The Taiga and the Boreal regions situated amidst the Arctic circle and the 50ºN including the places like Alaska, Canada, China, Scandinavia, and Russia constitute the evergreen coniferous forests. These regions have a typical climatic condition characterized by the following:
Winter climate- Lasting for about 6-7 months, the winters appear usually very dark and quite freezing with temperatures ranging from -65ºF to 30ºF.
Summer climate- Lasting for about shorter durations, the summer climates are characterized by warm temperatures and also small amounts of rains with temperatures ranging from 30ºF – 70ºF.
Precipitation- Usually falling in the summer season, the annual precipitation ranges from about 30-84 cm.
The Boreal or the Taiga forests are often referred to as the Northern Eurasian Coniferous Forests. These two words usually denote the total circumpolar coniferous forest including the bogs, lakes, and also the rivers. The coniferous forests are also found on the mountain ranges in most of the regions of the world. The trees that are dominant in the coniferous forests include the firs, pines, larches, and spruces. All the trees have similar heights, shapes, and usually create a consistent stand along with the lower shrub and herb layers including the lichens, liverworts, and mosses covering the surface of the forest.
Ecological Distribution:
The evergreen temperate coniferous forests are predominant in coastal regions that constitute milder winter climates and substantial rainfall or inshore where the climate is dry or in the montane regions. Most of the members of the cedar, redwood, pine, and fir dwell in these forests. The understory is known to comprise vast varieties of species of herbs and shrubs. The temperate evergreen coniferous forests retain maximum ranges of the biomass in any of the ecosystems and are usually prominent for the large proportionate trees in the regions of the temperate rainforests. Seven regions from all over the world are known to accommodate these temperate rain/coniferous forests including the Eastern Black Sea and Northeast Atlantic regions including Scotland, Ireland and Iceland, Northwest Pacific, Valdivia forests in the Southwestern parts of South America, Southwestern Japan, and Rain forests in New Zealand and also Tasmania.
Characteristics:
In terms of its structure, the evergreen coniferous forests have a simple structure comprising of two different layers, namely the Overstory and the Understory. However, certain forests might allow the growth of shrub layers. The pine forests are known to maintain ground layers of herbs that are usually subjugated by the forbs and grasses that contribute to the wildfires significant in the ecological systems. On the contrary, the humid climatic conditions observed in the temperate rain forests usually support the predominance of utilizing forbs and ferns.
The forest communities are largely subjugated by larger trees like the Redwood-Sequoia sempervirens, Eucalyptus regnans, Sequoiadendron giganteaum, and others. It is not a usual phenomenon in the ecological systems and is observed in the regions of Southwestern South America, Western regions of North America, Australasian areas like Southeastern Australia or the Northern regions of New Zealand. The ecoregions of the Klamath- Siskiyou present in the Western regions of North America are known to embrace distinct and rare congregations.
Biodiversity patterns- Mosttree species and also larger vertebrate species are known to be distributed all over substantial native endemism and also diversity is present in certain invertebrate ecoregions, the lichens, and understory plants specifically in the rain forests or uncommon soils. They might display distinct varieties of invertebrate animals or the herbaceous plants, altitudinal adaptation, and selection but it is not usually noticeable when compared to the tropical regions.
Minimum requirements- The majority of the coniferous forests comprise variable disturbance episodes like the epizootics, fire, and windthrow, yet the extremities are characteristical of uniform size and occurrence to create small-sized areas of the natural forests having restricted values of conservation. Most of the species are largely specific in late-successional forests.
Sensitivity to disturbance- The bigger carnivorous animals are largely susceptible to the activities of human beings comprising of the lower intense hunting processes, especially the late-successional species; The late-successional members and their characteristics restore at slower rates. Most of the temperate coniferous forests need intermittent fires to sustain the processes of succession and also most of the species, exotic species, are known to have larger and highly significant influences on the communities of the natural forests.
