1. Ecology Chapter 3.1 to 3.3

2. What is Ecology?
Ecology – the study of interactions among organisms and between organisms and their environment
Biosphere – the largest of the areas of the earth containing the portion of the planet that life exists, including land, water and air (atmosphere)

3. Levels of Organization
Ranges in complexity from single individual to entire biosphere.

4. Levels of Organization
Individual – one organism
Population – group of individuals that belong to the same species and live in the same area
Species - a group of individuals so similar to one another that they can breed and produce fertile offspring.
Community –different populations that live together is a defined area
Ecosystem – all the organisms that live in a similar area along with the nonliving material
Biome – group of ecosystems (similar climate)
Biosphere – entire earth

5. Ecological Methods
Scientists use 3 basic methods to conduct ecological research.
1. Observing – qualitative and quantitative observations
2. Experimenting – used to test hypotheses, can set up artificial environments and manipulate conditions
3. Modeling – models are made to study events that have occurred over large time periods, or are large in scale

6. Interactions Among Organisms- Energy Flow
Sunlight is the main energy source for life on Earth
Producers – autotrophs (make their own energy using the sun)
Photosynthesis – using light to produce energy / food
Chemosynthesis – using inorganic molecules to produce energy / food

7. Energy Flow
Photosynthesis
Chemosynthesis

8. Energy Flow Consumers – heterotrophs (cannot make their own energy)
Herbivores – consume plants
Carnivores - consume meat
Omnivores – consume both
Detritivores –feed on dead or decaying matter
earthworms, mites, crabs, snails
Decomposers – break down organic matter
bacteria & fungus

9. Energy Transfer / Feeding Relationships
Energy flows in one direction
Food Chain- series of steps where energy is transferred by eating and being eaten
Trophic Levels – each step in a food chain
Food Web –links all food chains in ecosystem together

10. Food Chain vs. Food Web

11. Ecological Pyramids
Diagram that shows relative amounts of energy or matter contained within each trophic level in a food chain or food web for an ecosystem
Energy Pyramid – energy available at each trophic level
- 10% rule
2. Biomass Pyramid – amount of living tissue/potential food available in each level
3. Pyramid of Numbers - number of individual organisms

12. Examples of Pyramids

13. Recycling in the Biosphere
Water Cycle
Evaporation, precipitation, condensation, transpiration, run-off, ground water
Video
Song

14. Nutrient Cycle Carbon Cycle – carbon fixation, CO2
Photosynthesis, respiration
Fossil fuels
Human Activities
Mining, cutting forests, burning fossil fuels
Video

15. Biogeochemical Cycles
Nitrogen cycle – nitrogen fixation (bacteria), denitrification
Video

16. Biogeochemical Cycles
Phosphorus Cycle
Does not enter atmosphere.
In land, rocks, soil and ocean sediment as inorganic phosphate.
Will dissolve in water.
Video

17. Nutrient Limitation
Primary Productivity – rate of production of organic matter by producers
Amount of available nutrients.
Limiting Nutrients – nutrient that limits productivity when scarce.
Aquatic ecosystems – large input of limiting nutrient can cause an increase of algae or producers = algal bloom

18. What shapes an ecosystem?
Chapter 4.2
What shapes an ecosystem?

19. Biotic Factors Biological influences on organisms within an ecosystem
Include all living organisms.
Cast of characters that an organism might interact with
Bullfrog:
Plants and algae as a tadpole
Herons that eat adult bullfrogs
Other species that compete with frog for space and food.

20. Abiotic Factors Physical or non-living factors that shape an ecosystem
Climate:
Temperature, precipitation, humidity.
Wind, nutrients availability, soil type, sunlight
Biotic and Abiotic factors together determine the survival and growth of an organism and productivity of an ecosystem

21. Niche
An organisms habitat is its address, its niche is its occupation.
Full range of physical and biological conditions in which it lives and the way the organism uses these conditions.
Type of food it eats, how it obtains food, what other species use the organism as food.

22. Community Interactions
Competition- when organisms of same or different species attempt to use an ecological resource in the same place and at the same time.
Resource- necessity of life
Competitive Exclusion Principal- No two species can occupy the same niche in the same habitat at the same time.
Losing organism will fail to survive.

23. Community Interactions
Predation- One organism captures and feeds on another organism.
Symbiosis- “living together”
Mutualism- both benefit
Flowers and insects
Commensalism- one benefits, other is neither helped nor harmed.
Barnacles on marine animals
Parasitism- one organism lives on or inside another and harms it.
Tapeworms, fleas, ticks, lice

24. Label each

25. Ecological Succession
Predictable changes that occur in a community over time.
Ecosystems are constantly changing in response to natural and human disturbances.
As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further change.

26. Ecological Succession
Primary Succession -occurs on surfaces where no soil exists
Volcanic eruptions, bare rock
Pioneer species- first species to populate
Often lichens (fungus and algae)
When they die they add organic material to become soil.
Secondary succession – a disturbance changes an existing community without removing soil.
Land clearing and farming
Wildfires

27. Chapter 5.1 to 5.2: Populations

28. Three important characteristics of a population
1. Geographic Distribution/Range
Area inhabited by a population
Varies in size- Microscopic to miles
2. Population Density
Number of individuals per unit area.
Can again vary greatly
3. Population Growth Rate
A. Number of Births
B. Number of Deaths
C. Number of individuals who have entered/leave population = immigration and emigration

29. Types of Population Growth
Exponential Growth-
Under ideal conditions with unlimited resources.
Will start out slow and then approaches an infinitely large size - J curve
Reproduce at a constant rate - Not in natural populations!
Logistic Growth
Populations growth will slow or stop after a period of exponential growth
As resources become less available, the growth of a population slows or stops - S curve
Reached carrying capacity- number of individuals that a given environment can support

31. Limits to Growth Limiting factors cause population growth to decrease.
Density Dependent- only become limiting when a population reaches a certain level (TOO LARGE)
Competition
Predation
Parasitism
Disease
Density Independent- affects populations in same way regardless of size
Unusual weather, natural disasters, seasonal cycles, human activities

32. Chapter 6.2 to 6.4: Humans in the Biosphere

33. Classifying Resources
Renewable resources- can regenerate or can be replenished by biochemical cycles
Can be living or nonliving
Nonrenewable resource- cannot be replenished by natural process.
Fossil fuels: coal, oil, natural gas.
Classification depends on context
EX: Trees
Single vs. entire population
Sustainable development
Using natural resources without depleting them.

34. Different types of Resources
Land Resources
Soil erosion- wearing away of soil by wind and water
Desertification-turning once productive areas into deserts.
Forest Resources
Deforestation- loss of forests
Fishery Resources
Overfishing
Aquaculture- raising aquatic animals for human consumption
Air Resources
Smog, pollutant
Freshwater Resources
Pollution

35. Biodiversity: Greatest Natural Resource
Sum total of all the genetically based variety of all organisms in the biosphere
Ecosystem Diversity
Habitats, communities, ecological processed
Species Diversity
Number of different species in the biosphere
Genetic Diversity
Sum total of all the genetic information carried by all organisms living on earth today.

36. Threats to Biodiversity
Extinction- species disappears
Endangered species- population size declining
1. Habitat Alteration
Habitat fragmentation- development splits ecosystems into pieces
2. Demand for wildlife products
3. Pollution
Biological Magnification- concentration of harmful substances increases at higher trophic levels
4. Introduced species
Invasive species- reproduce rapidly because of lack of predators
Conservation efforts are in place to manage natural resources.

37. Biological Magnification

38. Charting the course for the future
Researchers are gathering data to study the effects of human activities on the biosphere.
Ozone depletion.
Ozone layer kilometers above earth surface. Absorbs UV light before it reaches earths surface.
Global climate change
Global warming- increase in average temperature of biosphere.