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Week 11 · When Habitats Change

Thursday

A new plant moves in
// Move, adjust or decline
⏱ about 15 min

Thursday: A New Plant Moves In

Rocket crouches by the fence. "This vine was not here in spring. Now it covers the whole corner!"

Raven lifts a leaf with a pencil. The flowers underneath are shaded and small.

"It is taking the light," she says. "The plants that were here are shrinking."

Nova hovers above the tangle. "A new plant is a habitat change too," she says. "Who wins and who loses?"

Plants compete for the same things

Plants need light, water, air and space. In one yard, there is only so much of each.

When a new plant arrives, it uses some of the light, water and space.

Some new plants grow slowly and fit in. Others spread fast and take over.

A fast-spreading plant can shade out the plants below it. Shaded plants get less light and grow less.

When the old plants shrink, animals lose out too. The ones that ate them or hid in them lose food and shelter.

So a new plant can change the whole corner, not just its own patch.

Not every newcomer is a problem

Some new plants help. A flower that insects visit can add food to a yard.

A native plant has grown in your region for a very long time.

Local insects and birds already know how to use native plants for food and shelter.

A plant from far away may spread fast because nothing local eats it.

Scientists ask two questions about a newcomer. Does it spread fast? Do local animals use it?

Kind of newcomerWhat it doesWho winsWho loses
a native flower someone plantsadds food that local insects already useinsects, and the birds that eat themalmost no one
a fast-spreading vine from far awaycovers and shades other plantsthe vineshaded plants and the animals that used them
a shade tree someone plantsadds shade and nest spots over timeshade-loving plants and nesting birdssun-loving plants under it
WHO WINS, WHO LOSES?
  • Read the question.
  • Tap your answer.
A fast-spreading vine covers the flowers in a corner. Who loses?
What is a native plant?
Why can a plant from far away spread so fast?
Plants compete for light, water, air and ____.
A plant that has grown in a region for ages is a ____ plant.
A plant that shades out others takes their ____.
StatementTrue or false?
Every new plant is bad for a habitat.?
A fast-spreading plant can shade out the plants below it.?
Local insects already know how to use native plants.?
Plants do not need space.?
WHY THIS EXERCISEA newcomer can help or harm. It depends on how fast it spreads and who can use it.
HOW A VINE CHANGES A CORNER
  • ?The shaded flowers grow less.
  • ?Insects that used the flowers lose food and move or decline.
  • ?A new vine starts growing by the fence.
  • ?It spreads and shades the flowers below it.
WHY THIS EXERCISEA change to plants becomes a change for the animals that depended on them.
Try it
With a grown-up, find a plant that is spreading. A vine, a patch of ground cover or a weed will do.
Look under or next to it. Are other plants smaller or missing there?
Count the kinds of plants in the spreading patch. Then count the kinds in a patch beside it.
Safety first
Stay with your grown-up. Look with your eyes and use a pencil to lift leaves, not your fingers.
Some plants itch or sting. Do not pull or taste any plant.
Wash your hands when you are done.
Draw the fence corner in spring and now. Show the vine and the flowers under it.

You judged a newcomer fairly! Tomorrow we flip the question: what is one change that helps?

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