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Interactions within

Ecosystems

Ecosystems

An ecosystem is a place on Earth where living

things interact with other living things as well

as non-living things.

Example: A human

Biotic: Humans, dogs, birds, trees, wheat,

grass, flowers, moss, squirrels, cows…

Abiotic: Rocks, water, metal, cars, oil…

Which of the following are examples of

ecosystems?

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Science Journals

Reflect on your experiences relating to ecosystems

1. I was surprised to learn….

2. I found it interesting that…

3. I wonder…

Biotic and Abiotic In science – the term biotic refers to living things

Living things are those that can reproduce themselves

Ex: Bacteria

Ex: Humans

Ex: Tree

Ex: Micro-organisms that we can’t see but still exist

In science – the term abiotic refers to non-living things

These are all necessary components to life, but they cannot create

more of themselves

Ex: Water

Ex: Rocks

Ex: Air

Ex: Metal

Biotic and Abiotic

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Human Needs

The Ecosystem of a School

Go on a school walk in groups of 3 – remember to be quiet

in the hallways

Identify all biotic and abiotic components that you can.

As a group:

1. Provide a sketch of the school ecosystem

2. Provide a list of both biotic and abiotic elements within the

ecosystem

3. Provide a paragraph explaining how the various elements

interact within the school ecosystem.

Ecological Succession

Ecological succession is the natural and gradual change in

the type of species that live in an area.

Succession can be primary or secondary

The gradual replacement of one plant community by

another through natural processes over time (this is

predictable)

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Ecological Succession: Primary Succession

Begins in a place without any soil

Sides of volcanoes

Landslides

Flooding

First, lichens that do not need soil to survive grow on rocks

Next, mosses grow to hold newly made soil

These species are known as pioneer species

Ecological Succession: Pioneer Species Lichen growing on a rock

Lichen break down rock to

form soil

Moss growing after lichen

Low, growing moss plants

trap moisture and prevent

soil erosion

Ecological Succession: Primary Succession

Soil starts to form as lichens and the forces of weather and

erosion help break down rocks into smaller pieces.

When lichens die, they decompose adding small amounts of

organic matter to the rock to make soil

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Ecological Succession: Primary Succession

Simple plants like mosses and ferns can grow in

the new soil.

Ecological Succession: Primary Succession

The simple plants die, adding more organic material

(nutrients to the soil)

The soil layer thickens, and grasses, wildflowers and

other plants begin to take over

These plants die, and they add more nutrients to the soil.

Shrubs and trees can survive now

Ecological Succession: Primary Succession

Insects, small birds and mammals have begun to move into

the area

What was once bare rock, now supports a variety of life.

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Ecological Succession:

Secondary Succession

Begins in a place that already has soil and was once

the home of living organisms

Occurs faster and has different pioneer species than

primary succession

Ex: after a forest fire

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Ecological Succession: Climax Community

A stable group of plants and animals that is the end

result of the succession process

Does not always mean big trees

Grasses in prairies

Cacti in deserts

Ecological Succession

Consider the following questions:

1. What are some ways in which new plants move to an

area?

2. What are some reasons animals move to a new area?

3. What naturally occurring event can start the process of

succession all over again?

4. What happens if the event from #3 is prevented from

taking place?

5. What are some ways in which humans prevent or

accelerate the process of succession?

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Human Impact

Humans can impact ecosystems in a variety of ways, both

positively and negatively

We will examine a couple examples more in-depth.

Bambi II

Listen carefully to the story

that Bambi shares with his

daughter, Bambina.

Identify ways in which

humans impact deer

Game – Keep Score

If you are a “runner”, your goal is to collect the bean bags

If you are a “stopper”, you need to use only the balls in

your hoop to throw at the runners

The indicated areas are “home-free” – cannot throw at

the runners there

If a “stopper” hits a runner, the runner needs to stop for 3

seconds and the stopper gets to quickly collect the runner’s

bean bags

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Habitat Fragmentation

Habitat fragmentation is the separation of a

landscape into various land uses

This results in numerous small habitat patches

leftover for use by wildlife.

Habitat Fragmentation:

Why is it a Problem?

The small habitat patches often do not provide adequate food and cover resources for survival.

This can result in an increased risk of starvation or death by predation, if the animal has to venture beyond the cover of the patch to find new food resources.

Habitat Fragmentation:

What Causes Fragmentation to Occur?

Human activities, such as…

Urbanization,

Large and small scale hydroelectric

facilities,

Multilane highways,

Railways,

Transportation infrastructure (roads), and

Various industrial activities

These all have impacts on wildlife habitats

through physical removal of lands and

dangers through vehicles, illegal hunting

and encroachment

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Habitat Fragmentation:

Fragmentation can be Small-Scale too!

Hiking,

Off-road vehicles,

Other recreational pursuits…

Snowmobiling,

Skiing,

Golfing…

May seem environmentally benign, but they also result in

widespread damage, especially if wildlife populations are

stressed already.

Habitat Fragmentation:

Consequences

Divided highways, logging and recreational access roads cut off

usable portions of some animals home ranges and create

barriers to movement.

Habitat Fragmentation: What Could We

Do to Help Reduce Fragmentation?

Block off land that has been found to have high

species diversity

Block off land that has high species population

Stricter forestry policies for logging practices

Curtail urban sprawl

Minimize roads by sharing them

If foresters and hydro-electric companies share the same

roads, there is less need to build extra roads, resulting in

reduced fragmentation

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Human Impact

From the provided articles, write down the following:

Title of article:

Type of ecosystem being affected:

Causes of change within the ecosystem:

Does the change to the ecosystem have a positive or

negative impact? Support your answer with points from

the article.

Compare with 2 other classmates – what were their

articles about?

Sustainable Development

It is a way of making

decisions that balances

the needs of today

without sacrificing the

ability of future

generations to meet

their own needs.

Sustainable development is an approach to daily decisions

that integrates probable consequences to the environment,

the economy, and human health and well-being.

Factors in the Management and

Preservation of Ecosystems

From the articles, identify the…

Environmental,

Social,

Economic

Factors that should be considered in the

management and preservation of ecosystems.

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Assignment

Choose one of the topics we were presented with

from the articles

Propose a course of action to protect the habitat

and/or particular organism within an ecosystem

Activism

As a class, identify an issue related to an

endangered organism and/or habitat for class

exploration.

Design a course of action to become involved in

an issue, while recognizing that the principles of

sustainable development need to come into play.