Conifers

Conifers are the most successful of the gymnosperms, the group of plants whose seeds are not enclosed in an ovary. They first emerged during the Carboniferous period, about 300 million years ago and they continue to thrive to this day. There are around 570 species and they cover large areas of the temperate and subpolar regions. Their reproductive structures are well protected, in most cases, by the cones that give the group their name. The other characteristic for which conifers are well known, needle-like foliage, is not, however, found in all conifers. The conifer group includes monkey puzzle trees of South America and Australasia; the redwoods of China and the USA; and the Pinaceae, the most successful conifer family which includes around 300 species of pines, larches, spruces, firs and cedars. The members of this group have narrow, needle-like leaves that are ideally suited to resist drought, fire and frost. They have therefore long dominated the colder parts of the northern temperate zones. This family has probably benefited from the recent (in geological terms) cooling and drying of the world's climate; it has helped them to spread even further over the northern hemisphere. Boreal forests of fir, pine, spruce and larch cover huge areas of the subarctic, while evergreen forests of pines and cedars cover much of the drier temperate areas, including the Mediterranean. The larches are among the few deciduous conifers and inhabit even the inhospitable plains of northeast Siberia where not even tough conifer needles could survive the cold dry winters.