Ecology

• Ecology is the scientific study of interactions among organisms and between organisms and their environment

Species population BiosphereEcosystem Biomecommunity

Levels of Organization

Species is a group of organisms so similar to one another they can breed and produce fertile offspring. Ex. homo sapiens (humans).

Population- Groups of individuals belonging to the same species that live in the same area. Ex. Elmwood park population

Levels of organization

• Community assemblages of different populations that live in the same area.

EX. the humans, birds, bees, squirrels, mice, mosquitoes, and bacteria that live in Elmwood Park.

Ecosystem is a collection of (biotic) organisms that live in a particular place, together with their non-living (a biotic) environment. Ex. aquatic life in the Passaic River.

• A biome is a collection of ecosystems that have the same climate and similar dominant communities.

Ex. the rain forestBiosphere- The Earth in which life

exists, land, water, and atmosphere.

Ecological Methods• Observing- Field biology gathering demographic

data.• Experimenting- Biologist may set up artificial

environments in a laboratory and manipulate conditions.

• Modeling-Many ecological phenomena occur over long periods of time. Biologist use mathematical formulas based on data collected. Ex. effects of global warming on ecosystems.

Check Point

1. List the six different levels of organization from smallest to largest?

2. Describe the three basic methods of ecological research.

3. describe two ways in which you interact with the land, water, and air- every day.

4. Suppose you wanted to know if water in a certain stream was safe to drink which ecological method would you employ and why?

Energy Flow

Producers- Make their own energy.1. Autotrophs- Obtain energy from the

sun. Ex. plants, algae, and bacteria

6CO2 + 6H2O C6H12O6 +6O2light

2. Chemotrophs - obtain energy from chemicals in a process known as chemosynthesis.

Ex. sulfur bacteria

Consumers

• Heterotrophs – consume other organisms for energy.

• Herbivores-Eat plants.• Carnivores- Eat meat.• Omnivores- Eat plants and animals. Ex.

humans• Detritivores- Feed on dead plant and animal

matter. Ex. mites, earthworms, crabs, and snails.

Food Chains

• The energy flow from one trophic level to the other is know as a food chain

• A food chain is simple and direct• It involves one organism at each trophic level

– Primary Consumers – eat autotrophs (producers)– Secondary Consumers – eat the primary consumers– Tertiary Consumers – eat the secondary consumers– Decomposers – bacteria and fungi that break down

dead organisms and recycle the material back into the environment

Food Chain

Food Chain

• Energy flows

algae→zooplankton→small fish→squid→shark

SunOr

chemicalenergy

Producers Consumers

Food chain Food web(just 1 path of energy) (all possible energy

paths)

Food Web

• In reality feeding relationships are more complex then can be shown in a food chain.

• We represent the complex network of organisms in an ecosystem with a food web. See page 71.

Food Web

Food Web

Biomass

• The total mass of the organic matter at each trophic level is called biomass

• Biomass is just another term for potential energy – energy that is to be eaten and used.

• The transfer of energy from one level to another is very inefficient (10% Law)

Biomass

Ecological Pyramid• An ecological pyramid shows the relationship

between consumers and producers at different trophic levels in an ecosystem

• Shows the relative amounts of energy or matter contained at each trophic level

• The Pyramid shows which level has the most energy and the highest number of organisms

Ecological Pyramid

Trophic Levels

Producers- Autotrophs

Primary consumers- Herbivores

Secondary consumers-small

carnivores

Tertiary consumers- top

carnivoresENERGY

Ecological Pyramid

Ecological Pyramid

• Which level has the most energy?• Which level has the most organisms?• Which level has the least organisms?• Which level has the least energy?