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
Click on image to play video.