Plants need to photosynthesize in order to grow. To photosynthesize, plants require sunlight. Because of this, plants often have to compete with each other for sunlight. This is why plants such as trees strive to grow tall.

Different species of plants have adapted into different light conditions. Plants such as pine and lingonberry are light plants. They require a lot of sunlight in order to grow. Their small leaves are resistant to light and heat due to their thick structure and their protective wax layers.

In contrast, plants such as wood sorrel and chickweed wintergreen are shade plants. Their leaves are thin, broad, and located on the top of the plant's stem. They have adapted into conditions where sunlight is scarce, such as the forest floor.


Shade plants have thin, broad leaves. Leaves of wood sorrel and liverleaf.

Plants have also adapted to inhabit different layers of the forest.

• The tree layer is the highest layer of vegetation. It comprises of all coniferous trees, broadleaf trees, and shrubs over two meters tall.
• The shrub layer consists of shrubs and tree saplings that are under two meters tall. Species such as juniper and willow often occupy the shrub layer of a forest.
• The layer consisting of short sprigs and grasses is known as the the field layer. The common species of the field layer include blueberry, heather, wavy hair-grass, and goldenrod. 
• The lowest layer of vegetation in a forest is the ground layer. It consists mainly of different mosses and lichens.

In young forests, the amount of shrub and field layer vegetation is high. In older forest, especially broadleaf forests, the trees provide so much shade that lower levels of vegetation are very scarce.