1. Unit 7 Ecology

2. Ecology What do you mean by environment?
the study of interactions between organisms and their environments
What do you mean by environment?
The environment is made up of two factors:
Biotic factors- all living organisms inhabiting the Earth
Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)
What do you think about when I say ecology? Recycling? Acid rain?

3. Biosphere Ecosystem Community Population Organism
Just like with classification, ecology is hierarchal. Each level builds on itself and they fit together like nesting boxes.
Population
Organism

4. The lowest level of organization
Organism
any unicellular or multicellular form exhibiting all of the characteristics of life, an individual.
The lowest level of organization
The lowest level is the individual. The organism. Here we see a salmon and a bear as examples of organisms. REMINDER: organisms die, species go extint

5. Population
a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources ( food, Water, mates, shelter)
The next level is a population. A population consists of a single species living together and breeding. Give me an example of a population. Ex. large mouth bass living in Lake Meade. Beetles living under the same log. Here we have salmon spwning and two bears fishing.

6. Community
several interacting populations that inhabit a common environment and are interdependent.
Next level is a community which is several populations living together and depending on each other. What does interdependent mean? An example of a community is shown here with the bear and the salmon. They both live in a common environment and the bear needs the fish for food? How does the salmon need the bear?

7. Ecosystem
populations in a community and the abiotic factors with which they interact
ex. marine, terrestrial

8. The highest level of organization
Biosphere
life supporting portions of Earth composed of air, land, fresh water, and salt water.
The highest level of organization
The Biospher is composed of many Biomes
Lets review. Organisms make up populations, populations make up communities, communities and abiotic factors make up ecosystems, and all of the ecosystems make up the biosphere. From one to many and each depending on the other.

9. Land Biomes
Biome- geographic areas that have similar climates and ecosystems
The 6 most common biomes are:
Tundra
Taiga
Temperate Deciduous Forest
Tropical Rain Forest
Grassland
Desert

10. Habitat vs. Niche
Habitat- the place in which an organism lives out its life (address)
Niche - the role a species plays in a community (job)
A niche is determined by a limiting factor.
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
Examples of limiting factors-
Amount of water, food, Temperature
“The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism's ‘address’, and the niche is its ‘profession’, biologically speaking.”
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

11. Feeding Relationships
There are 3 main types of feeding relationships
Producer- Consumer
Predator- Prey
Parasite- Host
Producer- all autotrophs (plants), they trap energy from the sun to make food (sugar).
Bottom of the food chain
How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?

12. Consumers- all heterotrophs: they ingest food containing the sun’s energy
Herbivores
Carnivores / Scavangers
Omnivores
Decomposers
Eat plants
Primary consumers
Prey animals
Energy moves up the food chain through the producer/consumer relationship.

13. Carnivores Scavengers Omnivores Feed on carrion, dead animals
eat meat
Predators
Hunt prey animals for food.
Scavengers
Feed on carrion, dead animals
Omnivores
eat both plants and animals
Decomposers
Breakdown the complex compounds of dead and decaying plants and animals
Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders

14. Symbiotic Relationships Symbiosis- two species living together
3 Types of symbiosis:
Commensalism
Parasitism
Mutualism
Cleaning shrimp

15. Trophic Levels Food chain
Each link in a food chain is known as a trophic level.
Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem.
Food chain
simple model that shows how matter and energy move through an ecosystem

16. E N R G Y Trophic Levels Producers- Autotrophs
Tertiary consumers- top carnivores
Secondary consumers-small carnivores
Primary consumers- Herbivores
Producers- Autotrophs

18. Food web
shows all possible feeding relationships in a community at each trophic level
Represents a network of interconnected food chains
Food chain Food web
(just 1 path of energy) (all possible energy paths)

20. Three Key Features of Populations Size Density Dispersion
Population Dynamics
Three Key Features of Populations
Size
Density
Dispersion
Clumped
Even/Uniform
random
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

21. Size: number of individuals in an area
Growth Rate: How many individuals are born vs. how many die
Birth Rate (natality) - Death Rate (mortality) = rate of natural increase
POST-REPRODUCTIVE
REPRODUCTIVE
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
PRE-REPRODUCTIVE

22. Density: measurement of population per unit area or unit volume
Pop. Density = # of individuals ÷ unit of space
4 Factors that affect density
Immigration- movement of individuals into a population
Emigration- movement of individuals out of a population
Density-dependent factors- Biotic factors in the environment that have an increasing effect as population size increases
Ex. Disease, competition
Density-independent factors- Abiotic factors in the environment that affect populations.
Ex. temperature, storms, habitat destruction, drought
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

24. Factors That Affect Future Population Growth
Immigration + + -
Population
Mortality
Birth -
Emigration

25. Other factors that affect population growth
Limiting factor
any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
Amount of water, food, temperature, predation
Few organisms present
None
Few organisms present
None
Many organisms present
Limiting Factor- Zone of Tolerance

26. Carrying Capacity
the maximum population size that can be supported by the available resources
There can only be as many organisms as the environmental resources can support
S-shaped curve (logistic growth) N u m b e r
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
Carrying Capacity (k)
J-shaped curve (exponential growth)
Time

27. Nutrient Cycles
Cycling maintains homeostasis (balance) in the environment.
3 cycles to investigate:
Water cycle
Carbon cycle
Nitrogen cycle

28. Water cycle –
Evaporation, transpiration, condensation,precipitation

29. Carbon cycle -
Photosynthesis and respiration cycle carbon and oxygen through the environment.

30. Nitrogen cycle - Atmospheric nitrogen (N2) makes up nearly 80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into usable forms.
Nitrogen fixation-convert atmospheric nitrogen (N2) into ammonium (NH4+) which can be used