Though the climatic conditions of the taiga biome are not favorable for plant life, certain plants thrive well in these regions.
Conifer trees are very common in the taiga biome. They release chemicals called terpenes, which have a pleasant smell. In large amounts, these chemicals form a bluish haze in the atmosphere. It is said that terpenes thicken clouds, which in turn results in cooling of the Earth!
The taiga/boreal forest is the largest among the terrestrial biomes in the world, and stretches over North America and Eurasia. The taiga biome amounts to around 30% of the world’s forest cover. A major part of the taiga is located in Canada and Russia. It is characterized by long and cold winters and short summers. Certain regions have a comparatively longer summer, and a warm and humid weather. Even the soil is thin, acidic, rocky, and infertile.
Though the Taiga biome is characterized by coniferous forests, some deciduous trees are also found in certain regions. While it is difficult for most of the plant species to survive in the taiga biome, those which are found in the region are well-adapted to these climatic conditions.
Adaptations of Plants in the Taiga Biome
The habitat of a biome is determined by the climatic conditions of the place. Although the taiga biome does not offer favorable conditions for plant and animal life, these regions are not barren. There are some plant and animal species that are adapted to the conditions of the taiga. Most of the taiga animals, like snowshoe rabbits and black bear, have a thick fur to protect themselves from the cold weather. Some of them hibernate during winters. Even the plants have some amazing adaptations.
Taiga plant life is much less diverse, as compared to the rainforests. Coniferous trees comprise a major part of the plant life in the taiga biome. They include pines, spruces, larches, and firs. These trees share have some special features that help them survive in the taiga.
Trees are Conical, and Grow in Large Groups
Most of the coniferous trees grow in a conical shape, with drooping branches. This prevents accumulation of snow on their branches. The snow that falls on the tree slides off easily, so that the branches do not break. Sometimes, the branches bend down due to snow buildup. If such branches come in contact with soil, they may develop roots and grow into new plants, which are totally identical to the parent plant. This method is termed layering.
Layering is one of the reasons why these trees grow close to one another. Coniferous trees are seen in large groups growing very tall and close. This is also said to be an adaptation that protects them from wind and cold.
Trees Are Evergreen With Needle-like Leaves
The needle-like leaves of coniferous trees are long, thin, and waxy. Unlike the broad leaves of deciduous trees, these needles do not lose much water through evaporation. They conserve heat during winter, and shed snow easily. Except tamarack, other coniferous trees in the taiga biome are evergreen, and do not shed their leaves. Trees like spruce may retain their leaves for around 15 years. This is to conserve energy, which is required for growing new leaves after shedding.
Coniferous trees shed their leaves on a regular basis, but they shed only a few leaves at a time, and the loss is unnoticeable. In short, these trees have leaves throughout the year, and they can start photosynthesis, as soon as they receive sunlight. It is also said that the dark green color of the leaves enables the trees to fasten the process of photosynthesis, by absorbing sunlight at a faster rate. However, tamarack trees shed their needles during fall to avoid water loss during winter.
Trees have a Shallow Root System, and Undergo Winter Hardening
The soil being thin and rocky, most of the coniferous trees have a shallow root system. It is difficult for the roots to grow deeper, as the soil beneath the surface is frozen. The roots spread wide so as to provide anchorage, and to absorb moisture and nutrients from a larger area.
During winters, coniferous trees undergo a process called hardening, to survive the freezing temperature. They become tolerant to very low temperatures. If the trees are exposed to such temperatures, before they harden, it may cause frostbite, which in turn can damage or kill them.
Trees are in a Mutually Beneficial Relationship with Mycorrhizal Fungi
Though coniferous trees can make their own food through photosynthesis, they face a dearth of nutrients. The fallen pine needles on the ground do not decompose easily. The white, thread-like mycorrhizal fungi that grow on the roots of coniferous trees help in decomposing pine needles. Thus the trees get enough nutrients for photosynthesis. In return, they provide food to these fungi. In short, coniferous trees and mycorrhizal fungi share a mutually beneficial relationship.
Benefit from Forest Fires!
Forest fires are common in the taiga biome. While major fires destroy most of the coniferous trees, minor ones may not cause much damage. However, these trees are adapted to the fire in different ways. One such adaptation is the thick bark. Some of them, like the black spruce and jack pine have a special adaptation. They produce cones on the top branches that are located far from the ground. The fire provides suitable conditions for these cones to open and disperse seeds.
Even some types of fungi depend on wildfires for releasing their spores. As wildfires burn down the thick canopy, sunlight falls on the ground, thereby triggering germination of grasses.
Deciduous Trees Shed Leaves During Fall
The taiga biome has deciduous trees in some regions where the winter temperature is not very low. They include birch, aspen, rowan, alder, balsam poplar, etc. These trees shed leaves during fall and regrow them during spring. Apart from preventing water loss during winter, such shedding reduces the risk of snow buildup and breaking of branches.
Parasitic Plants Derive Nutrition from Mycorrhizal Fungi
Mycorrhizal fungi and coniferous trees share a mutually beneficial relationship. But, there are certain plants that are parasitic on these fungi. They include the ghost plant (Indian pipe plant), pinedrops, and pinesap.
The ghost plant is white, without any chlorophyll. They grow in the dark understory of the forest, and are often found at the base of photosynthetic coniferous trees. The roots of these plants extract nutrition from the mycorrhizal fungi.
The pinesap plant and the ghost plant belong to the same genus. The pine sap too is dependent on the mycorrhizal fungi for food.
Though the pinedrops plant is from a different genus, the method of deriving nutrition is the same as the ghost plant, by extracting nutrition from the mycorrhizal fungi.
When it comes to the plants and trees in the taiga biome, you may identify two patterns of vegetation. The southern regions are dense with trees, and are characterized by a closed canopy. Even shrubs and flowering plants are found in clearings. Some types of berries are also seen in the southern regions. In these regions, the ground is covered with moss, especially peat moss. The northern parts have very few trees, with drought-resistant lichens covering the ground.
The taiga biome is spread over continents and countries. Though coniferous trees are prominent in this biome, some types of deciduous trees, shrubs, flowering plants, grass, etc. are also seen. However, the tree species may vary from one region to another. Different species of the same genus may grow in different regions. All these plants and trees are adapted to the specific climatic conditions of the biome.