ECOLOGY
The Organization of Life
BASIC TERMINOLOGY
• Organism – individual
• Population – group organisms
• Community – group interacting
populations
• Ecosystem – specific geographic region
where populations interact with one
another & the environment
BASIC TERMINOLOGY
• Habitat – where organism lives
• Biosphere – portion earth supports life
• Niche – organism’s role/job
FACTORS IN ECOSYSTEM
• ABIOTIC
– Non-living
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Sun
Water
Temperature
Air
Soil quality
Salinity
Weather
• BIOTIC
– Living
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Plants
Animals
Bacteria
Fungi
NICHES
• Autotroph/producer • Heterotroph/consumer
– Makes own food
– Green plants
– Gets energy from
consuming other
organisms
– Animals, mushrooms
NICHES
• Herbivore
• Carnivore
– Eats plants
• Omnivore
– Eats both plants/animals
– Eats meat
NICHES
• Scavenger
– Eats carrion
• dead material
• Decomposer
– Decays (breaks down)
dead matter
PREDATOR/PREY
• Predator
– hunter
• Prey
– hunted
SYMBIOSIS
• Commensalism
– Long-term
interaction of 2
organisms where:
• 1 benefits
• 1 unaffected
SYMBIOSIS
• Mutualism
– Long term
interaction where
both species benefit
SYMBIOSIS
• Parasitism
– Long term
interaction where:
• 1 species benefits
• 1 species is harmed
FOOD CHAIN
• Shows transfer of energy
FOOD WEB
• Shows all relationships in ecosystem
ENERGY OR BIOMASS PYRAMIDS
SUCCESSION
• Natural changes in an ecosystem over
time
PRIMARY SUCCESSION
• Occurs in newly
formed areas –
never inhabited
before
– Newly formed
islands
– Cooled lava spills
– After landslides
(newly exposed
surfaces)
SECONDARY SUCCESSION
• Occurs in previously
colonized, but
disturbed or
damaged areas
– Fires, natural
disaster
– Farming
– Clear-cutting
– Construction
– Introduction foreign
species
PIONEER COMMUNITY
• 1ST organisms
inhabit an area
• Gradual buildup
from simple 
more complex
• Bacteria 
simple producers &
consumers 
complex producers
& consumers
CLIMAX COMMUNITY
• Stable & mature
• Little change occurs
• Large diversity of complex species
Stages in Ecological Succession
POPULATION DYNAMICS
• Populations experience exponential
growth
POPULATION DYNAMICS
Density Dependent Factors
Density Independent Factors
• Impacted by population
• As population
increases, the affects
of these factors also
increases
• Not impacted by
population
• Same affect regardless
of population
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Disease
Competition
Predation
Reproduction
– Natural disasters
– Weather patterns
LIFE HISTORY PATTERNS
Rapid
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Small
Short life span
Quick gestation period
Many offspring
Little parenting
Slow
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Large
Long life span
Long gestation period
Few offspring
Increased parenting
LIMITS ON POPULATIONS
• Predation – eliminate slow, weaker
species of group
• Competition – survival of fittest,
compete limited resources
• Crowding – causes increases in stress
– Causes decreases in fertility rates &
parenting skills
– Causes increase in hostility rates
NUTRIENT CYCLES
NUTRIENT CYCLES
NUTRIENT CYCLES
NUTRIENT CYCLES
LIMITING FACTORS
• Abiotic factors that restrict the survival
of living things.
• Used to separate/identify biomes
– Geographic regions with unique
characteristics
• Examples:
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Temperature
Precipitation
Oxygen
Salinity
Sunlight
MARINE BIOME
•Characteristics: high salinity (salt)
•Location: oceans & seas
•Vegetation: seaweed, kelp,
•Animals: shrimp, jellyfish, shark,
whales
•Terms:
•Photic zone – shallow (light pass
thru)
•Aphotic zone – deeper (no light)
ESTUARY
•Characteristics: tidal zone, range
salinity
•Location: bays, tidal zones, gulf region
•Vegetation: grasses
•Animals: birds, snails, clams, oysters,
crabs, starfish
•Terms:
•Intertidal zone – area btw high & low
tides
FRESHWATER BIOME
•Characteristics: little/no salinity
•Location: lakes, streams, ponds,
rivers
•Vegetation: algae, cattails, grasses
•Animals: fish, insects, crayfish, frogs
•Terms:
•Turbidity – moving water
•More movement = more oxygen
TUNDRA
•Characteristics: treeless, long
summers, little winter sun, poor soil
•Location: Canada, Russia, Alaska
•Vegetation: grasses, moss lichen
•Animals: insects, fox, rodents,
caribou, reindeer
•Terms:
•Permafrost – permanently frozen
ground
TAIGA
•Characteristics: coniferous forest,
poor soil, long severe winter
•Location: Canada, N. Europe, N.
Asia
•Vegetation: pine, fir, hemlock,
spruce
•Animals: rabbits, lynx, caribou,
moose, woodpecker
TEMPERATE FOREST
•Characteristics: deciduous trees, 4
seasons
•Location: East US, Europe
•Vegetation: Maple, Oak, Birch,
Hickory
•Animals: bear, deer, robins, raccoon
•Terms:
•Deciduous – trees lose leaves
TROPICAL RAIN FOREST
•Characteristics: warm, wet, humid,
most diversity
•Location: islands, equatorial regions
•Vegetation: broad lush plants,
flowers, vines, palms, fruit trees
•Animals: monkey, sloth, frogs,
snakes, parrots
DESERT
•Characteristics: dry & arid
•Location: SW US, N. Africa, Middle
East
•Vegetation: cacti, creosote bushes
•Animals: rodents, snakes, lizards,
scorpions, turtles, hawks
•Terms:
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Succulent - cactus
GRASSLANDS
•Characteristics: ideal growing season, good
soil quality, dry
•Location: central regions
•Vegetations: grass, grains, crops,
wildflowers
•Animals: bison, prairie dogs, birds, lions,
elephants
•Terms:
•Prairie – US
•Steppe – Russia
•Savanna – Serengeti
•Pampas - Argentina