Transcript File

Kinds of Ecosystems
J. Quigley- 2016
Biomes
• Earth is covered by hundreds of types of
ecosystems. For convenience ecologists group
these ecosystems into a few biomes
Biomes
• Biomes are areas that
have distinctive
climates and organisms
• Each biome contains
many individual
ecosystems
• Locations of all the
major biomes are
mapped out
Biomes
• Biomes are usually named
for the plant life they
contain
• Climate determines plant
life.
• Plant life determines
animal life
• Animal and plant life
determine bacteria, other
microorganisms and
decomposers in the area
Biomes
• The major biomes are:
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–
–
–
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–
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Tropical rain forest
Temperate forest
Taiga
Savanna, temperate
grasslands and chaparral
Desert
Tundra
Mountains/Ice
Water
Tropical Rain Forests
• Tropical Rain Forest:
occurs in a belt around
the earth near the
equator
• Always humid and warm
• Gets about 250cm of rain
each year
• Strong sunlight year
round
• Fairly constant climate
and little seasonal
variation in temperature
Tropical Rain Forests
• Tropical Rain Forests have a climate ideal for growing plants which
flourish year round
• The warm and wet conditions nourish more plant species than any other
biome
• The soil is thin and poor, but the rapidly decaying plants and animals
after death returns nutrients to the soil to be used again
• Because the soil is thin, most tropical rain forest plants have roots that
grow sideways instead of deep.
Tropical Rain Forests
• Rainforest plant
adaptations: trees and
plants grow in layers
– Trees more than 30m tall
form the dense canopy that
absorbs at least 95% of the
sunlight
– Below the canopy is the
understory, only trees and
shrubs adapted to shade can
live here; When a tree dies,
seedlings grow quickly to outcompete other trees for the
new space
– Forest floor is the bottom
layer
Tropical Rain Forests
• Tropical rain forest animal adaptations
– The incredible diversity of rain forest vegetation may have
lead to the evolution of the greatest diversity of animals
anywhere on earth
– Most rainforest animals are specialists
– A specialist is an organism adapted to use a specific
resource in a particular way to avoid competition.
Tropical Rain Forests
• Tropical Rain Forest
Adaptations:
– Some animals have
evolved elaborate
methods for escaping
predators
– Other have evolved
equally sophisticated
methods for capturing
prey
– Camouflage and mimicry
is common
Forests
• Threats to the rain forest:
– The rain forest used to
cover 20% of the entire
earth, today it is less than
7%.
– This is due to logging, clear
cutting and farming
– You can help the rain forest
by buying products that
promote sustainable use of
rainforests
Temperate Rain Forest
• Temperate rain forests occur in North America, South
America, Australia and New Zealand.
• The Pacific NW is home to North America’s only
temperate rain forests… where tree branches are
draped with mosses, tree trunks are covered in
lichens and the forest floor is covered in lush ferns
Temperate Rain Forest
• 300 foot tall evergreen
trees such as Sitka Spruce
and Douglas Fir dominate
the forest
• Moisture is very high in
this cool, humid forest
• It has high rainfall and
moderate temperatures
• It has become the subject
of controversy in recent
years because of conflicts
over logging.
Temperate Deciduous Forests
• A walk though N.
American deciduous
forest in the fall is very
colorful.
• Deciduous trees lose
their leaves every fall
and grow them back
every spring. Deciduous
trees are dominant in
this forest
Temperate Deciduous Forests
• Trees drop their broad,
flat leaves each fall
• Seasonal variations can
be extreme
• The growing season lasts
for four to six months
• Summer temperatures
are about 35⁰C (95⁰F)
• Winter temperatures are
well below freezing
Temperate Deciduous Forests
• Deciduous forests are
moist, receiving
between 75-250cm
(300-100 inches) of
rainfall each year
• The rain and snow help
decompose dead
organic matter, such as
fallen leaves, which in
turn contributed to the
rich, deep soil.
Temperate Deciduous Forests
• Plant Adaptations: Similar
to the tropical rain forest,
deciduous forests also
grow in layers.
– The forest canopy is
dominated by tall trees
like: maple, oak and birch.
– Small trees, shrubs and
bushes abound in the
understory
– The forest floor gets more
light than a rainforest and
more plants: ferns, herbs
and mosses
Temperate Deciduous Forests
• Temperate forest plants are
adapted to survive seasonal
changes
• In winter, when ice locks up
moisture in the soil, deciduous
trees shed their leaves. Herb
seeds, bulbs and underground
stems become dormant
underground
• In the spring as sunlight
increases and temperatures
rise… trees put out new
leaves, seeds germinate and
underground stems and roots
make new shoots.
Temperate Deciduous Forests
• Animal Adaptations: The animals are adapted to exploit
the forest plants for food and shelter
– Squirrels eat the nuts, seeds and fruits in the treetops
– Bears feast on the leaves and sweet berries of forest plants
– Deer and other browsers nibble leaves from trees and shrubs
Temperate Deciduous Forests
• Many birds nest in the
relative safety of the
canopy.
• Most birds are
migratory, meaning
they fly south for the
winter and north for
the summer
• Many animals (bears,
insects, reptiles)
become dormant
(hibernate) for the
winter
Taiga
• The taiga terrain is
rough and vegetation is
minimal
• It is the northern
coniferous forests,
which is extremely cold,
with average below
freezing temperatures
• The growing season
may be as short as 50
days!
Taiga
• Plant Adaptations:
– Conifers are trees that are
evergreen, have a cone
shape that helps it shed
the snow, long thin needles
(leaves) and include: pine,
hemlock, fir and spruce
– When conifers shed their
needles, they release acid
into the soil. Most plants
can’t grow in acidic soil, so
the Taiga has few plants.
Blueberries, a few ferns
and mosses only.
Taiga
• Animal Adaptations:
– The taiga has many lakes and swamps
that in the summer attract birds that
feed on insects, fish or other wetland
organisms
– Many birds migrate south to avoid the
winter
– Some year round residents such as
shrews and voles burrow underground
for the winter
– Moose and arctic hares eat what
vegetation they can find
– Predators like: Lynx, wolves and foxes
change from brown in the summer to
white in the winter
Grasslands
• Climates where there is less rainfall, forests give way to
savannas, grasslands and chaparral, which in turn give way
to deserts.
• As precipitation decreases, so does the diversity of species
present
• While the number of different species if often smaller, the
number of individuals of each species present can be quite
large
• Far to the north, another type of desert occurs, called the
tundra.
• Like the desert, little precipitation occurs in the tundra, but
unlike the desert, temperatures stay very cold all year
Savannas
• Savannas contain the
greatest collection of
grazing animals on Earth!
• Along with magnificent
predators that hunt them
• Savannas are found in the
tropics near the equator
• They get too little rain for
many trees to grow
Savannas
Plant adaptations
• Savanna trees and grasses
have large underground root
systems that survive fire, so
plants regrow quickly after a
fire
• The root systems also help the
plants survive during the dry
season
• Coarse savanna grasses have
vertical leaves that help
conserve water
• Trees and shrubs often have
thorns or sharp leaves to deter
hungry herbivores
Savannas
Animal Adaptations:
• Large grazing herbivores such as:
elephants, giraffes, zebras,
wildebeests and gazelles have
adopted a migratory way of life,
they follow the rains to areas of
newly sprouted grass
• Some predators such as: lions,
hyenas and cheetahs, follow this
mobile food source
• Herbivores avoid competition by
grazing on food of different
heights:
– Small gazelles graze on grasses
– Black rhinos eat shrubs
– Giraffes feed on tall tree leaves
Temperate Grasslands: Prairies,
Steppes and Pampas
Temperate Grasslands:
• Have tall grasses and little
water
• Have the most fertile soil of
any biome on earth
• Are found in the interiors of
continents where there is too
little rainfall for trees to grow
• Mountains often play a role in
maintaining grasslands (as
they block the rain)
• Usually only about 25cm of
rainfall each year
• Very hot summers, often so
hot fires are common
Temperate Grasslands
Plant Adaptations:
• Prairie grasses are
perennials, meaning they
survive from year to year
• Their root systems form
dense mats that survive
drought and fire, and
holds the soil in place
• The amount of rainfall
determines which types
of grasses grow in a
particular area
Temperate Grasslands
Animal Adaptations:
• Grazing animals such as
antelope and buffalo have
large, flat back teeth for
chewing coarse prairie grasses
• Predators like wolves and
coyotes feed on herbivores
• Larger animals cope with
severely cold winters by
growing thick coats of fur
• Smaller animals like badgers,
prairie dogs and even owls,
live in protected underground
burrows
Temperate Grasslands
Threats:
• Cultivation (farming) and
overgrazing have changed
grasslands
• Grain crops that have
replaced native grasses
cannot hold the soil in place
as well because their roots
are shallow and soil erosion
is a problem
• Overgrazed grasses are
constantly being chewed
down and cannot grow fast
enough to reproduce
Chaparral
• A biome that occurs in
the mid-latitudes.
• Mostly in costal areas
• Dry hot summers and
mild, wet winters with
slight variations in
seasonal temperature
Chaparral
Plant Adaptations:
• Chaparral plants are
mostly low lying
evergreen shrubs and
small trees
• Common plants include:
chamise, manzanita,
scrub oak, olive trees and
cooking herbs like sage
and bay
• These plants have small,
leathery leaves that resist
water loss
Chaparral
Animal Adaptations:
• Camouflage is the most
common adaptation of the
chaparral
• Animals such as the quail,
lizards, chipmunks and mule
deer have brownish gray coats
to let them move unseen
through the brush
• Chaparral animals are also
adapted to seasonal
differences in food: the scrub
jay, for example, has a beak
that is adapted to eat insects,
seeds and other birds eggs
Chaparral
Threats:
• Biggest threat is human
development
• Because the biome has
a lot of sun, access to
the ocean and a mild
year-round climate,
people have
overdeveloped almost
all chaparral areas
Deserts
• Areas that receive less
than 25cm of
precipitation each year
• Deserts closer to the
equator are hotter than
those that are not
• Temperatures in the hot
months can average as
much 37⁰C (100⁰F)
• Deserts often occur in the
rain shadow of mountains
that block moisture-filled
clouds
Deserts
Plant Adaptations:
• Have adaptations for obtaining
and conserving water
• Succulents and cacti have
thick, fleshy stems and leaves
that store water. They also
have a waxy coating to prevent
water loss
• Cactus spines help deter
herbivores from eating the
plant’s juicy flesh
Deserts
Plant adaptations:
• Rainfall rarely penetrates
deeply into the soil, so plant
roots are spread out widely
just under the surface
• The plants all have a survival
strategy called “drought
resistance”; they can live
through the worse desert
conditions
• Some plants escape drought
by dying and dropping their
seeds when they die so they
can re-grow during the next
rain.
Deserts
Animal Adaptations:
• Reptiles, such as Gila monsters and
rattlesnakes, have thick, scaly skin
that prevents water loss
• Amphibians, such as the spadefoot
toad, survive summers by estivating
(burying themselves in the ground
and sleeping through the dry season
• Desert insects and spiders are
covered with body armor that helps
them retain water
• Most desert animals are active at
night when the air is cooler.
Deserts
Threats to Deserts:
• Residential development
continues to encroach upon
desert areas in the American
West (like Las Vegas, Nevada)
• Off-road and all-terrain vehicles
kill desert vegetation and
destroy the habitats of
endangered animals like the
desert tortoise
• Some desert plants are prized by
collectors, who remove them
from endangered plant
populations
Tundra
• Tundra is a biome without tall
trees that lies north of the Arctic
Circle
• The frozen tundra soil supports
mostly tough grasses and shrubs
• Summers are short and only the
top few inches of the soil thaws;
underneath is permafrost
(permanently frozen soil)
• Because of the permafrost, the
tundra has a lot of bogs and
swamps
• Because of the swamps and bogs,
summer time is ideal breeding
grounds for insects like mosquitos
and blackflies
Tundra
Plant Adaptations:
• Mosses and lichens, which
can grow without soil,
covers acres of rocks in the
tundra
• Where soil exists it is thin,
and plants have wide,
shallow roots that also
anchor them against arctic
winds
• Most flowering plants of the
tundra such as the moss
campion and gentian are
tiny
Tundra
Plant Adaptations:
• Being low to the ground
helps plants absorb heat
from the soil and
prevents them form being
blown over by wind
• Woody plants such as the
willow and juniper have
evolved dwarf forms,
growing flat or trailing
along the ground.
Tundra
Animal Adaptations:
• Millions of migratory birds breed in the tundra in the summer; food is
abundant in the form of plants, mollusks, worms and especially
insects
• Caribou in N. America and reindeer in N. Europe also migrate to the
tundra in the summer to breed
• Hunters like wolves prey on caribou, deer, moose, lemmings, mice and
rabbits
Tundra
Animal Adaptations:
• Rodents burrow
underground in the winter
to survive
• Arctic foxes and rabbits
have fur that changes from
brown in the summer to
white in the winter for
camouflage
• Snowy owl also is white
• The musk-ox has a dense
shaggy coat to help it stay
warm.
Tundra
Threats to the Tundra:
• Tundra is one of the most
fragile biomes on the planet
• The food chains are simple
and easily disrupted
• Because the weather is so
extreme, the land is easily
damaged and slow to recover
• Until recently, these areas
were undisturbed by humans,
but oil has been found in some
tundra areas and oil drilling
has a huge negative impact on
the ecosystem
Freshwater Ecosystems
• Freshwater ecosystems
include:
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Lakes
Ponds
Rivers
Streams
wetlands
Freshwater Ecosystems
• Lakes and Ponds
– In the shallow areas close to the shores of lakes and ponds,
aquatic life is diverse and abundant; this area is known as the
littoral zone
– Further from shore, the open water that gets enough sunlight for
photosynthesis is dominated by tiny plants and animals called
phytoplankton and zooplankton
– Some bodies of water have areas so deep there is little light for
photosynthesis. This is called the benthic zone; few fish are
adapted to this zone, but there are still plenty of bacteria
Freshwater
• Plants and animals :
– Along the shore, plants
such as cattails and
reeds are rooted in mud,
– Deeper water contains
floating plants, such as
pond lilies
– Fish, birds, amphibians,
mollusks are all common
Freshwater
Wetlands:
• Areas of land that are
covered with water for
at least part of the year
– Marshes are wetlands
that contain non-woody
plants and shrubs
– Swamps are wetlands
that contain woody
plants and shrubs
Freshwater
• Wetlands are important to the environment:
– They are often breeding grounds for many types of
fish
– They provide homes for native and migratory animals
– Wetland vegetation traps carbon that would
otherwise be released as carbon dioxide
– Wetlands remove pollutants from the water by
filtering it through the soil
– They also help control flooding by giving excess water
a place to go
Rivers
• Most rivers originate
from snowmelt in
mountains. This water is
very cold, full of oxygen
and very fast flowing
• As it tumbles down the
mountain, a river
broadens, slows,
becomes warmer and
oxygen levels drop
Rivers
• Characteristics of rivers
vary with changes in the
land and climate
through which it flows
• Mosses are common on
rocks near rivers, birds,
amphibians, mammals,
insects and of course
hundreds of species of
fish live in rivers
Marine Ecosystems
• The oceans of the world contain a wide variety of plant
and animal communities
• Types of organisms present in marine ecosystems
depends on the temperature, the amount of sunlight
and nutrients that are available
Estuaries
• An estuary is an
ecosystem in which fresh
water from rivers mixes
with salt water from the
ocean
• These waters have a lot of
nutrients for animals and
plants to grow
• There is a lot of sunlight
• Typical organisms here
are: oysters, clams,
dolphins, manatees,
seals, and plants
Estuaries
• The number one threat to
estuaries is pollution.
• Many boats use these
estuaries as points to
enter a river from the
ocean, or enter the ocean
from a river… there is a
lot of boat traffic and
pollution including:
waste, garbage, chemical
runoff, industrial waste
and sewage
Coral Reefs
• Coral reefs are
limestone islands in the
sea that are built by
coral animals
• Thousands of species of
plants and animals live
in their cracks and
crevices, making coral
reefs among the most
diverse ecosystems on
earth
Coral Reefs
• Corals can live only in
warm, salt water where
there is enough light for
photosynthesis
• Coral reefs are found in
shallow, topical seas.
• Only the outer layer of a
reef contains living corals,
which build their rock
homes with the help of
photosynthetic algae
Coral Reefs
• Animals: because of
their convoluted shape,
coral reefs provide
habitats for a
magnificent variety of
tropical fish, as well as
snails, clams and
sponges. There are also
many predators like
moray eels, sharks and
groupers.
Coral Reef
• Threats to coral reefs– Global climate change is affecting
the reefs since they are very
sensitive to temperature changes
– Muddy water and pollution kill
the algae in the area and corals
lose their food source
– Oil spills, sewage, pesticide
runoff are all affecting corals
– Human presence, boating, ship
anchors, divers are all damaging
the reefs
The Open Ocean
• The ocean covers nearly ¾ of the earth’s surface
• Although the ocean is HUGE, plants can only grow where
there are nutrients and enough sunlight for
photosynthesis
• As a result, most of the life in the ocean is concentrated in
shallow water around the edges of the continents
The Open Ocean
• In the open ocean,
sunlight only penetrates
the surface layers
where phytoplankton
grow if there are
enough nutrients, as a
result the open ocean is
the least productive of
all ecosystems
Ocean Depths
• Shallow Ocean
Waters- fish are
particularly abundant
in coastal zones,
where a rich nutrient
supply washes from
the land
• Deep Ocean Waters- no light
reaches these waters, so
photosynthesis cannot occur
in this area. Most of the life
here depends on food that
drifts down from above. Some
fish have huge jaws that
enable them to swallow large
particles of food. Other
animals of this area have lures
that give off light to attract
prey.
Ocean Depths
• The depths of the ocean are always dark and most of the food
consists of dead organisms that fall from the surface called
“marine snow”
• There are some producers near hydrothermal vents that make
food from chemosynthesis
• There is no photosynthetic organisms in the deep ocean and
almost all organisms in the deep are consumers
Plants in the Ocean
• Flowering plants are
mostly absent from the
ocean, except rarely
around the edges near
land
• Food for herbivores in
the open ocean is
provided by
phytoplankton
(photosynthetic
microscopic organisms)
Animals in the Ocean
• The sea’s smallest
herbivores are zooplankton
living with the
phytoplankton they eat
• Many open ocean fish have
sleek, tapered shapes for
moving though dense water
• Deep ocean fish often have
bioluminescence
• Whales, dolphins and other
marine mammals
communicate with songs,
clicks and barks… often
using echolocation
Threats to the Ocean
• Although oceans are huge, they
are becoming steadily more
polluted by boats (especially
cruise ships) and land activities
that cause pollution in the rivers
that runoff into the oceans
• The pacific garbage patch is a
floating island of garbage the size
of Texas that is causing huge
environmental issues in the
ocean
• Overfishing and net fishing are
causing populations of marine life
to get dangerously low. Many
turtles, whales and dolphins are
caught in fish nets and die.
Polar Ecosystems
• Ice covered polar caps
at the north and south
poles can be considered
marine ecosystems
because nearly all food
is provided by
phytoplankton in the
ocean.
Polar Ecosystems
• South Pole: lies on the
continent of Antarctica,
where it is covered with
a permanent icecap
that only melts around
the edges of the
continent in the
summer
• North Pole: lies in the
Arctic ocean, much of
which is frozen into a
huge iceberg
throughout the year,
with smaller icebergs
drifting around the
edges
The Arctic
• The Arctic Ocean is
relatively shallow, so its
waters are rich in nutrients
from the surrounding
landmasses and it supports
a large plankton population.
There fore there is a rich
diversity of fish, which live
in the open water and
under the ice. In open
waters whales and ocean
birds prey on the fish. Seals
are also present and the top
predator of the Arctic is the
polar bear
The Antarctic
• The Antarctic is the only
continent never colonized by
humans. It is governed by an
international commission and
is used mainly for research on
the unusual animals that live
there.
• Even during the summer, only
a few plants grow at the rocky
edges of the continent.
• Most food comes from
plankton. This provides food
for large numbers of fish,
whales and birds… especially
penguins. Many species of
penguins breed on Antarctica
Threats to Polar Ecosystems
• Both the Arctic and the
Antarctic contain reserves of
minerals and oil, whose
extraction would disrupt these
largely untouched ecosystems
• Conservationists want the
Antarctic to be made into a
wildlife refuge so that this
unique ecosystem can be
preserved
• Tourism, especially pollution
and garbage is difficult to
dispose of in a climate that is
too cold for decay to happen,
it just stays there.