Ambitexto

Fall leaves were yellow all summer. You just couldn't see it.

• The green covers the yellow; in the fall, the tree takes the green apart to save its nitrogen.
• The reds are new: the leaf makes them from trapped sugar, weeks before it falls.
• At least 89 kinds of North American trees turn red. In all of Europe, only 24.

The forest is not dying. It is moving out of its leaves.

Words for the text

pigment

A natural material that gives a thing its color.

chlorophyll

The green pigment in leaves. It catches energy from the sun.

carotenoids

Yellow and orange pigments. Carrots have them.

anthocyanins

Red and purple pigments. Red apples have them.

nitrogen

A thing a tree needs to grow. Leaves have a lot of it.

The opening of the text

Yellow all summer

Pick up a yellow leaf in October. It seems new, but it is not. The yellow was in the leaf all summer. You did not see it, because the green covered it. So first, a simple question. Why is a leaf green?

A leaf is like a small factory. It makes sugar for the tree from sunlight, water and air. To catch the energy of the sun, it uses a green pigment. Its name is chlorophyll.