Ecology: study of interactions between organisms (biotic) &

their environment/surroundings (abiotic)

Can you list biotic & abiotic factors in a pond ecosystem?

Biosphere: portions of planet where life exists

(land, water, air, atm)

8km above to 11km below Earth’s surface

Interactions w/in biosphere produce web of independence between organisms & environment

species

Biome

Levels of

Organization

Autotrophs: producers capture sun’s energy & use inorganic compounds (H2O & CO2) chemical energy stored in food/sugars & produce O2 in Photosynthesis

* Photosynthesis removes CO2 & adds O2 to atm

Chemosynthesis: uses chemical energy in bonds carbs

Ex. sulfur bacteria

(volcanic vents, hot springs)

H2S + O2 sulfur cmpds w/ chemical energy that converts CO2 in sea H2O carbs

Sunlight main energy source for all life on Earth

Photo autotrophs capture sunlight energy food energy

In photosynthesis

< 1% of sun’s energy that reaches Earth

is used by living things

Heterotrophs: Can’t harness sun’s energy

Consumers Rely on other organisms for energy/food

Herbivores: Plant Eaters

Carnivores: Meat Eaters

Omnivores

Eat plants and animals!

Hamburger (from cow)

Lettuce (plant)

Roll (wheat- from plant)

Pickle (cucumber/plant)

Detritovores: Feed on plant/animal remains

(mites, earthworms, crabs, snails)

Decomposers: break ↓ organic matter Fx at any level

Ex. Bacteria & Fungi, Mushrooms, Molds, Yeasts

Scavengers:

Carnivores that feed on dead bodies

Feeding Relationships

Energy flows in 1 direction through ecosystem

Suninorganic cmpdsautotrophsconsumers/heterotrophsFood chain: energy stored by producers passes through ecosystem along food chain.

Arrows = flow of energy

Food Web: Network of complex interactions that link food chains

Food Web       

                                                 

Identify the:

1. Producers 

2. Primary Consumers 

3. Secondary Consumers 

4. Herbivores 

5. Carnivores

6. Omnivores

7. What elements are missing from this food web?

Activity

Construct a Food web using the following animals. This ecosystem represents a farm area.  The corn is the main source of food for many of the herbivores in the area.  You do not have to draw pictures, you can just use the animal names and draw arrows between them.  

SNAKE,  CORN , CATERPILLAR, DEER, CROW, MOUSE, COUGAR, SQUIRREL, MICROORGANISMS (decomposers)

Trophic Levels: Only 10% of available energy transferred

Some lost as heat energy

~1/2 of light energy captured stored in plants as food.

Rest used for growth & metabolic processes.

Why can’t there be LOTS of trophic levels?

5th trophic level

4th trophic level

3rd trophic level

2nd trophic level

1st trophic level

Ecological Pyramids: Diagrams that show relative amount of

energy/matter w/in each trophic level

Energy Pyramid: Limits # of Trophic Levels

Only 10% of energy availbale w/in trophic

level transferred to next level b/c organisms

use much of energy consumed for life

processes (CR, mvmt, growth, development)

Biomass Pyramid: Amount of living tissue w/in trophic level

Pyramid of Numbers: Based on # of organisms w/in each trophic level

Pyramid of NumbersShows the relativenumber of individualorganisms at eachtrophic level.

Biomass PyramidRepresents the amount ofliving organic matter at each trophic level. Typically, thegreatest biomass is at the base of the pyramid.

Energy PyramidShows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat.

Section 3-2

Ecological PyramidsEcological Pyramids