Communities
&
Biomes
Communities
• Have you ever wondered why we don’t
have polar bears in Mississippi?
• Why we don’t have grizzly in Mississippi?
• Abiotic and biotic factors interact and
result in conditions that are suitable for life
for some organisms and unsuitable for
other organisms.
Abiotic and biotic factors
Polar bears live near the north pole. Their
white fur makes them hard to distinguish
from the surrounding ice and snow,
enabling them to stalk the seals and
walruses that serve as their primary food.
Limiting factors
Environmental factors that affect an
organism’s ability to survive in its
environment, such as food availability,
predators, and temperature, are limiting
factors.
Ranges of tolerances
Some species can tolerate conditions that
another species cannot, for example,
catfish can live in warm water with low
amounts of dissolved oxygen, which other
fish species such as bass or trout, could
not tolerate.
All species have a certain range of
tolerances that they can withstand.
Succession
If grass were no cut on a lawn, what would it
look like in one year, five years, and
twenty years?
Ecologists refers to the orderly, natural
change and species replacements that
takes place in the communities of an
ecosystem as succession.
Primary Succession
Lava flowing from the mouth of a volcano is
so hot it destroys everything in its path, but
when it cools it forms new land.
This new land is un-colonized by any life
until a pioneer species begins to settle it.
The colonization of new species is called
primary succession.
Pioneer Species
• Lichen- is an example of a pioneer species
it is a combination of alga and fungus.
Climax Community
After the primary succession and species
have changed many times a relatively
stable community appears this community
is known as a climax community.
A climax community is characterized by
complex food webs, many different
species of organisms, and little or no
succession.
Secondary Secession
Secondary Secession refers to the
sequence of community changes that
takes place after a community is disrupted
by natural disasters or human actions.
Biomes
A biome is a large group of ecosystems that
shares the same type of climax
community.
The Biosphere is divided into regions called Biomes. Each
Biome is occupied by characteristic communities or
ecosystems of plants and animals that share adaptations
which promote survival within the biome.
Aquatic Biomes
The portion of the marine biome that is
shallow enough for sunlight to penetrate is
called the photic zone.
Deeper water that never receives sunlight is
called the aphotic zone.
Marine Biomes = Saltwater
Ocean Zones
– Photic Zone = sunlight area
– Aphotic Zone = cold, dark
area
– Intertidal Zone = area
between high & low tides
(area in & out of water twice
a day)
– Neritic Zone =shallow,
sunlight area of ocean
– Oceanic Zone = the rest of
the open ocean
Marine Biome
include Estuaries (where oceans meet rivers)
bays, mud flats, and salt marshes
• lots of light
• lots of nutrients
• large variation in temperature
and salinity
• some areas exposed to air
during low tide
• plants include trees, grasses,
and seaweed
• animals include birds, fish,
clams, crabs, and shrimp
Estuary
Aquatic Biomes
• An estuary is a coastal body of water, partially
surrounded by land, in which freshwater and
saltwater mix.
Aquatic Biomes
The portion of shore line that lies between the high
and low tide lines is called the intertidal zone.
Intertidal Zones
(where oceans meet land)
• area exposed to air twice
a day during low tide
• organisms must protect
themselves from
dehydration and crashing
waves
• plants include Fucus,
Laminaria, kelp,
• animals include crabs,
mussels, sea stars, sea
anemones, chitons, and
snails
Marine Biome
Continental Shelf
(the shallow oceans that border continents)
Alaska
Bering
Sea
Shelf
Plankton are small organisms, that live in
the waters of the photic zone.
Neritic Zones
(area over the continental shelf)
• area where
photosynthesis takes
place
• most productive area of
the ocean
• plants include plankton,
and seaweeds like
Sargassum
• animals include coral,
mollusks, crustaceans,
sea turtles, and fishes
Marine Biome
Coral Reef
(masses of corals that reach the ocean surface)
Marine Biome
Pelagic Ocean
•
•
•
•
low nutrient levels
low productivity
part light, part dark
wide range of pressure and
temperature
• contains fewer species
• producers include photosynthetic
protists and bacteria at surface, and
chemosynthetic bacteria at volcanic
vents
• consumers include fish, whales,
dolphins, clams, crabs, and worms
Aphotic zone
• In the aphotic zone where the lack of light is
darker than any night, and the pressure is hundred
of pounds per square cm. there are still organisms
that survive. 90% of the ocean is more than a km.
deep. Organism that live at these depth still depend
on sunlight, even if it is indirectly, for energy.
What adaptations might help these organisms survive
in this environment?
Marine Biome
Pelagic Ocean
(the deep ocean)
Freshwater Biomes
include ponds, lakes,
• have low salt concentration (most freshwater
biomes have less than 1% salt)
• plants include lilies, algae, rushes, cattails
• animals include birds, fish, otter, beaver
• two types:
– Eutrophic = rich organic matter and
nutrients, and murky
– Oligotrophic = very little organic matter
Freshwater Biomes
Streams and Rivers
• have low salt concentration
• water flows down a slope
– the greater the slope, the
faster the current and the
lower the nutrients
• higher concentrations of O2
• plants include algae, cattails, shrubs,
• animals include fish, birds, snails,
flatworms, insect larvae….
Terrestrial Biomes
• characterized and named according to the climax
vegetation
• climax vegetation determines which animals will live there
• eight types– Tropical Forest
– Savannah/Grasslands
– Desert
– Temperate Deciduous Forest
– Northern Coniferous Forest
– Taiga
– Tundra
– Polar Region
TUNDRA
• Terrestrial = land
• Tundra- a treeless land with long
summer days and short periods of
winter sunlight
• Permafrost- frozen layer of soil that lies
only a few inches from the surface.
(Permanently frozen)
Tundra
• is extremely cold and dry
• short growing season and
permafrost (permanently
frozen soil)
• during the summer, the
thawing topsoil supports a
grassland type community
with grasses, sedges,
mosses and other vegetation
tolerant of soggy soils
• Animals include caribou,
musk oxen, owls, foxes,
hares, and wolves
Taiga
• winters are cold, and
precipitation is in the
form of snow.
• Soil is low in nutrients
and highly acidic
• are characterized by
coniferous forests
(pines, firs, and other
trees with needles).
•Taiga- a and of larch, fir, hemlock, and
spruce trees, also called the northern
coniferous forest.
Temperate Deciduous Forest
• Temperate forest- Broad-leaved hardwood trees
lose their foliage annually (70 to 150 cm)
• This area is dominated by deer, rabbits, squirrels
and black bear.
Temperate Deciduous Forests-
• have warm summers and cold winters (red), moderate precipitation
(green), and rich soil with decaying organic matter and worms and fungi.
• contain deciduous trees that shed their leaves during the winter (beech,
birch, maple, oaks, and willows), an adaptation to poor growing conditions
(short days and cold temperatures).
• animals include deer, fox, woodchucks, and squirrels
Grasslands
• Grasslands- Large communities covered
with grasses and similar small plants.
• Grasslands contain fewer tan ten to fifteen
trees per hectare, though larger numbers
of trees are founds near streams and other
water sources.
Temperate
Grasslands
• receive less water
and are subject to
lower temperatures
than are savannas.
• the North American
prairie is an
example.
Savannas• subject to high
temperatures (red), and
low rainfall (green).
• are tropical-subtropical
grasslands with scattered
bushes and trees.
• animals include longlegged, hoofed herbivores
(like bison, antelopes,
cattle, and zebras).
Desert
• Desert- an arid region with sparse to almost
nonexistent plant life.
• Deserts usually get less than 25 cm of
precipitation annually.
• Desert plants sometimes have spines, thorns, or
poisons that act to discourage herbivores.
• Desert animals are usually small nocturnal
creatures. (Kangaroo rat)
Deserts• are hot and dry.
• soil is sandy and nutrient poor
• growth of annual plants is limited
to short periods following rains.
• other plants have adapted to the
hostile conditions with leathery
leaves, deciduous leaves, or
leaves reduced to spines (cacti).
• many animals have thick skins,
conserve water by producing no
urine or very concentrated urine,
and restrict their activity to nights.
Tropical Rain Forest
• Tropical Rain Forest- have warm temperatures,
wet weather, and lush plant growth. (200-600
cm)
• The tropical rain forest is home to a diverse
range of species. (more species per square acre
than any other place)
Tropical Rain Forests
• are characterized by high temperature
(red) and heavy rainfall (green).
• vegetation consists mostly of tall trees
that branch only at their tops, forming a
spreading canopy that allows little light to
reach the forest floor.
• epiphytes (plants that live on other
plants) and vines commonly grow on the
trees, but due to lack of light, little grows
on the forest floor.
• typical animals include monkeys, lizards,
snakes, and birds.
Question 1
• The removal of which of the following
organisms would have the biggest impact
on a marine ecosystem?
• A. Fishes
• B. Whales
• C. Shrimp
• D. Plankton
Question 2
• An undersea volcano erupts creating a
new island off the coast of South Carolina.
Life slowly starts appearing on the island.
What would probably be the first species
to grown and survive?
• A. Maple trees
B. Finches
• C. Linchens
D. Grasses
Question 3
• The changes in communities that take
place on a new island would best be
described as _________.
• A. Primary succession
• B. Secondary succession
• C. Tertiary succession
• D. None of the above
Question 4
• Which of the following is true?
• A. Temperature forests have more rainfall
than tropical rain forests.
• B. Tropical rain forests have more species
of trees than temperate forests.
• C. Temperate forests are closer to the
equator than tropical rain forests.
• D. Tropical rain forests are younger than
temperate forests.
Question 5
• The annual rainfall is 300 cm and the
average temperature is 15°C. What type
of forest is being described?
• A. Tropical rain forest
• B. Coniferous Forest
• C. Temperate Rain Forest
• D. Temperate Forest
Question 6
• A lack of food prevents further growth in a
deer population. This is an example of a
__________.
• A. Range of tolerance
• B. Limiting factor
• C. Photic zone
• D. Biome
Question 7
• A deep sea fisherman catches an ocean
fish. This fish, like others of the same
species, has no developed eyes. Its
habitat is most likely the ___________.
• A. Intertidal zone
• B. Aphotic zone
• C. Photic zone
• D. Zone of intolerance
Question 8
• Locations of biomes are usually
determined by ______________.
• A. Temperatures and altitude
• B. Temperatures and precipitation
• C. Altitude and precipitation
• D. Soil type and temperature
Question 9
• The kangaroo rat conserves its water and
obtains all its from the food it eats. In what
ecosystem is the kangaroo rat more likely
to live?
• A. Tropical rain forest
• B. Taiga
• C. Desert
• D. Savanna
Question 10
• The layer of frozen soil found in the tundra
is called __________?
• A. Permasoil
• B. Permafrost
• C. Permafreeze
• D. Permadirt