Transcript Communities and Ecosystems

Communities and Ecosystems
1.01 Describe and compare several common ecosystems
(communities of organisms and their interaction
with the environment).
Community
• A community is the interaction of all living
things in an area.
• Plants and animals are living things. Living
things are sometimes called organisms.
Staying closer together helps organisms
better interact to survive. Microbes, like
fungi and bacteria, are also living things
that are part of a community.
• Communities are made up of different
populations of living things. A population
is a group of the same type of organism
existing in an area. Your neighborhood is
made up of a population of humans. It is
also made up of a population of crows. Or,
let’s say mice, or perhaps grasshoppers.
You see, there are hundreds of different
populations that make up a single
community. Each population relates with
other populations in some way to form the
larger community.
How is a Community Different
from an Ecosystem?
• A community is not the same thing as an
ecosystem. An ecosystem is all the living
things in an area AND their habitat. A
habitat is a physical place where an
organism lives; its shelter. Both living and
non-living things make up an ecosystem.
Plants, animals, water, soil, sunlight and
air are all part of an ecosystem.
• Ecosystems are everywhere. They can be
as big as an ocean or as small as a
puddle. Organisms are biotic factors in
ecosystems. Non-living parts of an
ecosystem are abiotic factors. Anytime
biotic factors exchange matter or energy
with abiotic factors—it is an ecosystem.
Remember, an ecosystem is a system.
• Just as ecosystems vary in size, so do
habitats. Smaller or less mobile living
things have smaller habitats compared to
larger active organisms. Think about this
for a second, a squirrel’s habitat is usually
not much larger than a single square mile.
But a black bear, on the other hand, can
have a very large habitat covering many
miles. An earthworm’s habitat would be
smaller than a squirrel’s.
• Ecosystems must meet the needs of
organisms. Ecosystems most provide
enough space, food and water for
organisms. Many factors in an ecosystem
can affect an organism’s survival. If there
isn’t the right type of soil, or if the
temperature is too hot or cold, certain
organisms will not exist in that ecosystem.
If an ecosystem cannot meet the needs of
an organism, the organism will move or
die.
Some Common Ecosystems
• Let’s look at a few examples of some
common ecosystems.
Tundra
• The tundra is located near the north and south
poles. Rainfall is light. Summer temperatures
average only 1ºC (34ºF). The land in the tundra
has poor soils that are almost always frozen.
There are many lakes, ponds and bogs. Grasses
are present but only a very few small trees grow
there. The plants that grow there are mosses
and lichens. Animals living in the tundra are
reindeer, caribou, polar bears, arctic wolves,
foxes, hares, lemmings, birds and insects.
Temperate Forest
• The deciduous, or temperate, forest has
variations in rainfall, but in general, the rainfall is
medium. The average summer temperature is
around 24ºC (75ºF). It has large and small trees
that are broad-leaved with foliage that changes
color in autumn. Trees such as oak, maple, red
bud, tulip popular, pine and dogwood grow in
this ecosystem. The animals found here are
squirrels, deer, foxes, and bears. The state of
North Carolina has some temperate forest
ecosystems.
Grasslands
• In general, the rainfall is low or very seasonal.
The average summer temperature is 20ºC
(68ºF). As the name implies, the dominant form
of plant life found in this ecosystem is grass.
Other types of non-woody plants can be found
here. Plants like buffalo grass, sunflower,
coneflowers, goldenrods, and clover thrive here.
There are large herbivores on the savannas
such as bison, pronghorn antelope, and zebras,
as well as smaller ones such as burrowing
rodents and prairie dogs.
Tropical Forest
• The tropical rain forests have abundant rainfall
and are very humid. The average summer
temperature is 25ºC (77ºF). The trees are very
tall with dense canopies. The floor of the tropical
rain forest does not get much sunlight, but it
does keep a fairly constant temperature. There
are many species of both the plants and animals
found in the tropical forest. Plants like vines,
ferns, large and small trees and orchids live in
the rainforest. Animals like orangutans, insects,
sloths and jaguars also live in the rainforest.
Desert
• Deserts get little rain and have extreme
temperature fluctuations. The average
summer temperature is 30ºC (86ºF). There
is not much grass in the desert, but what is
there is very drought resistant. Other
plants, like sage-brush, mesquite and
cacti, have also adapted to desert
conditions. Animals common to the desert
are the kangaroo rat, snakes, lizards,
some birds, spiders and insects.
Aquatic Ecosystems
• Aquatic ecosystems include freshwater
areas, estuaries and marine areas all of
which are determined by the saltiness of
the water. Amount of light, oxygen, and the
temperature are also important abiotic
(non-living) factors of aquatic systems.
Freshwater
• Freshwater ecosystems consist of
streams, rivers, lakes, marshes, and
swamps. All have low salt levels. Fresh
water is an important nutrient to land
plants and animals. It is also a major part
of the water cycle. Freshwater ecosystems
are found in areas with different
temperatures and support a wide variety of
animal and plant life.
Estuary
• An estuary is a place where fresh and salt water
meet in a coastal area. The salinity level in an
estuary fluctuates, but it is generally not as high
as in the ocean ecosystems. The water is partly
surrounded by land with access to open ocean
and rivers. Estuaries contain salt marshes and
swampy areas and are biological diverse. This is
because the tides circulate nutrients while
removing wastes. There are many different
types of unique plants and animals in estuaries.
Estuaries are important for removing many water
pollutants before emptying into the ocean.
Marine
• Marine ecosystems include the ocean
areas and seas. These waters have a very
high salt content. They are warmer and
have lots of sunlight near the surface of
the water but get colder and darker the
deeper the water gets. Coral reefs, tide
pools, beaches, and the ocean floor are
just a few examples of marine
ecosystems. An abundance of plants and
animals live in the ocean.
Review
1. What term best describes an ecostems?
A. connected
B. separate
C. large
D. small
2. Which of the following is an abiotic factor
in an ecosystem?
A. trees
B. bugs
C. sand
D. humans
3. Which abiotic factor separates marine
ecosystems from river ecosystems?
A. sunlight
B. salt
C. sand
D. algae
4. Which sentence describes a habitat?
A. Grass uses sunlight to grow.
B. A mole lives underground.
C. Bacteria break down dead plants.
D. Deer eat forest plants.
5. What is a community?
A. a group of organisms living together
B. an ecosystem
C. non-living parts of a habitat
D. living and non-living parts of a habitat
The End!!!