1. Terrestrial Ecology Ecology Energy Flow Ecosystem Structure
Interactions Among Species
Population Dynamics
Reproductive Patterns

2. Ecology Ecology is a study of connections in nature.
How organisms interact with one another and with their nonliving environment.
Figure 3-2

3. Ecology
Ecosystem- A community of different species interacting together & with the chemical & physical factors making up its non-living environment.
Species- groups of organisms that can mate and produce fertile offspring (5 to 100 million on earth).
Population- A group of individual organisms of the same species living w/in a particular area.
Communities- The population of all species living & interacting in an area.
Habitat- The place where an organism or a population lives.
Niche- The total way of life or role of a species in an ecosystem.
All the physical, chemical, and biological conditions a species needs to live & reproduce in an ecosystem.

4. Ecology
Organisms, the different forms of life on earth, can be classified into different species based on certain characteristics.
Figure 3-3

5. Energy Flow
Ecosystems consist of nonliving (abiotic) and living (biotic) components that interact together
Figure 3-10

6. Energy Flow
Abiotic – nonliving parts of ecosystems (water, air, nutrients, solar energy)
1. Range of Tolerance – range of physical and chemical environments in which a species can survive.
 Law of Tolerance: the abundance or distribution of an organism can be controlled by certain factors
Tolerance Limits: The upper and lower limits to the range of particular environmental factors within which an organism can survive.
Organisms with a wide range of tolerance are usually distributed widely, while those with a narrow range have a more restricted distribution.

7. Lower limit of tolerance Upper limit of toleranceNo
organisms
Few
organisms
Few
organisms No
organisms
Abundance of organisms
Population size
Figure 3.11
Natural capital: range of tolerance for a population of organisms, such as fish, to an abiotic environmental factor—in this case, temperature. These restrictions keep particular species from taking over an ecosystem by keeping their population size in check.
Zone of
intolerance
Zone of
physiological stress
Optimum range
Zone of
physiological stress
Zone of
intolerance
Low
Temperature
High
Fig. 3-11, p. 58

8. Energy Flow
2. Limiting Factor – abiotic factors that can limit or prevent the growth of a population.
Limiting Factor Principle – too much or too little of any abiotic factor can limit or prevent the growth of a population.
  Ex. Desert plants (water)
Ex. Aquatic Ecosystems (temp, light, dissolved oxygen, nutrient availability, salinity)

9. Energy Flow
Biotic – living parts of ecosystems (plants, animals, and microorganisms) biota.
1.Producers or Autotrophs (photosynthesis and chemosynthesis)
Plants
Some protists
2.Consumers or Heterotrophs
a.      Herbivores
b.      Carnivores
(secondary or tertiary consumers)
c.      Omnivores
d.      Scavengers
e.      Detritivores
f.       Detritus feeders
g Decomposers

10. Energy Flow 3.Important Biotic Processes
Cellular Respiration – removes oxygen from the environment and adds carbon dioxide and water.
Anaerobic Respiration – can add methane gas, ethyl alcohol, acetic acid, and hydrogen sulfide to the environment.
Photosynthesis– removes carbon dioxide and water from the environment and adds oxygen and water.

11. Energy Flow Producers-
An organism that uses solar energy (green plant and some protists like algae) or chemical energy (some bacteria) to manufacture its food.
First Trophic Level
Basic source of all food but all energy comes from the sun
Most producers capture sunlight to produce carbohydrates by photosynthesis:
                                  

12. Energy Flow
Biomass
Biomass is dry weight of organic matter produced by plants & represents the chemical energy stored at each energy level.
Stems, roots and leaves
Can be used as electrical energy from wood, garbage & agricultural waste.

13. Primary Productivity of Ecosystems
Energy Flow
Primary Productivity of Ecosystems
Productivity–the rate at which plants convert solar energy to biomass (NPP)
Primary production- The conversion of solar energy to the energy of chemicals bonds during photosynthesis by autotrophs
Secondary production- The total biomass that heterotrophs generate by consuming autotrophs
Gross Primary Productivity- the energy that results when autotrophs
convert solar energy to chemical energy
High GPP-
Shallow waters near continents
Coral reefs
Forests
Low GPP
Deserts
Polar regions
Open ocean

14. Energy Flow
Net Primary Productivity- what is left of GPP after it is used by an ecosystems producers to stay alive, grow and reproduce.
- This is the energy or biomass available to consumers in an ecosystem.
High NPP
Estuaries
Swamps and marshes
Tropical rain forests
Low NPP
Open ocean
Tundra
Desert
The earth’s net primary productivity is the upper limit determining the planet’s carrying capacity for all consumer species.
Our Share of Earth’s NPP
1)      We use, waste or destroy about 27% of earth’s NPP
2)      We use, waste or destroy about 40% of the NPP of terrestrial ecosystems

15. Energy Flow Net Primary Productivity Gross Primary Productivity
GPP = NPP + Respiration
Net Primary Productivity
Respiration
Gross Primary Productivity
99% of solar energy is reflected or passes through producers w/o being absorbed
1% of solar energy striking producers in captured by photosynthesis (GPP)
40% of GPP supports the growth and reproduction of producers (NPP)

16. Energy Flow
Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains.
Primary Consumers
Second Trophic Level
Herbivores- eat producers
Omnivores- feed on both plant and animals.
Secondary Consumers
Third Trophic Level
Carnivores- Primary consumers that eat other primary consumers
Tertiary Consumers
Fourth Trophic Level
Carnivores that eat carnivores.

17. (decomposers and detritus feeders)
First Trophic
Level
Second Trophic
Level
Third Trophic
Level
Fourth Trophic
Level
Producers
(plants)
Primary consumers
(herbivores)
Secondary consumers
(carnivores)
Tertiary consumers
(top carnivores)
Heat
Heat
Heat
Solar energy
Heat
Heat
Figure 3.17
Natural capital: a food chain. The arrows show how chemical energy in food flows through various trophic levels in energy transfers; most of the energy is degraded to heat, in accordance with the second law of thermodynamics.
Heat
Heat
Detritivores
(decomposers and detritus feeders)
Heat
Fig. 3-17, p. 64

18. Energy Flow Scavengers- consume dead animals
Detritivores- Specializes in breaking down dead tissues and products into smaller particles- insects
Decomposers- Fungi and Bacteria that digests parts of dead organisms, cast-off fragments, and wastes of living organisms and recycles those nutrients back into the environment
Detritus feeders- eat off of partially decomposing materials such as leaf liter, animal dung or plat debris

20. Energy Flow Decomposition
As plant or animal matter dies it will break down and return the chemicals back to the soil.
This happens very quickly in tropical rainforest which results in low-nutrient soils.
Grasslands have the deepest and most nutrient rich of all soils

21. Energy Flow
Ecological efficiency: percentage of useable energy transferred as biomass from one trophic level to the next.
Figure 3-19

22. Energy Flow
10% Rule
We assume that 90% of the energy at each energy level is lost because the organism uses the energy. (heat)
It is more efficient to eat lower on the energy pyramid. You get more out of it!
This is why top predators are few in number & vulnerable to extinction.

23. Energy Flow
Shows the decrease in usable energy available at each succeeding trophic level in a food chain or web.

24. Energy Flow
Food Chains- determines how energy & nutrients move from one organism to another through the ecosystem
Arrows – point from the producer to the consumer

25. Energy Flow
Food Webs- Interconnected food chains that shows all possible energy transfers within an ecosystem