Ecosystems

What effects do biotic and abiotic factors have on an

ecosystem?

Diane Gioia

Bell’s Crossing Elementary

What makes up an ecosystem?

• Ecosystem – all the living and nonliving parts of an environment

• Biotic factors – the living parts of an ecosystem

• Abiotic – the nonliving parts of an ecosystem

BrainPOP movie

An ECOSYSTEM is an interacting system of plant, animals, and humans and the surrounding environment. An

ecosystem contains living and non-living things that contribute to the

functioning of other organisms. An ecosystem is NOT just a collection of

organisms. It is a system of interactions and interrelationships.

An ecosystem can be as small as a puddle or a rotting log.

An ecosystem can

also be a whole forest or the planet.

Can you name some abiotic and biotic factors?

ABIOTIC• Rocks• Air• Temperature• Soil• sunlight

BIOTIC• Trees• Flowers• Cats• Dogs• you

Create a flip chart with 3 flips to display each of the upcoming

vocabulary words.

1. On the outside write each word and draw a picture of the word.

2. On the inside bottom flap write the definition.

3. On the top flap create a sentence with your new vocabulary word and draw a picture illustrating the word.

Populations

All members of one kind of organism

that live in a

particular area.

Communities

A group

Of different

Populations of organisms

Habitat

A place where an organism lives

• Ecology: Organisms in their Environment

(15 min)

What are the characteristics of different ecosystems?

There are many types of ecosystems, each with its own characteristics.

Differences in abiotic factors in ecosystems lead to differences in the living things there. Factors such as sunlight and precipitation affect how organisms adapt to these ecosystems.

Different Ecosystems

Terrestrial ecosystems – these are land based such as forests and grasslands

Aquatic ecosystems – these are water ecosystems

• Fresh water: ponds and lakes• Saltwater: oceans, estuaries, and

saltwater marshes

16 min.

2 min.

aquatic

3 min : marine

Deciduous Forests

• Deciduous forest ecosystems have trees such as

oaks, elms, and maples. These ecosystems are found in the eastern part of the United States, including South Carolina. These forests grow in moderately warm places where there is a lot of rain.

• The trees lose their leaves in the fall. Food and shelter are hard to find in the winter so, some animals hibernate.

Coniferous Forests

Coniferous forests are made up of mostly conifers, trees that have cones. These forests are found mostly in the northern part of the Northern Hemisphere.

Trees include spruces, hemlocks, pines, and firs.

Animals include moose, deer, caribou, wolves, bears, and elk.

The northernmost coniferous forests are called taiga.

Rainforests

Rain forests get large amounts of rain. Tropical rain forests are warm all year. These conditions enable large populations of many kinds of organisms to live there. Hawaii is the only state with tropical rain forests.

GrasslandsGrasslands are ecosystems in which grasses

are the main plant life. Grasslands have fertile soil and have few trees. These ecosystems do not receive much rain during the year, so trees do not grow well. These are found in the midwestern United States. Much of the grassland in the U.S. has been turned into farms causing some animals like bison to lose their habitat.

Estuaries and Salt Marshes

Estuaries are places where rivers flow into the ocean. Estuaries have water that is saltier than a river, but not as salty as the ocean.

Salt marshes are grassy wetlands at the edges of estuaries. South Carolina has many estuaries and salt marshes and is home to many living things such as fish, blue crabs, shrimp, and oysters.

Oceans

The ocean has many kinds of ecosystems. The oceans are so large that the conditions in one part of the ocean are very different from the conditions in another part of the ocean.

Some ocean ecosystems are close to land and receive more sunlight. In the deep sea, sunlight cannot reach the ocean floor and the ecosystems are quite different.

The deep-sea anglerfish has a body that glows in the dark. It has a rod that glows and dangles in front of its mouth which attracts prey.

Lakes and Ponds

Most lakes and ponds are freshwater ecosystems. The water in each of these ecosystems does not move much. Ponds are smaller than lakes. Ponds sometimes dry up during hot, dry summer weather. Because lakes are larger, they are usually permanent.

Lakes, ponds, pools – 10 min.

• World Biomes

How do organisms interact and depend on one another in an

ecosystem?A food chain shows how organisms get

their food. The first organism in a food chain is a producer; consumers or decomposers follow

   

Producer consumer decomposer

Most energy comes from the sun

• Plants, also called producers, convert energy from the sun into food through a process called photosynthesis.  

• Photosynthesis is a process which uses water, carbon dioxide, and sunlight energy to make sugars.  Plants do this in special cells called chloroplasts.  These are usually green because of a pigment called chlorophyll.  Most photosynthesis happens in a plant's leaves, which is why they are green.

• When an animal eats a plant, some of the energy gets passed from the plant to the animal.  A food web shows this passage of energy, by showing what animals can eat what, and who gets eaten by who

Consumers

Animals, fungi, and some kinds of microorganisms do not make their own food. Living things that cannot make their own food are consumers. Consumers get energy by eating other living things.

• Herbivores – eat only plants• Carnivores – eat only meat• Omnivores – eat both plants and

animals.

DecomposersDecomposers are bacteria, microorganisms, fungi or

other animals (termites and worms) that feed on decaying matter. These decomposers speed up the decaying process that releases nutrients back into the food chain for absorption by plants. They are Earth’s natural recyclers.

What would happen if a forest had no decomposers?

Plants would use up all the nutrients in the soil, and the ground would be covered in animal wastes and dead organisms.

Predators and Prey

Predators are animals that eat other animals. The animals they hunt and eat are called the prey.

Predators often have eyes that are in front of the head. This placement helps the animals judge how far away their prey is.

The eyes of prey are often on the side of its head. This placement allows the prey to avoid predators by seeing a wide area.

Parasites and Hosts

A parasite is an organism that feeds off another organism, called a host. Fleas, leeches, and ticks are parasites. Ticks bite their hosts. Then they take blood from their host for food. Unlike a predator, a parasite does not usually kill the animal it feeds on. If the host dies, the parasite loses its source of food.

Food Chains and Food WebsA food chain shows a single path that energy and

nutrients take through an ecosystem. Arrows in a food chain show how energy and nutrients move.

sun plants hare owl bacteria

A food web is a system of overlapping food chains. In a food web, energy and nutrients can flow through many branches and gives a better picture of the complex way that energy and nutrients move in an ecosystem.

What affects populations?

The number of living things that can live in any ecosystem is limited. A limiting factor is an environmental factor that determines how large a population can be.

The most common limiting factors are:• Water• Food• Space• shelter

Some factors that influence populations

Population Size

Shelter Availability•Climate change•Human intrusion•Natural events

Amount of Space•Overcrowding

•Change in

Competition for Food•Predators•Parasites•Disease

Water Availability•Pollution

•Climate/Weather

Population Increase

If there are more plants than usual in an area, populations of animals that eat that plant may increase. If one animal’s population increases, the population of animals that eat that animal might also increase.

Increases in population are not always good. Sometimes a population will grow too large for the environment to support.

Population Decrease

Other changes in limiting factors will cause a population to decrease. If the water supply in an area decreases, the population that needs water may decrease.

Then the population of animals that eat that animal could decrease too.