The winters in this part of the world, with average temperatures below freezing, last six to eight months. Temperatures vary from −54 °C to 30 °C (-65 °F to 86 °F) throughout the whole year. The summers, while short, are generally warm. In large parts of this region, -20 °C would be a typical winter day temperature and 18 °C an average summer day. Snow may remain on the ground for as long as nine months.
Precipitation is low; rain does fall during the short summer, but mostly it's snow and fog, the latter coming from the thawing of the frozen Serpent Lake starting in late spring. Due to the fog, sunshine is not abundant in the boreal forest of the region, even during the long summer days, but there is enough moisture to sustain a dense forest growth.
The forest along the southern parts of the Serpent Lake consists of a mix of spruce, pines, birch, larches and tranteum trees (see below).
Due to the cold, the soil is thin and poor in nutrients. Fallen leaves and moss can remain on the forest floor for a long time in the cool, moist climate, which limits their organic contribution to the soil. Acids from evergreen needles further leach the soil, sometimes creating areas that are almost sandy and excessively drained. In other parts of the region, only lichens join the moss. In forest clearings, herbs, berries, shrubs and wildflowers can be found, among them the infamous Stinkberry bushes (see below) and the dangerous Calathgar (see below). Twisted Treants are known to have clearings as their favorite spots in this area, and act as gardening guardians, occasionally gaining the powers of a druid to complement their natural abilities.
In the northern parts of the region, the closed canopied forest gives way to a more widely spaced lichen woodland, with diminished foliage on the windward side.
Periodic wildfires with return times of about 50 years clear out the tree canopies, allowing sunlight to invigorate new growth on the forest floor. For some species, wildfires are a necessary part of the life cycle in the taiga; some have cones which only open to release their seed after a fire, dispersing their seeds onto the newly cleared ground.
The tranteum tree, an evergreen, is endemic in this part of the world, its wood much sought of by elves who like to use it for bows with an especially long range. A masterwork bow out of its wood and built by an elven master has its range increment heightened by 10'. Because the sun is low in the horizon for most of the year, it is difficult for plants to generate energy from photosynthesis. Tantreum trees do not lose their leaves seasonally and are able to photosynthesize with their older leaves in late winter and spring when light is good but temperatures are still too low for new growth to commence. The ground freezes during the winter months and plant roots are unable to absorb water, so the Tantreum tree has found a unique way to store warm water beneath its bark. If released by needy creatures, the warm water is enough for one medium humanoid for a day and also heals two points of nonlethal damage from cold, but the Tantreum tree will wither and die as a result. Elven druids of the Northlands are known to get very angry should this happen.
Stinkberries, which can be found in forest clearings, emit an acidic smell even before plucked, but more so once removed from the thorny twigs of the infamous Stinkberry bushes. They can be crushed easily and the resulting tar-like substance pasted on the skin, which lowers Charisma-based skill checks by 2 versus creatures with a sense of smell. They also turn the skin slightly paler. The first two days of wearing Stinkberry paste the wearer is nauseated also, then she gets used to the smell. Orcs and Half-Orcs are immune against this nauseating side effect for unknown reasons. The upside of the Stinkberries is that they drive away insects of all kinds, which is a blessing in the summer months, and also drives away dweomercats and ahlinni (see below). Nonetheless, the usage of stinkberry paste is forbidden in the villages Drak'kal and Sunglor, but not in Torrent, which regularly leads to lots of comments among the Klavekians from those three villages. The contents of an average stinkberry bush is enough to paste two medium humans. The effects last for seven days.
Calathgar have blossom the size of shields and shocking blue petals, which make them easily recognize- and avoidable even for those with a poor Knowledge (nature) check. They smell of vinegar and some druids speculate that they are able to feed upon the acids so common in the ground. Be that as it may, the plant is carnivorous also and obviously needs more than acids to thrive.
The cold winters and short summers make the taiga a challenging habitat for reptiles and amphibians, which depend on environmental conditions to regulate their body temperatures, and there are only a few species in this part of the world. Some hibernate underground in winter.
The boreal forest is home to a number of large herbivorous mammals, such as moose, reindeers, elks and caribous. There is also a range of rodent species including beavers, squirrels and some species of hares. Some larger mammals, such as bears, eat heartily during the summer in order to gain weight, and then go into hibernation during the winter. Other animals have adapted layers of fur or feathers to insulate them from the cold.
The biggest herbivores in the region are the mammoth, the mastodon, the woolly rhino and its even bigger cousin, the elasmotherium. Unlike to the nearby plains, where they roam in vast herds, the forest contains but singles or families of those large animals.
Predators like owls, eagles, foxes and weasels feed on rodents and are themselves sometimes hunted by the bigger predators. Those include the great cats like the lynx, snow leopards, cave lions, smilodons and white tigers and also by the wolverines, including their bearlike dire wolverine cousins. The wolves are a close second among the most variant hunters, ranging from normal wolves and terror wolves up to the dreaded dire wolves and winter wolves. Notable is also another great cat, the unique and stealthy missing lynx, the forest drake and the many-colored Ahlinni, a flightless predatory bird.
Omnivores like bears, dire bears (cavebears) and raccoons are present also.
Insects have also carved their niche in the northern forest, and not only the swarms of flying pests that fill the summer airs. Monstrous insects in the north are the feared white-and-silver, cold generating gelid beetles, which come in small and large variants, the giant tarantula spider and the dreaded weaverworm, which many sages count under Aberrations also.
Rumors speak of a green dragon in the forest, or a white one in variants, and also a few linnorms, but if such large predators are indeed living in the regions no one has survived an encounter with them yet. No rumor are the large taiga giants who roam the forest to hunt the megafauna.
Surprisingly Fey are rare in the boreal forest at the Serpent Lake, with the Mimi the sole exception. Sage speculate that they were driven out by their brethren in the Dark Wood further north, but why this may have happened, if at all, nobody knows or talks about. The Mimi are gathered in tribes of up to 80 fey and could be a big force in such numbers if they ever chose to.
A few Kitsune families are known to live in the forest, but they give the Mimi tribes a wide berth.
Some people count the dweomercats as well as the fey wolverines as faeries. While the fey wolverine is more undisputed in this category and even has a fitting name, the dweomercat is a creature of the first world. How it got to the Klavekian lands at all is the stuff of many discussions.
Another creature of dubious origin is the smoke haunt who attacks woodcutters and others emerging from their campfire. A local tale, sung by the skalds of the three villages at the Serpent Tail River, tell a story linking it to the fey, but if this is fictitious or based on facts is up to discussion.