Trees: adaptations in woods and forests

Summary

This chapter is about plants which grow in forests. One of the major trends in land plant evolution has been the evolution of trees. Most groups of land plants have given rise to tree species. There is a great diversity of both living and extinct forms. The evolution of secondary growth by a lateral meristem, enabling a tree to increase in girth as it grows in height, was a crucial early event in land plant evolution. The two groups with efficient secondary growth, the conifers and the dicotyledonous angiospems, dominate the forests of today. Trees are the naturally dominant form in all parts of the world except cold environments at high latitudes or high altitudes, and very dry environments. They have been removed from large areas by the activities of large herbivores and man. A large number of species of epiphytes have evolved to exploit trees as their habitat.