Taiga & Boreal Forests

Taiga, sometimes called the "coniferous forest," is dominated by conifers but has low plant diversity. It is the largest biome in the world based on landmass. This biome may be geologically recent, only forming within the last 12,000 years, replacing the mammoth steppe. The word "taiga" is Russian for forest.

Climate

A climate that is snowy, cold, with 4 months of a growing season

Rainfall

20 - 185 cm/yr

Temperature

Average annual between -5° and 5°C

Regional Expressions

northern North America and northern Eurasia

Soil

Thin, nutrient-poor, and acidic (spodosols)
Spodosols are characterized by high acidity, and have a subsoil accumulation of organic matter, along with aluminum and iron oxides, called a spodic horizon.
Typically low in natural fertility (basic cations, Ca2+, Mg2+, and K+) and high in soil acidity (H+, Al3+), these soils require extensive inputs of lime and fertilizers to be agriculturally productive.

Flora

Cold-tolerant evergreen conifers
- Pine (Pinus), fir (Abies), and spruce (Picea) are common
Mosses and lichens are common as forest floor flora
A few deciduous angiosperms exist as forest edge and pioneer species (e.g. Populus)

Adaptations

Evergreen leaves
Reduced leaf area (See specialized leaves) such as needle-like leaves
Sunken stomata (See specialized leaves)
Hypodermis (See specialized leaves)
Deciduous leaves - a few angiosperms a deciduous in this biome (See specialized leaves)
Root suckers in some angiosperm trees

Above: A Whittaker Graph showing where the taiga occupies this abiotic space, based on precipitation and temperature

Evolution of the biome

The boreal forests dominated by conifers have been more common since the origin of the angiosperms in the Cretaceous, as many conifer taxa evolved to survive in higher latitudes and altitudes, away from angiosperm competition
Starting around 50 million years ago, the Earth has become progressively colder compared to the Mesozoic, and conifers became more prominent in higher latitudes and altitudes
During the Neogene, coniferous forests expand in many areas as the Earth became colder with glaciations
The taiga, in its current form, may have only formed within the last 12,000 years, replacing the Mammoth Steppe, after the extinction of the mammoth and other large herbivores

Additional Resources

Fire suppression and winter warming jointly drive dieback of natural Mongolian pine forests (Phys.org 1Dec2025)

└Anthropogenic fire suppression and climate change-driven winter warming inducing the dieback of natural Pinus sylvestris var. mongolica forests on sandy land (Song et al., 2025)

Making trees in fire-maintained forest less susceptible to drought (Phys.org 13Jun2025)

└Wilson & Hurteau (2025) Trees in Fire-Maintained Forests Have Similar Growth Responses to Drought, but Greater Stomatal Conductance Than Trees in Fire-Excluded Forests

Slowly dying trees impact forest recovery post-wildfires, according to study of 2020 fires (Phys.org 28May2025)

└Dyer et al. (2025) Post-fire delayed tree mortality in mesic coniferous forests reduces fire refugia and seed sources

Nordic studies show the significance of old-growth forests for biodiversity (Phys.org 27May2025)

└Nirhamo et al. (2025) Forest biodiversity in boreal Europe: Species richness and turnover among old-growth forests, managed forests and clearcut sites

How a worm perpetuated wildfires in northern (boreal) Minnesota (Phys.org 15May2025)
North American boreal forest holds 31% more trees than thought (Phys.org 13May2025)

└Xu et al. (2025) How many trees are there in the North American boreal forest?

The world’s boreal forests may be shrinking as climate change pushes them northward (3Nov2023 The Conversation)

Google Sites

Report abuse