Salient Features of Taiga 1) Winters are very long and snowy, temperature reaching a low of about 6oC. Summers are very brief with the average temperature of 20oC. Taiga, the world's largest land biome, has a harsh continental climate with a very large temperature range between seasons classified as "Cfc""Dfc" or "Dfb" in the Köppen climate classification scheme. Aside from the tundra and permanent ice caps, it is the coldest biome on Earth. High latitudes mean that for much of the year the sun does not rise far above the horizon. Winters last at least 5?6 months, with average temperatures below freezing. Temperatures vary from ?54°C to 27°C (-65°F to 80°F) throughout the whole year, with eight or more months of temperatures averaging below 10 °C (50°F). The summers, while short, are generally warm and humid. In general, taiga grows to the south of the 10 °C July isotherm, but occasionally as far north as the 9 °C July isotherm.[2] The southern limit is more variable, depending on rainfall; taiga may be replaced by open steppe woodland south of the 15 °C July isotherm where rainfall is very low, but more typically extends south to the 18 °C July isotherm, and locally where rainfall is higher (notably in eastern Siberia and adjacent northern Manchuria) south to the 20 °C July isotherm. In these warmer areas, the taiga has higher species diversity with more warmth-loving species such as Korean Pine, Jezo Spruce and Manchurian Fir, and merges gradually into mixed temperate forest, or more locally (on the Pacific Ocean coasts of North America and Asia) into coniferous temperate rainforests.
The taiga experiences relatively low precipitation throughout the year (200?750 mm annually), primarily as rain during the summer months, but also as fog and snow; as evaporation is also low for most of the year, precipitation exceeds evaporation and is sufficient for the dense vegetation growth. Snow may remain on the ground for as long as nine months in the northernmost extensions of the taiga ecozone.[3]
Much of the area currently classified as taiga was recently glaciated. As the glaciers receded, they left depressions in the topography that have since filled with water, creating lakes and bogs (especially muskeg soil), found throughout the Taiga. [edit] Soils
Taiga soil tends to be young and nutrient-poor; it lacks the deep, organically-enriched profile present in temperate deciduous forests.[4] The thinness of the soil is due largely to the cold, which hinders the development of soil and the ease with which plants can use its nutrients.[4] 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, creating spodosol.[5] Since the soil is acidic due to the falling pine needles, the forest floor has only lichens and some mosses growing on it.
2) Precipitation occurs as both rainfall and snow. Rainfall varies from 10 - 35 cm in dry areas and upto 100 cm in wet areas. 3) Summer is mild and provides a short growing period (of about 60 - 150 days).
4) Soils are thin, acidic and poor in humus as the fallen needles (coniferous leaves) form a thick zone on the surface and decomposition / decay is very slow due to low temperature and poor growth of decomposers. 5) Very little light reaches the forest floor.
Flora a) Climax vegetation consists of needle leaved evergreen trees. Dominant species are - spruce, pine, fir, cedar, birch, etc which are able to tolerate wide fluctuations in temperature, light and soil conditions.
b) Forest is stratified into an evergreen tree stratum (40 - 70 feet high), a short shrub stratum (2 - 4 feet high), low herbaceous plants (less than 4 feet) and forest floor covered with moss and lichen layer. c) Shrubs are shade resistant and herbs usually show broad leaves.
d) Few varieties of ferns, mosses and lichens grow on trees and shrubs under humid conditions. Fauna Rich and varied animal life is found in taiga as there is abundance of food. Animals include:
i) mammals like mouse, deer, musk rat, pine mouse, porcupine, elks, rabbits, squirrels, etc. ii) insectivorous birds like grouse, jay crossbill, etc.
iii) reptiles such as lizards and snakes. iv) reindeer and caribou migrated from tundra biome is seen during winter months.
Total productivity of taiga biome is estimated to be 2000 kcal/m2/year.
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