Organism adaptations in the Taiga biome

Adaptations of Organisms in the Taiga Biome

Taiga or Boreal Forest

Taiga or Boreal Forest (also Northern Coniferous Forest) cover about 11% of the Earth's land surface, or one third of its total forested area (about 1.5 billion hectares/3.7 billion acres). It occurs in the Northern hemisphere, in a circumpolar band, running though Canada, Scandinavia, Russia, China, Mongolia, the Korea Peninsula, and Northern Japan. Although taiga is the Russian name, it can be used interchangeably with "boreal forest" for the biome as a whole. The word boreal comes from the Greek for north wind, an appropriate name for a forest in which so much of life is geared to meeting the challenging winter.

In Canada, the boreal stretches from south to north across the country's midsection for as much as 2,000 kilometers, mingling on its southern edge with the hardwood forests, aspen parkland and prairie of more southern areas and gradually fading out through tree-dotted taiga and muskeg as it meets the treeless tundra at its northern extreme.

The boreal touches every province and territory of Canada, from the spruce-lined "ponds" of the Island of Newfoundland to the narrow mountain valleys of remote northern British Columbia and Southern Yukon. It sweeps across the land in an arc of deep moss-carpeted forest, fast-flowing rivers, black lakes and wetlands of almost every description. It is home to hundreds of species of songbirds in summer that feed and nest in its insect-rich forests and to water birds that race to its lakes and wetlands before the ice is even fully melted every spring.

The boreal is also a place where the natural food web remains unbroken, where large carnivores such as wolves, bears, lynx and cougar still leave their mark on the entire ecosystem. Reclusive species like woodland caribou and pine marten have largely retreated to these forests away from the landscape-altering logging, mining and industry of more southern regions.

To some eyes, the boreal is a uniform expanse of spruce and muskeg. But these are eyes that have not looked closely enough. Like other natural systems, the boreal contains a wide diversity of species, forest types and ecosystems with the added benefit that, particularly in more northern areas, these natural systems have remained untouched by industrial activities.

The boreal can range from large unbroken expanses of black spruce or jack pine that are ideally adapted to powerful natural forces like wildfire and wind to highly diverse forests with a wide mixture of ages, species, sizes and habitats. The beauty of the boreal can be found in small and delicate orchids growing in the deep shade of a spruce forest, the intricate lichens carpeting the forest floor or in the blaze of fireweed in a burnt-over stand of jack pine, a tree that has been called "a natural roman candle" because of its tendency to literally explode in flames, releasing thousands of tiny seeds onto soils left warm and blackened by the passing fire.

Adapting to survive cold and deep snow is critical for all boreal creatures whether it's the retractable hoof pads developed by woodland caribou or the thick coat and wide paws of a timber wolf. Boreal creatures also have to be able to travel long distances in search of food and prey, which means large habitat areas are critical for their long-term survival.

If there is one word that describes the boreal it is "big." Stretching across millions of square kilometers, this truly is Canada's Big Wild.

Characteristics of Boreal Forest

Boreal Forest is one of the largest biomes in the world. Winters are long, cold, and severe in boreal forests. The landscape is dotted with patchy areas of permafrost, as well as numerous lakes, ponds, rivers, and bogs. However, the majority of the land mass is covered with evergreen forests that consist primarily of conifer (cone bearing) trees such as black and white spruces and eastern larch. Compared to the size of this biome, there are relatively few tree species represented.

Boreal forests have a very short growing season during the warmer summer months. Little precipitation falls throughout the year, so inhabiting plants are well adapted to surviving in drought conditions. These forests are predominated by coniferous trees, which have needle-shaped leaves that have minimal surface area to prevent excessive water loss. As these needles fall from the trees, the forest floor becomes littered. As these needles decompose, they add an acidic quality to the soil, which naturally has a very low nutrient content. These two traits, along with a cold environment, short growing season, sporadic permafrost, and slow decomposition contribute to the overall low productivity of boreal forests.

The boreal forest also is prone to wildfires. Many trees have adapted to this by growing thick bark, which can protect a tree from a mild fire.

These high latitude and altitude forests provide habitat for a few large mammal species such as moose, wolves, caribou, and bears. Numerous smaller species such as rodents, rabbits, lynx, and mink also inhabit these forests.

Despite the remote locations and often inhospitable environment of boreal forests, they have long been a source of valuable resources. The boreal forest serves as a major source of industrial wood and wood fiber, including softwood timber and pulpwood. The low productivity rate in these forests leads to a slow rate of forest regeneration.

Boreal forests are also rich in metal ores (including iron ore and gold); as well as coal, gas, and oil. The logging and mining industries led to the development of settlements, roads, and industrial complexes. These industrial complexes (pulp and paper mills, mines, and ore smelting plants) have contributed to problems with air pollution in both Canada and Russia.

Wolverine

The Taiga Biome is populated with special animals that all have techniques of keeping warm and dry or away from the harsh coldness of the Taiga. One animal of the Taiga is the wolverine.

The wolverine nicknames include "Devil bear" and "Wood bear." Native Americans called it carcajou, a French corruption of a Native American word meaning Evil Spirit or Mountain Devil. Native Americans believed the Wolverine possess magical powers. Wolverines were considered as the last phantom of the wilderness, master of the forest, trickster hero and the magical link between the material and spirits word. They also praised the wolverine because of the following traits, which are standing your ground, fierceness, elusiveness, cleverness, strength and endurance.

Wolverine scientific name "gulo" means "Skunk Bear" or "glutton" because of its habit of attacking any prey it happens to meet. The wolverine is meat eating animal, or carnivore. Its body length can get up to 87 centimeters as an adult and weigh about 45 lbs. It looks sort of like a bear, with short legs, but it is the largest member of the family Mustelidae which includes river otters, sea otters, marten, weasel and mink. The wolverine is powerfully built and is well adapted to living in the cold. It has very strong jaws that can bite through frozen meat and bone. Its head is wide and kind of rounded, with small eyes and small round ears. Its paws are very large with long claws. The wolverine's fur is thick and a glossy dark brown. The thick coat of brown fur protects it from the freezing cold temperatures.

It is known for its physical strength and sharp, accurate hunting skills. Wolverines have a very keen sense of smell that helps it locate food. A wolverine will eat almost anything. Sometimes it may hunt moose or a caribou but it can't eat it all at once so it sprays it with musk (a strong smelling fluid from anal gland under its tail) and buries it. It feeds mostly on rodents and rabbits, birds and bird eggs, fish, reptiles, carrion, and sometimes berries. The only one thing they won't eat, a porcupine. This is because it may swallow quills and die. Its habitat is in the sparse boreal forests in the northern half of taiga. it's also spread across the arctic tundra. The wolverine also lives near the tree line on the mountains of the western United States. The wolverine being a solitary animal will depend its territory against any other wolverine that dares to encroach on its space. It warns other of its presence by discharging musk. It is a good climber and often rests in trees. Because it is so large, the wolverine does not have a single nest site, but several scattered throughout its range.

During breeding season the males usually stay close to the female, but they prefer to travel alone. The wolverine also declares a temporary truce with other wolverines during the summer mating season. Courtship by the male includes dragging the female around by the scruff of her neck. The pair may mate several times, for several hours at a time. To help the male keep an erection, a bone, called the baculum, stiffens his penis. The vigorous mating induces the female to produce eggs.

In many mammals the fertilized eggs implant in the uterus soon after mating, and then start to develop. The female wolverine delays implantation; the egg cells float in the uterus for some time attaching to the uterus wall. Delayed implantation means that the young can be born at the right time, from January to April, regardless of when mating takes place. The female produces one litter every two or three years. She digs out a den in a snowdrift, in a tree hollow, or under a rock, where she has her young, called kittens. Two or three kittens are born each year. The kits are born furry and their eyes are closed. The kittens feed only from their mother for two or three weeks. During this time she rarely leaves them, feeding on food she has stored. Later the mother brings food to the den, but the kittens are eight to ten weeks old before they are weaned. They reach adult size by early winter but may stay with their mother until they are old enough to reproduce.

The wolverines need a large home territory of about 200 square miles. They need lots of shelters in rock crevices and among boulders to hole up during bad weather or to escape predators. Its huge, flat feet and long claws make the wolverine an excellent climber. Their feet also act as snowshoes and keep them from sinking into deep snow.

The wolverine is a shy animal that tries to avoid contact with humans. Human settlements and low birth rates have decreased the wolverine populations in North America. Wolverines are considered a rare and vulnerable species.

Structural and Behavioral Adaptations

Wolverines are so mean and so clever that trappers and outdoorsmen have called them Mountain Devil. Wolverines will follow their prey anywhere. They will follow them into caves, over mountains and dark places. It will follow for days if it has to. The wolverine is very strong and mischievous. They have been known to steal food. Wolverines are very brave they will fight almost anything.

A wolverine also has very small webs on its feet that help it swim. It has shorter fur and thicker skin in the winter that helps it keep warm. It hibernates for 2 months then stays awake for the rest of the time. It has sharp claws for digging.

Physiological Adaptation

One physiological adaptation of wolverine is their ability to response to seasonal change. Wolverines also have techniques of keeping warm and dry or away from the harsh coldness of the Taiga.

Water Vole

The water vole Arvicola terrestris, also known as the Northern water vole, is a semi-aquatic mammal that resembles a rat. In fact, water voles have often been mistermed, "water rats." It is also the largest and most famous of the British voles. Water voles have a short hair-covered tail, a blunt, rounded nose, and a small chubby face with small ears. They have a rich chestnut-brown coat, but individuals in Scotland often have black fur. The fur traps air that provides thermal insulation when swimming and they also possess flaps of skin in the ear that prevent water from entering. The body length is 12-20 cm and the weight is 150-300g.

They feed mainly on grasses and other plants near the water. At times, they will also consume fruits, bulbs, twigs, buds and roots. In Europe, when there is enough food to last water voles a long time, water vole "plagues" can take place. Water voles eat ravenously, destroying entire fields of grass and leaving the fields full of burrows, during these plagues. Voles may also eat insects, mollusks and small fish.

The water vole is active by day and night, and spends most of its time eating. It moves through grasses, sedges, willow shoots and other waterside plants, grasping the stems in its forepaws, tearing at them and biting out the best parts. A trail of discarded fragments and stumps is left behind. The water vole is, of course, a very good swimmer, paddling with all four legs, blunt nose held clear of the water. Its short dense undercoat, covered by the long outer fur, keeps the vole warm and dry which helps them to survive in a boreal forest.

Water voles have a few natural predators including herons, owls, pike, mink and otters. When chased underwater by an enemy, such as an otter, the vole kicks up a cloud of mud that acts like a smokescreen, giving the vole a chance to escape via one of its underwater burrow entrances.

Water voles generally live in burrows in the banks of slow-flowing watercourses where there is a high level of plant cover to provide them with shelter and food. They can also live in the banks of canals, ditches and ponds, and will make woven nests about the size of a small football in reeds and sedges. The burrow complex usually has at least one submerged entrance. The water vole is a very shy creature, requiring a great deal of cover around its burrows and over its runs. They will dive into the water if danger threatens. It is active during the day, unlike the rat which is largely nocturnal, but is rarely seen. Dawn and dusk are the best time to catch a glimpse of a water vole. Often the first clue that a water vole is present nearby is the 'plop' sound of them disappearing into the water from amongst the vegetation as you pass by. They have, however, become sufficiently tame in certain areas to steal the bait from fishermen's bait boxes.

This species lives for 2-3 years. The breeding season for water voles is from late March until early October, during which time all adults will hold discrete territories along the bank. Males hold relatively large territories which will encompass the territories of several females. Each territory is marked by a series of latrine sites, where the animals regularly leave their droppings and stamp to leave their scent.

The droppings are about 1cm long, regularly shapes and rounded at the ends. They are normally green in color and relatively odorless. When broken open they are clearly green inside. Another definitive sign of the water vole is a grazed 'lawn' often seen around the outside of a burrow on top of a bank. This is due to heavily pregnant females not venturing far from the burrows and simply popping their heads out and grazing around the edge of the burrow.

During the winter months, no breeding occurs and the animals no longer hold territories. They also become less active. This makes it more difficult to accurately determine whether water voles are present or not. The signs of rats will, however, still be visible and so care must be taken not to not identify a bank as being inhabited just by rats when water voles are present as well.

Structural and Behavioral Adaptations

The male water vole has a range of over 425 feet of water bank; the female somewhat less. To mark its territory, the male rakes its hind feet over its flank gland and pushes out a secretion that it then stamps into the ground with its hind feet. Water voles generally do not form large colonies. Those that live on dry land may form groups consisting of the adult pair and two generations of young. Water voles will fight if they are overcrowded, uttering high, shrill squeaks.

Water voles are expert swimmers, but are not particularly specialized for a life in the water, unlike beavers and otters but when chased underwater by an enemy such as this otter, they raised a cloud of mud that acts as a smoke screen.

Water voles also burrow into steep canal or riverside banks to form a complicated system of underground tunnels and nesting chambers. Intelligent voles construct their burrows on several levels to minimize the risk of flooding and at least one entrance will be below the water level for a fast escape if necessary. Water vole spotters should look out for closely grazed 'lawn' areas, often covered with neat piles of chopped grass, which are seen around burrow entrances.

Physiological Adaptation

One physiological adaptation of water vole is reproduction which may carry on through the summer into early winter, depending on the weather. In winter, a female, her daughter and unrelated males share a communal nest which is made of woven grass stems and usually below ground in a burrow, but they do not hibernate.

American Pika

American pikas are tailless, have somewhat circular ears, are grayish to brown and are about the size of guinea pig. Their total length is 6.8 to 8.4 inches (170-210 mm); their weight is 5.3 to 6.2 ounces (150-175 grams). Like all lagomorphs, they have double upper incisors but the front pair is large and functional and the very small posterior pair is peg-like. Pikas have hair on their feet, an adaptation that gives them great traction as they scurry about rocks. Pikas are recognizable behaviorally. They dart about on talus slopes and you may hear their distinct, shrill whistle call or short "mew" that sounds like an insolent cat. Often that call will give their presence even though you cannot sight them.