Not only can trees survive a cold winter, they actually need the cold before they can grow again in the spring. Each species requires a certain number of cold days during winter. The tree can only start to grow and flower again in spring once it has met its cold requirement. This helps protect the tree from flowering too early in the spring when cold weather could kill the blossoms.
When the winter days feel warmer but the nights are still freezing cold, sometimes cracks appear in trees with thin bark. The bark and inner wood expand a little in the warm sun, especially on the south or west side of the tree. When the sun stops shining, the bark cools quickly and contracts faster than the inner wood. This can cause a crack. The colder the night, the bigger the crack. On really cold nights, you may hear a loud bang when a tree cracks.
Providing an excellent introduction to the subject of trees, this book covers a wide variety of related topics: the parts of a tree, kinds of trees, leaf shapes, photosynthesis, respiration, how a tree grows, how to determine a tree’s age, pollination and the development of fruit, trees through the seasons, how to plant a tree, endangered trees, and the many uses of trees, not the least of which is providing homes for many different kinds of animals. Text boxes, entitled, “Strange Trees”, add interesting trivia, one example of which is that a 2000-year-old giant sequoia, nicknamed “General Sherman”, is as tall as a 23-storey building. There is a tree-watching chart that helps readers to examine trees more closely and a map of Canada and the United States which identifies various types of forest regions and the kinds of trees that grow there.
Though younger readers in the target audience will need assistance in reading some of the vocabulary, an abundance of lovely, colorful drawings, rendered in watercolour and gouache, will sustain their interest and help them to understand the concepts. A table of contents, a glossary and an index are included. Though the pronunciation of a few of the words in the glossary appears in the main body of the text, it would have been beneficial, especially for younger readers, to provide the pronunciation for more of the glossary entries.
Definitely worthy of purchase, Trees will not only serve as an excellent primer, but it will also give readers a sense of the tremendous importance of trees.
Gail Hamilton, a former teacher-librarian, lives in Winnipeg, Manitoba.