species benefits, and the other neither benefits, or is harmed
examples:
clownfish and anemones
epiphytes and trees
Cattle egrets and ungulates

20. Predation Predation - one organism feeds upon the other
predator usually bigger than prey
ex. lion eating zebra
Remove second part?
Probably.

21. Prey Strategies

22. Competition
When two species use the same resources, they are said to compete and their interaction = competition.
ex. lions and hyenas compete for food in Africa
Competition does not necessarily involve contact; interaction may be only by means of effects on the resources.
No two organisms can occupy exactly the same niche at the same time

23. What determines where species can live?
All species have requirements for many factors/conditions.
Abiotic factors – non-living factors; ex. temperature, precipitation, pH
Biotic factors – other species; ex. prey species, competing species
For each of these factors, species exhibit a range of tolerance.
For example, a fish species may only be found within a pH range of 4.5 to 6 in lakes.
“Preferences”????? Is there a better term?

24. Biomes
A particular type of biotic and abiotic factors (esp. climate) that create a similar ecosystem but are found in different areas of the world.
The world’s terrestrial (land) biomes are: rain forest, deciduous (temperate) forest, coniferous forest (taiga), desert, grasslands (savanna/prairie), and tundra.

25. Biome distribution
Should we have them do this section on their own with the worksheets from last year?

26. Water Biomes Two Key abiotic factors 1. Fresh water or Salt water
2. Sunlight
or no sunlight

27. Freshwater Habitats
These habitats are distinct from both marine and terrestrial habitats and are very limited in area.
make up about 2% of earth’s surface
can be divided into
Flowing water (rivers) standing water (ponds and lakes) and wetlands (seasonal coverage)

28. Freshwater Habitats Estuaries These are very important for
Breeding grounds for fish
Filtering water
Very productive ecosystems!
Disappearing fast (flat land near the ocean)

29. Ocean 75% of earth’s surface
Continental shelf - shallow ocean waters - smallest area; large number of species (kelp forests)
Intertidal zones
Along our coast
Species can tolerate being in and out of water
Sea stars, algae, sea anemones
Coral Reefs
The “rain forests” of the ocean
High diversity
In tropical waters

30. Ocean
open sea surface - contains plankton (free-floating microscopic organisms), bacteria, algae, fish larvae; responsible for 40% of world’s photosynthesis
Benthic zone - deep sea waters - below 1000’ feet animals adapted to dark; some blind/bioluminescent

31. SUCCESSION
When a disturbance impacts an ecosystem, it recovers through a process known as succession.
Succession on newly formed habitat is called primary succession.
No remaining organisms or soil
Examples, lava flow, sand dune, glacier retreat
It can take years from sand dune to forest.