1. Ecology & Environmental Issues
We share the Earth…
Ecology & Environmental Issues

2. Everything is connected to everything else
Ecology
Putting it all together…
study of interactions between creatures & their environment, because…
Everything is connected to everything else

3. Ecology: the study of interactions that take place between organisms and their environment

4. Chapter 2: Principles of Ecology
You will describe ecology and the work of ecologists.
You will identify important aspects of an organism’s environment
You will trace the flow of energy and nutrients in the living and nonliving worlds.

5. 2.1: Organisms and their Environment
Section Objectives:
Distinguish between the biotic and abiotic factors in the environment
Compare the different levels of biological organization and living relationships important in ecology
Explain the difference between a niche and a habitat.

6. Biosphere the portion of Earth that supports living things.
Living things are affected by both the physical or nonliving environment and by other living things. How?

7. Abiotic and Biotic factors
Abiotic factors ~ The nonliving parts of an organism’s environment
Examples: air currents, temperature, moisture, light, and soil.
How does the abiotic factors determine which biotic factors live in an area?
biotic factors ~ All the living organisms that inhabit an environment
All organisms depend on others directly or indirectly for food, shelter, reproduction or protection

8. Levels of Organization
Organism~ An individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops
2. Population ~ a group of organisms, all of the same species, which interbreed and live in the same area at the same time; competition occurs

9. Levels of Organization II
3. Biological community ~made up of interacting populations in a certain area at a certain time.
~A change in one population in a community may cause changes in the other populations.
4. Ecosystem ~ Populations of plants and animals that interact with each other in a given area and with the abiotic components of that area.

10. Studying organisms in their environment
biosphere
ecosystem
community
population
organism

11. Organisms in Ecosystems
A habitat is the place where an organism lives out its life.
~ Habitats can change due to both natural and human causes
niche is the role or position a species has in its environment—how it meets its specific needs for food and shelter, how and where it survives, and where it reproduces in its environment.
~includes all its interactions with the biotic and abiotic parts of its habitat.
Why would two species fight or compete if they occupied one niche?

12. Symbiosis
The relationship in which there is a close and permanent association between organisms of different species
Three kinds of symbiosis are: mutualism, commensalism, and parasitism.

13. Symbiosis II 1.Mutualism ~ both species benefit
2. Commensalism ~one species benefits and the other species is neither harmed nor benefited.

14. Symbiosis III
3. Parasitism ~ a member of one species derives benefit at the expense of another species (the host) :usually harm but don’t kill host
Predators seek out and eat other organisms.
animals that predators eat are called prey.

15. 2.2: Nutrition and Energy Flow
Section Objectives
Compare how organisms satisfy their nutritional needs.
Trace the path of energy and matter in an ecosystem.

16. How organisms obtain energy
What is the ultimate source for the energy of life?
The sun.
The producers: Autotrophs~ An organism that uses light energy or energy stored in chemical compounds to make energy-rich compounds (Plants-photosynthesis

17. How organisms obtain energy II
The consumers: Heterotrophs ~ An organism that cannot make its own food and feeds on other organisms
depend on autotrophs for nutrients and energy.

18. Heterotrophs display a variety of feeding relationships.
Herbivore ~ feeds only on plants
Carnivores ~ kill and eat only other animals
Omnivores ~eat both plants & animals

19. Heterotrophs display a variety of feeding relationships. II
Scavengers eat animals that have already died
Decomposers break down the complex compounds of dead and decaying plants and animals into simpler molecules that can be more easily absorbed.

20. Food chains Feeding relationships
Level 4
Tertiary consumer
Sun
Top
carnivore
Feeding relationships
all food chains start with energy from the sun
first level of all food chains is plants
most food chains usually go up only 4 or 5 levels
all levels connect to decomposers
Level 3
Secondary consumer
Carnivore
Level 2
Primary consumer
Herbivore
Level 1
Producer
Fungi
Decomposers
Bacteria

21. Flow of Matter and Energy in Ecosystems
Food chains: the stepwise flow of energy and nutrients through an ecosystem.
from plants (producers)
to herbivores (primary consumers)
to carnivores (secondary and higher-level consumers
berries → mice → black bear

22. energy lost to daily living
Loss of energy
Loss of energy between levels of food chain
To where is the energy lost? The cost of living!
17%
growth
energy lost to daily living
only this energy moves on to the next level in the food chain
33%
cellular
respiration
50%
waste (feces)

23. Trophic levels represent links in the chain
Each organism in a food chain represents a feeding step, or trophic level, in the passage of energy and materials.

24. Food webs network of interconnecting food chains
It is a more realistic view of the trophic structure of an ecosystem than a food chain

25. Energy and trophic levels: Ecological pyramids
show how energy flows through an ecosystem.
illustrates that the amount of available energy decreases at each succeeding trophic level.
The total energy transfer from one trophic level to the next is only about ten percent because organisms fail to capture and eat all the food energy available at the trophic level below them.
Biomass is the total weight of living matter at each trophic level

27. Food chain pyramid Loss of energy between levels of food chain
can feed fewer animals in each level
Numbers 1
100
100,000
1,000,000,000

28. But what about nutrients?
Energy flows through but nutrients cycle
nutrients must be recycled to be available for the next generation
decomposers return nutrients to the soil after creatures die
fungi
bacteria
decomposers

29. Nutrients cycle around… through decomposers
consumers
decomposers
producers
phosphorus
potassium
iron
carbon
nitrogen
soil
magnesium
calcium

30. Energy flows Nutrients cycle
loss of energy
sun
secondary consumers
(carnivores)
decomposers
loss of energy
primary consumers
(herbivores)
loss of energy
producers (plants)
soil
soil

31. Ecosystem inputs nutrients cycle inputs energy nutrients biosphere
energy flows through
constant input of energy
nutrients cycle
Matter cannot
be created or destroyed
Don’t forget the laws of Physics!
nutrients can only cycle
inputs
energy
nutrients

32. 3.1: Communities: interacting populations in a certain area in a certain time
Section Objectives:
Identify some common limiting factors
Explain how limiting factors and ranges of tolerance affect distribution of organisms.
Sequence the stages of ecological succession.
Describe the conditions under which primary and secondary succession take place.

33. Common Limiting Factors
any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.
Factors that limit one population in a community may also have an indirect effect on another population. How????
Common Limiting Factors
Sunlight
Climate
Atmospheric gases
Temperature
Water
Nutrients/Food
Fire
Soil chemistry
Space
Other organisms

34. Ecological Succession
The natural progression of SPECIES and their EFFECTS on the environment
PIONEER Species – the first to invade a new environment (bare rock)
MODIFICATIONS by the first group leads to the second, the second the third, etc.
The CLIMAX species will end the succession.

35. Succession: Changes over Time
the orderly, natural changes and species replacements that take place in the communities of an ecosystem
Succession occurs in stages. At each stage, different species of plants and animals may be present
There are two types of succession—primary and secondary.

36. Primary succession
The colonization of barren land by communities of organisms
takes place on land where there are no living organisms
first species to take hold in an area like this are called pioneer species
An example of pioneer species is a lichen

37. What type of relationship?

38. Primary succession II
Decaying lichens, along with bits of sediment in cracks and crevices of rock, make up the first stage of soil development.
New soil makes it possible for small weedy plants, small ferns, fungi, and insects to become established.
Pioneer species
Moss
Lichen
Primary succession
Exposed rock

39. Primary succession III
After some time, primary succession slows down and the community becomes fairly stable, or reaches equilibrium.
A stable, mature community that undergoes little or no change in species is a climax community.
Climax community
succession

40. Forest Succession

41. Secondary succession
occurs after a disturbance has removed the vegetation but left the soil intact
Grasses grow first, then trees and other organisms.
may take less time than primary succession to reach a climax community.

42. Lake Succession LAKE community Sedimentation due to EROSION
SWAMP community forms
Eventually a FOREST community may form