Ecosystems and Communities

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Transcript Ecosystems and Communities

Ecosystems and
The Role of Climate
O Weather- Condition of Earth’s atmosphere at a
particular time and place
O Climate- Determined by temperature and moisture
O Temperature- Determined by latitude and altitude
O Greenhouse Effect
O Ozone lets sunlight through but retains the heat it
O Adding CO2 to the air increases the greenhouse
O Removal of CO2 from the air by photosynthesizing
plants and algae decreases the effect
The Role of Climate
O Winds
O Winds are driven by uneven heating of Earth’s
O Hot air near equator rises- Cold air over poles
O The curved paths of some winds are caused by
Earth’s rotation (Coriolis Effect)
O Currents:
O Currents- Similar patterns of heating and cooling
occur in Earth’s oceans- Cold water near poles
sink- Water rises in warmer regions
The Role of Climate
O Geography Affects Climate
O Mountains cause moist air to rise- the air
mass cools, moisture condenses,
precipitation occurs, far side of mountain is
dryer resulting in fewer plants
Ecological Relationships
O Habitat
O A habitat is the place where an organism
lives out its life
O Niche
O A niche is the role or position a species has in
its environment- how it meets its specific
needs for food and shelter, how and where it
survives, and where it reproduces in its
Ecological Relationships
O Niche
O Competitive Exclusion Principle- No two
different species can occupy the same niche
in the same habitat at the same time
O Fundamental Niche includes resources an
organism could theoretically use (if no
O Realized Niche includes resources it actually
does use given competition from other
Ecological Relationships
O Interspecific Interactions
O Interspecific interactions are interactions that
occur between populations of same species
living together in a community
O There are 4 major interspecific interactions:
Predation (and parasitism), Competition,
Commensalism & Mutualism
O Predation (parasitism)
O The interaction is beneficial to one species
and detrimental to the other
Ecological Relationships
O Predation
O Predation: When a predator eats its prey
O Parasitism: Predators that live in/on their
hosts, usually feeding off their body tissues
or fluids
O Usually do not kill their hosts
O Defense Against Predation
O Animals defend themselves against
predators passively (hiding) or actively
Ecological Relationships
O Defense Against Predation
O Disruptive coloration (camouflage) makes prey
difficult to spot
O Aposematic coloration (warning coloration) warns
predators not to each animals that may be toxic or
may sting
O Mimicry- When a species “imitates” or “mimics”
O Batesian mimicry: When one edible or harmless
species mimics an bad tasting (unpalatable) or
harmful species
O Mullerian mimicry: Two species, both of which are
unpalatable (taste bad) or harmful, resemble each
Ecological Relationships
O Symbiosis
O Living together
O The relationship in which there is a close and
permanent association between organisms of
different species is called symbiosis
Type of Symbiosis Definition
Both benefit
One benefits, one no effect
One benefits, one harmed
Ecological Relationships
O Succession: Changes over Time
O The orderly natural changes and species
changes that take place in an ecosystem is
O Succession occurs in stages. At each stage,
different species of plants and animals may
be present
O As succession progresses, new organisms
move in
O Others may die out or move out
Ecological Relationships
O Primary Succession
O The colonization of new land by communities of
organisms is called primary succession
O The first species to take hold in an area like this
are called pioneer species, usually lichens
O Decaying lichens, along with bits of sediment in
cracks and crevices of rock, make up the first
stage of soil development
O New soil makes it possible for small weedy plants,
small ferns, fungi, and insects to become
Ecological Relationships
O Primary Succession
O After some time primary succession slows
down and the community becomes fairly
stable, or reaches equilibrium
O A stable, mature community that undergoes
little or no change in species is a climax
Ecological Relationships
O Secondary Succession
O The sequence of changes that takes place
after an existing community is severely
damaged in some way
O Secondary succession, however, occurs in
areas that previously contained life, and on
land that still contains soil
O Because soil already exists, secondary
succession may take less time than primary
to reach a climax community
Ecological Relationships
O What is a Biome?
O A biome is a large group of ecosystems that
share the qualities of climax community
O Ranges of Tolerance
O The ability of an organism to withstand
variations in biotic and abiotic environmental
factors is known as tolerance
Biomes- Tundra
Cold and dry
Permafrost- area of soil
that remains frozen year
Short, cool summers
Flora (Plants)
low shrubs, mosses,
flowers, lichen
Fauna (Animals)
caribou, hares , foxes,
wolves, and polar bears
Biomes- Taiga
Taiga Boreal Forest
Long cold winters, short,
mild summers
More rainfall than the
Taiga= Spruce- Moose
spruce, fir, moss
bear, eagle, wolf, owl, otter
Biomes- Temperate Deciduous
Temperate Deciduous
Cold winters
Warm summers
Moderate rainfall
oak tree, pine tree, flower,
eagle, bear, deer, squirrel
Biomes- Grassland
Low rainfall
Long dry periods
Occasional fires
Few trees
grasses, flowers
coyote, prairie dog,
Biomes- Desert
Low rainfall
Usually have high
temperatures but may be cold
Growing season occurs after it
lizard, rat, owl
Biomes- Tropical Rain Forest
Tropical Rain Forest
High temperatures
High levels of rainfall
High humidity
Dense growth of vegetation
that does NOT shed its leaves
Most of the nutrients are tied
up in living material
Most productive biome
Most diverse biome
bamboo , trees, figs
bat, monkey, sloth, snake
Biomes- Chaparral
Winter, rainy season
Summer draught
Shrubby trees
sage brush, low shrubs
foxes, rabbit, roadrunner
Ecological Relationships
O Aquatic Biomes
O More than 70% of earth’s surface is covered
with water
O Most of that water is salt water
O Freshwater is confined to rivers, streams,
ponds, and most lakes
O Most of earth’s food and O2 production
(photosynthesis) takes place in the water
Ecological Relationships
O Aquatic Biomes
O Most stable ecosystems on Earth. The
amount of O2 and CO2 available, amount of
suspended or dissolved materials are stable
over very large areas and show little tendency
to change
Ecological Relationships
O 3 Types of Fresh Water Biomes
O Moving Water- rivers, streams
O Standing Water- lakes, ponds
O Wetlands- ecosystem where water saturates the
O Marshes- shallow wetlands along rivers
O Swamps- presence of trees and shrubs
distinguishes swamps from marshes
O Bogs- typically form in depressions where water …
O Estuary- shallow area where a river meets the sea
and fresh water and salt water mix (brackish)
Ecological Relationships
O The Chesapeake Bay
O The largest Estuary in the U.S.
O Home to more than 3,600
O Serves as a spawning and
nursery grounds for fish
O Main producers are submerged
aquatic vegetation
Ecological Relationships
O Marine Biome Zones
O Photic Zone- area where light penetrates into
the water (about 200m)
Aphotic Zone- no light
Intertidal Zone- area between low tide and
high tide
Neritic Zone- shallow area on continental
shelf that is always covered with water
Benthic Zone- bottom surface