There are several kinds of trees. In tropical rainforests, where it is warm and wet all year, most trees are evergreen and keep their leaves the entire year.
Tropical rainforests are found near the Equator, where there is little difference between the seasons. In countries with a temperate (moderate) climate, deciduous, board-leaved trees shed their leaves in autumn. Losing leaves reduces evaporation. This helps the tree conserve energy and water when the ground water is frozen, and reduces damage by frost.
Trees can be identified by looking at such characteristics as bark, leaves, and flowers, and in autumn by their fruits and nuts, some of which are shown on the right. The size and shape of the trunk and branches can also help to identify a tree, and scientists record the tree’s girth by measuring the distance around the trunk at chest height. You can study trees in your backyard, a local park or the wood following the same checks. Choose an area of mixed woodland with many different trees. Always take an adult with you to keep you safe.
Field guide to local trees, note book, pen, colored pencil.
MEASURING A TREE'S HEIGHTYOU WILL NEED
Yardstick, l yd-long stick, felt-tipped pen.
MEASURING A TREE'S GIRTHYOU WILL NEED
Sticky tape, string, yardstick or tape measure, pen, notebook, colored pencil, graph paper, field guide.