How are gymnosperms important? 30 September 2007 Chris Campbell, University of Maine The world and human civilization would be very different if there were no pines, redwoods, spruces, and other gymnosperms. These trees form extensive forests in many cooler and colder regions of the world. These forests provide lumber for millions of homes, wood for many other uses, most of our paper, and habitat for many species of wildlife. These forests improve the air we breathe, generating oxygen and sequestering carbon dioxide. Gymnosperms are probably the leading source of timber in the world, and their wood is used in many ways. The so-called soft pines, such as eastern and western white pine, are excellent for paneling and furniture. In Colonial times, the King of England claimed all large eastern white pines for potential use as masts for ships of the English navy. Other pines, cedars, and Douglas fir are excellent for the structural parts of wooden homes, and gymnosperm wood is used for telephone poles, decking, boats, shingles, pencils, natural moth-proofing for closets, soundboards of stringed instruments (such as violins), and numerous other purposes. Cedars, pines, spruces, hemlocks, junipers, yews, and many other gymnosperms are valuable ornamentals. It is surprising that some prized gymnosperm ornamentals have much smaller geographic ranges than they had at some time in past and appear to be on the brink of extinction in the wild. The maidenhair tree (ginkgo), for example, is extremely rare in nature and has persisted in the world for thousands of years mostly as ornamentals near religious buildings in eastern Asia. The dawn redwood was thought to be a fossil until it was seen in a remote valley in China in the 1940’s. Despite their tenuous status in nature, Ginkgo and the dawn redwood both grow very well as ornamentals along the streets of large cities. Gymnosperms are also fascinating organisms. They include the tallest (redwoods), most massive (giant sequoias), and longest living trees (bristlecone pines). They are an old group that dominated the earth during the time of dinosaurs, long before the origin of flowering plants such as lilies, roses, and oaks. Gymnosperm genomes are huge, in some cases at least ten times the size of the human genome, and organized in unique ways. Despite their prominence in the world, we still have a lot to learn about these fascinating plants. For instance, we are uncertain about many of the evolutionary or phylogenetic relationships among the approximately 1100 species of living gymnosperms. We are also unclear about fundamental relationships among these living gymnosperms and extinct groups of gymnosperms plus the other major group of seed plants, the flowering plants. A clearer view of the phylogeny of seed plants is critical to our knowledge and appreciation of these important organisms.