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Learning Activity

Edges, Where the (Inter)Action Is



Art form
writing, drawing or painting
Art, Science, Social Studies
grade levels
You will need
writing materials, art materials
variable, one hour to project level


This activity explores the ways and places where things join:

where land joins water,
where water joins air, and
where living creatures both green and animal join with all of these.

Edges are where the action is.

In ecology, we call this action the “edge effect.”

The places where things connect are exciting, because the edges between things are busy with life--and with death.

• Living things are also dashing across the edges, and back again to home.

• Edges are where a great deal of energy transfer takes place.

• Lots of eating and hunting on the edges. Edges contain more kinds of lives.

When we attend to the connections living things make at the edges, we wake to Nature at its most exciting.

The Activity

Discuss boundaries.

We usually think of boundaries as ways to mark what is ours, or ways to keep things out or to keep things in.

• In nature, boundaries, or interfaces, are the places where things connect, where things face each other, push against each other, or blend and blur into each other.

Discuss and List: Develop the concept of edge by discussing the examples of edge and interface below, then have the class extend the list.

• The place where each person “interfaces” with the world is his skin—the boundary, or edge, between our selves and the rest of the earth.

• The edge between a tree and the rest of Earth is its bark.
• Animal skins (like ours) are permeable membranes rather than an impervious barrier.

• Edges between field and woods, with their concentration of birds and animals, with their great diversity of plants.

• Edges between day and night—the powerful energy of dusk and daybreak:

• when the frogs sing at dusk,
• when the birds sing at dawn,
• when humans sink toward dream or swim up from it,
• when many animals are most active in feeding
(they are called ‘crepuscular’ or twilight creatures)

• Edges where water meets air:

• the surface of a pond or lake, with their
• concentration of insects, with
• swallows and flycatchers swooping down on them from the air,
• fish jumping up at them from the water,
• kingfisher and tern diving from air into water after the fish.

• the vast surface of ocean

• where sunlight feeds plankton and begins ocean food chains
• where seabirds bob on the surface and dive for fish
• where gannets plummet from air like spears and dive deep.
• where the young of countless marine species are either nurtured or become food.

Consider Interfaces in Time.

• Think of a fossil as an interface between times;
• think of moments in your life which were interfaces in Time.

• moments between child and teen?

Consider topographic features as edges:

• see watershed “divides” as edges.
• See“treeline” on a mountain as an edge.

As you climb a mountain, you pass through ecosystems based on altitude & temperature. At the base is forest, higher is dwarfed or scrub forest, which becomes wet meadows, which become dry tundra, then bare rock. These are essentialy the same changes you pass through as you travel north toward the pole, through North America

Think of the edges between human society and the natural world.

• The edge of town, between country and city.
• The long edges where a river passes through a town.
• The edge between wilderness and road.
• The edge between the window screen and mosquitoes.
• The edge between street and park, or street and garden.

If you are skilled at solving jigsaw puzzles, you know the smart place to start is by finding the edges, the straight sided pieces that are the boundary of the scene. It’s often the same with solving the puzzles of Nature.


Turn Edges into Art


Discover an edge in nature, or between nature and the human world, where things interface and the energy is high.

• Observe and record in words and/or drawing in your Journal.
list energy transfers (eating) at this edge. Note the time for each transfer.
• Observe this edge at different times of day. List the differences?

Example: Watch the surface of a pond or stream, where it meets the air and where it meets the land. Notice the high numbers of insects flying at dusk and dawn—which means there will be many birds feeding on them at those times.

Draw a picture of the most exciting thing you observed at your edge, or write a detailed description.

Write a story describing significant moments in one 8 hour period in the life of one edge.


When people act cooperatively we see edge effects happening:

• the energy and action is best when we play off each other,
build on each other.
When people connect in cooperation, energy and action result.

Have students list or otherwise recall some moments when they ‘reached across’ the edges between people and gave energy to other or received energy from an other.

This might be a family moment, a sports moment, a choir moment, a moment of sorrow or grief

• Choose one such moment and paint how it felt.
• Write Journal entries about those moments.

Student Source Sheet: Edges

Interface means a place where things join, or connect to each other.

An Interface is a surface forming the common boundary between adjacent solids, spaces, etc.
So an interface is a kind of boundary.
An interface is a kind of edge between two kinds of places.
An example of an interface, or edge in nature is the surface of a pond, where air and water meet.

is the scientific name for an edge between living communities.
Eco- means life, and -tone means tension.

So an edge in ecology is a place of life tension.

At the ecotones we find the greatest species diversity and the most biological density.
More growing, more hunting, more eating, more energy transfer!


Diurnal, nocturnal and crepuscular are three fancy words used in the life sciences. Their meanings are simple.

Diurnal means ‘active in daylight.’

Nocturnal means ‘active at night.’

Crepuscular means ‘most active at dusk and dawn.’

creatures like the twilights between day and night.


Living systems have boundaries. Living organisms are open systems in the sense that they take and excrete energy and matter. … but they are also enclosed within a hierarchy of internal boundaries. As we move in towards the Earth from space, first we see the atmospheric boundary that encloses Gaiia; then the borders of an ecosystem such as the forests; then the skin or bark of living animals and plants; further in are the cell membranes; and finally the nucleus of the cell and its DNA.

— James Lovelock, The Ages of Gaia






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