Small male cones make pollen. Wind wafts pollen through the air in yellow clouds to the larger, harder female cones, where it fertilizes the egg. After a year or so the fertilized egg becomes a winged seed, ready to be carried away by the wind. In the colder parts of the world there are vast areas of coniferous forest - especially in Canada and Siberia, where the Boreal forests or taiga extend for thousands of kilometres. Forests like these contain a mixture of trees, and include spruce, pine, fir and larch.
Coniferous forests tend to be dense and dark, with few other plants growing beneath the trees.
In slightly warmer areas, there used to be huge areas of broad-leaved temperate woodland, but much has been cut down. Where they do survive, broad-leaved woodlands are usually more varied than coniferous forests, containing oak, ash, chestnut, beech, maple, sycamore, elm, alder and hickory. Most, though, are dominated by either beech or oak. Broad-leaved woods are not so dense as coniferous forests, and many plants can be found growing beneath the trees. Coniferous forests tend to be dense and dark, especially where dominated by spruce, allowing few other plants to grow.