The coniferous forests of the Northern Continent represent the greatest expanse of uninterrupted forest in the world. Coniferous trees do well at high latitudes because they are evergreen, and photosynthesis can take place immediately conditions are right for growth without having first to produce leaves, as is the case with deciduous trees. In this way the conifers compensate for the short growing season, which is about 50 to 80 days depending on the latitude. Fruiting and reproduction are also in tune with the climate. Conifers, unlike deciduous trees, do not produce fruiting bodies that are pollinated and ripen within a single year. The fertilization of a female cone may take more than a year to complete, and as many as three more years may elapse before the cone matures and the seeds are ripe for dispersal.
The lack of leaf litter and the prevailing cold conditions which inhibit the natural decay of the forest's pine needle carpet - material that is slow to decompose in any case - results in only a thin underlying layer of topsoil and little or no undergrowth. The indigenous mammals are largely herbivorous and exist mainly on diets comprising mosses, pine needles, bark and seed cones. Insectivorous birds are rare compared with those that feed on cone-seeds and buds.
Throughout the region forest fires are not uncommon, usually occurring in spring, when the trees are low in sap. Large areas can be devastated at a time. Recolonization is firstly by deciduous trees such as birches, alders and rowans that are only later replaced by the climatic vegetation of spruce, larch, cedar or pine.
The conifer tree's typical tall, pointed shape is ideal for bearing the weight of the winter snowfall and allows the snow to be shed quickly when it melts in spring. Their surface-spreading root systems are perfectly adapted to the shallow soils that are characteristic of the habitat.
In the north of the region, where the underlying soil is frozen all year and is therefore impervious to water, there are many lakes, streams and bogs with their own localized flora of mosses and sedges. The forest is more open and blends into the neighboring tundra. Larger patches of tundra mosses and lichens appear on high ground. Near rivers in this transitional area the forest remains thick and extends far northwards along sheltered valleys into the tundra. At the southern edge of the coniferous belt, the conifers grade imperceptibly into deciduous woodland.
Throughout the world, smaller areas of coniferous forest are found outside their normal latitudinal extent, particularly on the slopes of mountains, where the altitude produces climatic conditions similar to those experienced near the poles.
During the rule of humanity the coniferous forests experienced considerable environmental damage, due mainly to clearance for agriculture and also in the course of commercial forestry. This effectively exposed large areas of land to the erosional effects of wind and rain, destroying the soil structure and consequently reducing its water-retention capacity. The coniferous forests took some time to recover from this damage, for the normal successive recolonization could not take place immediately.
The browsers are the largest animals living in the coniferous forest regions. They feed mainly on young twigs and needles in the summer and subsist on bark, mosses and lichens during the rest of the year.
As in all other habitats the animals of the coniferous forest fall into the familiar food chain pattern of predator and prey with the carnivorous animals forming the final link. Here, as in the temperate woodlands, the fiercest and commonest hunters are the predator rats. They hunt beneath the trees in small packs, tracking down the rabbuck and the hornhead, singling out the weak and elderly individuals and running them to exhaustion. The predator rats take it in turn to attack, savaging their prey with powerful front teeth. Hornheads have such powerful horns that, when they are the quarry, it is almost as dangerous for the hunter as it is for the hunted.
Throughout the Cenozoic the rodents were one of the most successful animal groups in the coniferous forests. Their powerful teeth enabled them to cope with the tough vegetable matter found there and their warm, furry coats helped them to retain body heat during hibernation. Most conifer forest rodents live on shoots, bark and the seeds found in cones. Many are ground dwellers and feed from the cones where they fall. Others are lightly built and agile enough to scramble along the branches to where the cones are actually growing.