1. Chapter 2 – Introduction to Ecology
Section 1: Organisms and Their Relationships

2. Ecology
Ecology
the study of the interactions between organisms and the biotic and abiotic components of their environment

3. The Biosphere
The biosphere is the portion of Earth that supports life.
“bio” means life
“sphere” refers to the shape of our planet that resembles a ball
“The ball of life”
Includes our atmosphere, landmasses, bodies of freshwater and saltwater, and locations below the Earth’s surface that supports life.

4. The Biosphere Cont. Biotic Factors Abiotic Factors
All of the LIVING things in an organism’s environment.
Abiotic Factors
All of the NONLIVING things in an organism’s environment
Includes temperature, air currents, sunlight, rainfall, soil type and available nutrients

5. A Key Theme in Ecology No single organism is isolated!!
The interconnectedness or interdependence of all organisms is central to the study of ecology
The survival of organisms depends on their interactions with their surrounding environment
Ex: Humans cannot live without the plants that produce food and oxygen

6. Levels of Organization

7. The Biosphere
Biosphere: the broadest and most inclusive level of organization
The Earth and its atmosphere make up our biosphere
Extends from 8 to 10 km (5-6 miles) above the Earth’s surface to the deepest parts of the ocean

8. Ecosystems
The biosphere is comprised of smaller units called ecosystems
Includes all of the organisms and the abiotic environment found in a specific place
Ex: Pond Ecosystem
Abiotic components: water temperature, amount of dissolved oxygen and carbon dioxide, the pH level
Biotic components: insects, fish, algae, aquatic plants, turtles
Some ecosystems can be considered the habitat of an organism.

9. Chapter 18
Ecosystem

10. The Niche Niche the role an organism plays in its environment
Includes:
Range of conditions the organism can tolerate
Methods by which it obtains resources
Interactions with its environment such as reproduction

11. Earthworms Niche

12. Community Interactions
all of the interacting organisms living in an area
Ex: All of the fish, turtles, insects, plants and algae make up the community of a pond
Competition occurs when more than one organism uses a resource at the same time.
Ex: Lions and hyenas compete for the same food sources.
Predation is the act of one organism consuming another for food.

13. Chapter 18
Community

14. Symbiotic Relationships
Most species survive because of relationships called symbiosis
Mutualism:
Both organisms benefit
Ex: The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos

15. Symbiotic Relationships
Commensalism:
One benefits; the other is not affected
Ex: Sea anemone and the clown fish.
Parasitism:
One benefits at the expense of the other
Ex: Deer tick and mammal

16. Visual Concept

17. Chapter 2 – Principles of Ecology
Section 2: Flow of Energy in an Ecosystem

18. Energy in an Ecosystem Autotrophs: primary producers
make their own food
Use energy from sunlight or inorganic substances
Foundation of all ecosystems
they make energy available for all of the other organisms
Ex: Plants

19. Energy in an Ecosystem Heterotrophs:
get energy by consuming other organisms
Called “consumers”
Herbivores
eat only plants
Carnivores
eat others

20. Energy in Ecosystems Heterotrophs Cont: Omnivores Detrivores
eat both plants and animals
Detrivores
eat dead/decaying material
Decomposers are similar to detrivores
Break down dead organisms by releasing digestive enzymes (fungi)
Important because they make nutrients available for all other organisms

21. Models of Energy Flow
Ecologists use food chains and food webs to show energy flow in ecosystems
Trophic level
Each step in a food chain or food web
Autotrophs are the first trophic level in ALL food chains and food webs!

22. Important Terms for Food Chains and Food Webs
Primary producers: make their own food
Primary consumers: eat the primary producers
Secondary consumers: eat the primary consumers
Third-level consumers: eat the secondary consumers

23. Food Chains
Food chains: a simple model that shows how energy flows through an ecosystem
Arrows show one-way energy flow
Each organism uses some of the energy from the organism it eats
The remaining energy is lost to the surrounding environment

24. Food Webs
Food webs: models that represent the interconnected food chains in which energy flows through a group of organisms

25. Ecological Pyramids
Diagrams that show the relative amounts of energy, biomass or numbers of organisms at each trophic level
Biomass is the total mass of living matter at each trophic level
Approximately 90% of all energy at a tropic level is NOT transferred to the level above it

26. The Biogeochemical Cycles

27. Cycles of the Biosphere
Energy is not recycled in a ecosystem
Matter (biomass) is recycled in a ecosystem
Nutrient: a chemical substance that an organism needs from its environment.
Nutrient cycling involves both the biotic and abiotic portions of an ecosystem.
These are called the biogeochemical cycles.

28. The Water Cycle: more of a physical process than a chemical one.

29. The Water Cycle Key Terms:
Evaporation: water returning to the atmosphere from oceans, lakes, and rivers
Transpiration: water returning to the atmosphere from the surface of plants
Precipitation: water returning to the earth from the atmosphere
Percolation: water running through the soil
Runoff: water running on the surface of the earth.

30. The Carbon Cycle
Two natural processes help to cycle carbon through the ecosystem.
Photosynthesis:
autotrophs
take in CO2 and produce organic compounds
Make them available then for consumers.
Cellular Respiration;
both autotrophs and heterotrophs
convert energy rich organic compounds into ATP
powers cellular functions.

31. The Carbon Cycle Deposition Carbonate in sediments: dead materials:
converted to peat, coal, oil or gas deposits (carbon stored as fossil fuel)
carbon is released when fossil fuels are burned
Carbonate in sediments:
shells, coral, algae fall to bottom of ocean creating limestone rock.
Carbon is released in the form of bicarbonates

32. The Carbon Cycle

33. There are none! Brain Break
Try to count the number of black dots on the image below...
There are none!

34. The Nitrogen Cycle
Nitrogen enters ecosystems through two natural pathways.
Nitrogen fixation, where certain bacteria convert N2 to minerals that can eventually be used by plants to produce nitrogenous organic compounds.

35. The Nitrogen Cycle
Chemical nitrogen fixation - lighting bolts change nitrogen gas to nitrates or nitrogen is added to the soil by chemical fertilization.
Some bacteria break down detritus and animal waste producing ammonium through Ammonification
Certain bacteria convert ammonium into nitrate, a process called Nitrification.
Nitrate can be used by plants.

36. The Nitrogen Cycle
Some bacteria take oxygen from the nitrate and release N2 back into the atmosphere called Denitrification.

37. WHAT IS PRODUCED (Products)
PROCESS
By What Organism
Compounds Used
WHAT IS PRODUCED (Products)
NITROGEN FIXATION
Nitrogen fixing bacteria in soil and in legume roots.
Nitrogen Gas (N2)
Usable nitrogen:
Nitrates (NO3-) made in roots of legumes and Ammonium (NH4+) and in the soil.
AMMONIFICATION
Decomposers (Bacteria and Fungus)
Detritus and waste
Ammonia
NITRIFICATION
Nitrifying Bacteria
Ammonium
Nitrites (NO2-) & NO3-
ASSIMILATION
Chemical reactions in the organism.
Nitrates
Any nitrogen based compound needed by plants and animals. Nitrogen is used to make amino acids.
DENITRIFICATION
Denitrifying Bacteria
Excess nitrates
Nitrogen Gas

39. Phosphorus cycle

40. Phosphorus cycle Needed for growth and development
Short term- cycled from soil to producers and producers to consumers
Long term- Phosphorus comes from weathering and erosion of rocks

41. Rates of nutrient cycling
Decomposition rates largely determine the rates of nutrient cycling
The rate at which nutrients cycle in an ecosystem depends on the rate of decomposition.
Decomposition can take up to 50 years in the tundra, while in the tropical forest, it occurs much faster.
Quantities of nutrients in the soil of different ecosystems also varies, depending on the rate of absorption by the plants.

42. Nutrient cycling is strongly regulated by vegetation
In a terrestrial ecosystem most of the mineral nutrients cycle within the ecosystem.
In addition to the natural ways, nitrogen- containing fertilizer contributes to the total amount of nitrogen materials in ecosystems.

43. The End see it wasn’t that bad 