Taiga or Boreal Forest
The Taiga or Boreal forest stretches far across the northern hemisphere. It is the largest land ecosystem on Earth.
17% of Earth's land
The Taiga produces vast quantities of oxygen, which refreshes the atmosphere of the entire globe.
Surviving here can be difficult.
1600km from the north pole, the northernmost part of the Taiga, dominated by conifer trees, has to endure Arctic conditions.
Limited daylight, particularly in winter, means trees struggle to absorb light for photosynthesis.
Temperatures as low as -70°C mean the ground is usually frozen.
Dead vegetation takes a long time to decay, meaning the soil is not very fertile.
And, despite an annual rainfall of 38 to 50cm, most water is frozen as ice.
Little unfrozen water
These factors mean that the growing season lasts just one month a year in the Taiga, so trees grow slowly and remain fairly small.
Coniferous trees keep their needles year-round, so they can begin photosynthesis as soon as the season changes.
As water is scarce, they protect their needles, which store water, by filling them with resin. This makes the needles taste bitter, so few animals eat them.
But while the Taiga may appear to be a silent world of only trees, it supports a surprising diversity of animal life.
Moose and black bears roam between the trees, the cross-bill feeds on pine cones, and elusive creatures such as wolverine and lynx also live in this harsh environment.
Parts of the Taiga are threatened by logging, mining, and oil and gas production, but some areas are so remote that the vast landscape remains untouched, even by man.