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4-1 The Role of Climate
Organisms vary in their “ideal” conditions
Also vary in tolerance to change
Many of these conditions or changes refer to
climate/weather
Weather vs. Climate
Weather: conditions at a
particular time and place
Climate: average conditions in
a particular region
Effected by: atmosphere,
latitude, winds, currents,
precipitation, etc.
Greenhouse
Effect
Natural situation in which heat is retained by
layer of gases (CO2, methane)
Atmosphere acts as a natural insulator
Would be 30 degrees cooler without
Latitude
Polar zones- always cold
Temperate zones- varies hot/cold
Tropical zones- always hot
Heat transfer by:
Water- currents
Air- hot air rises/cool air falls (winds)
4-2 What shapes
an ecosystem?
Habitat: area where an organism lives
Made up of:
Biotic factors: biological influences
Competitors, predators, prey
Abiotic factors: nonliving influences
Climate, nutrient availability
Niche
All factors that influence an ecosystem and how
the organism uses them
The “role” of an organism
Competition Exclusion Principle: no 2 organisms
can have the same niche
Ex: warbler bird
Community Interactions
Competition: attempt to use same resource at
same place/same time
Predation: one organisms feeds on another
Symbiosis: two species in a relationship
together
Types of Symbiosis
Mutualism: both benefit
Ex: flowers and insects
Commensalism: 1 benefits, other not effected
Ex: barnacle and whale
Parasitism: 1 benefits, other is harmed
Lives on/inside “host”- does NOT kill
Ex: tapeworm, ticks
Ecological Succession
Gradual change after a disturbance (natural or
man-made)
Primary: succession when there is no soil
Pioneer species: first to populate an area
Secondary: succession when soil is still there
4-3 Biomes
Biome: group of communities covering a large
area
Characterized by:
soil,
climate
specific plants and animals
The Biomes:
1. Tropical rain forest (ex: Brazil)
Hot and wet
Ferns, monkeys, toucans
2. Tropical dry forest (ex: India)
Warm with wet and dry seasons
Deciduous trees, tigers, elephants
3. Tropical savanna (ex: Kenya)
Warm with seasonal rain, lightning fires
Grasses, shrubs, lions, hyenas
4. Desert (ex: Arizona)
Low precipitation (dry), variable temps.
Cactus, snakes, lizard
5. Temperate grassland (ex: Texas)
Hot/cold seasons, average precipitation, fertile soil
Grasses, bison, grasshoppers
6. Temperate woodland (ex: Los Angeles)
Hot, dry summer and cool. wet winter
Evergreens, coyote, mountain lion
7. Temperate forest (ex: Philadelphia)
Moderate winter, warm summer, year round rain
Moss, coniferous trees, deer, squirrel
8. Northwestern coniferous forest (ex: Seattle)
Mild temps., cool, dry summer- otherwise wet
Conifer trees (redwood), bears
9. Boreal forest/ Taiga (ex: northern Europe)
Long, cold winter, short, dry summer
Fir trees, lynx, moose
10. Tundra (ex: Alaska)
Permafrost- layer of permanent frozen soil
Short grass, caribou, owl
Other land areas:
Mountain ranges (ex: WA state)
Factors change with elevation
Polar ice caps (ex: Antarctica)
Border tundra
Polar bears, insects
4-4 Aquatic Ecosystems
Grouped by abiotic factors
Depth (amount of light)
Nutrients available
O2 available
Freshwater (only 3%)
Flowing water- organisms adapt to
the flow
Standing water- flow in and
circulation of nutrients, O2 and heat
Freshwater wetlands- bogs,
marshes and swamps- very diverse!
Estuaries
Wetlands where rivers meet the sea
Detritus = lots of biomass
Ideal for feeding, breeding, nesting, spawning
Ex: salt marshes and mangrove swamps
Salt tolerant
Marine Ecosystems
Photic zone: well-lit upper layer
Aphotic zone: dark (200m and deeper)
Marine Zones
1. intertidal
Extreme changes with tides
Hot and dry to covered in water
Waves and currents
2. coastal ocean
Low tide mark to continental shelf
Photic areas = phytoplankton
Ex: kelp forests and coral reefs
3. open ocean
Continental shelf outwards
Low nutrients = low productivity
4. benthic- along ocean floor
Benthos: organisms that live here
Food depends on depth: photic producers,,
detritus, chemosynthesis