Biomes: Tundra (1989)

[Music] [Music] [Music] a biome is a community of living things the vegetation that develops in a certain climate region and the animal life that has become adapted to it among the major biomes on Earth one of the most difficult for living things is the tundra the Arctic tundra forms a belt around the north polar regions of the world from the coniferous forests of Asia Europe and North America to the icy Arctic ocean temperatures in the tundra are low year round and the growing season is short less than 5 in of precipitation Falls each year mostly in the form of snow only one kind of large mammal lives year round in the tundra the musk ox a musk ox's massive body produces much heat and loses that heat slowly its layered fur is one of the best natural insulators found among mammals arctic foxes also grow layered fur their short ears and white coats also help reduce heat loss they can survive in the open at 40 below in tunnels under the snow that Lemmings build temperatures are never much below freezing [Music] Lemmings are the favorite food of foxes and most other Arctic predators and breed in large numbers some birds can also survive the winter cold of the tundra Willow tagin keep warm by roosting in snow Banks they feed on the tiny dwarf Willow one of the few Woody plants of the tundra the willow Tagan like the arctic fox turns white in winter this helps to hide the birds from predators as well as slowing their heat [Music] loss by April the days are getting longer but not until June does the temperature rise above freezing the shallow soil layer cracks as it thaws now the tundra is transformed into a vast water logged plain of ponds and marshes under this is a deep layer of soil that never thaws called the permafrost meltwater cannot drain through the permafrost and so it collects in countless ponds lakes and marshes no tall trees are found here because the permafrost prevents any deep roots from forming that trees need as spring continues the hours of day daylight increase until over much of the tundra the Sun never sets now in the short summer seeds that survive the winter germinate tundra plants flower and produce seeds during the six weeks or so when the temperature stays above freezing this allows plants to complete their entire life cycles before the return of Winter the summer flush of plant growth increases the food available for tundra animals the musk oxin that had to Paw the snow to get at plants now have plenty to eat as the food supply increases the number of lemmings increases providing food for Predators like the snowy owl [Music] [Music] owls build their nests in places where they can find the most [Music] Lemmings the more the Lemmings multiply the more food the owl has to feed its young in the summer when food is abundant many animals move north to the tundra great herds of caribou move in a mass migration from the coniferous forests a few hundred miles to the South water fowl migrate thousands of miles to raise their young in the [Music] tundra because there are no trees in this biome only ground nesting species like the Arctic loon can [Music] survive however on the ground eggs are vulnerable to Predators like the arctic fox [Music] [Applause] now the ponds team with insect life mosquito eggs that survived the winter Frozen under the snow and ice have hatched into larv they hang head downward from the water's surface breathing through their tails they will soon become adults and within hours the tundra will be swarming with millions of blood sucking mosquitoes the appearance of these swarms of adult insects occurs at the same time that insect eating birds hatch Birds who Nest here include the Lapland long [Music] spur the golden Plover has flown 8,000 M from Argentina to raise her chicks [Music] here food is so abundant that rdy Turnstone chicks Peck their own food from nearby vegetation the newly born cubs of the Arctic fox grow rapidly in the brief summer of abundance animals like the ground squirrel store food and put on as much fat as possible this is the only Tundra animal that hibernates by August the summer begins drawing rapidly to an [Music] end some plants like these grass produce fluffy seed [Music] coverings the seeds will be dispersed by the wind and lie dormant until the return of [Music] Summer the growing season is over as the days grow short the land can no longer support its summer population the temperature is dropping the food supply diminishing now the Caribou gather and begin their migration back to the forest south of the tundra [Applause] a [Applause] [Applause] [Applause] migrating birds begin leaving the tundra vast flocks of geese set off on transcontinental flights to the South [Applause] [Music] [Music] the hours of daylight grow shorter [Music] the animals that remain faced months of cold and darkness as winter grips the tundra again [Music] [Music] w for