Unit 1-Ecology

Chapter 3-The Biosphere

Ecology

Study of interactions among organisms & between organisms and their environment

Ernst Haeckel

1866 coined word “ecology” Based on oikos = “house”

Levels of organization in an organism

Chemicals make up cells…

Which make tissues…

Organs… Systems… And finally, the

individual organism

Levels of organization in ecology In Ecology, we begin with the

individual and move through the levels to the planet, Earth

Species

Group of organisms with similar characteristics Able to breed and produce fertile offspring

Species Hybrid

Populations Group of individuals

(of the same species) that live in the same area

Example? All the fire ants in

a pasture

Community

Groups of different populations that live together

Examples? All the ants, birds,

grass, cows, etc in a pasture

Ecosystem

Collection of all organisms (biotic) that live in a particular area, together with their non-living (abiotic) parts of an environment

Examples of abiotic factors??

Climate, soil type, amount of rainfall, etc

Southern Pine Ecosystem

Fort Bragg, North Carolina

Biomes A group of ecosystems that have the same A group of ecosystems that have the same

climates, and similar dominant communitiesclimates, and similar dominant communities

Biosphere Contains the

combined portion of the planet in which all life exists, including land, water, and air (atmosphere)

specifically… 11 kilometers below ocean floor and 8 km above Earth’s surface

Energy flow through the biosphere Autotrophs (producers)

organisms that make their own food

Heterotrophs (consumers) Rely on other organisms for their food supply

What’s the ultimate source of energy for all life?

AUTOTROPHS

Water + CO2 Sugar + O2

HETEROTROPHS

Sugar + O2 water + CO2

Food chain

Series of steps in which organisms transfer energy by eating and being eaten

Arrow always points to the consumer

Trophic levels

Food Chain

The pathway of energy that DECREASES as it passes through the trophic (feeding)

levels

Food web

Network of complex interactions, linking all of the food chains together

Producers

(autotrophs) organisms who make

their own food using materials from the environment

Examples? plants and algae

Consumers (heterotrophs) must get food from some outside source

by ingestion or absorption

Examples? Animals,

Fungus Most bacteria

Herbivores (a.k.a. primary consumers)feed directly on producers

Types of Consumers:

Carnivores (a.k.a.secondary consumers) feed on other animals

Types of Consumers:

Omnivores feed on both plants

and animals can be either primary

or secondary consumers, depending on food chain

Types of Consumers:

Detritivores feed on (and recycle) dead or decaying matter completing the chain, by returning nutrients needed

by producers to the environment

Scavengers eat dead things but do not recycle

Decomposers feed on dead things AND recycle them

Types of Consumers:

Ecological Pyramids

Energy Pyramid Biomass Pyramid Pyramid of numbers

Hawk-eye Question: Why are they shaped as a pyramid?

What is the relationship between the numbers of producers and Consumers?

How does this relate to the energy flow through the

ecosystem?

pyramid of numbers

So fewer and fewer organisms can be

supported at each level

ONLY 10% of energy is passed on to next levelEnergy Pyramid

Biogeochemical cycles:

Water (hydrologic) cycle

Driven by solar energy

Recycles water, which is primary component of all life

Carbon Cycle

driven by photosynthesis & respiration

recycles carbon, a primary component of all organic compounds

CO2 in Atmosphere

CO2 in Ocean

Nitrogen Cycle driven by decomposition by nitrifying bacteria and fungi atmospheric nitrogen must be converted to a usable

(by plants)form

N2 in Atmosphere

NH3

NO3 –

and NO2 –

Phosphorus Cycle

driven by decomposing bacteria & fungi

phosphorus is an important component of ATP, Nucleic acids, & phospholipids

The Nature of Cycles

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